UDR (UDR) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 06, 2020
Entity information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2020
Entity File Number	1-10524
Entity Registrant Name	UDR, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	54-0857512
Entity Address, Address Line One	1745 Shea Center Drive, Suite 200
Entity Address, City or Town	Highlands Ranch
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80129
City Area Code	720
Local Phone Number	283-6120
Title of 12(b) Security	Common Stock
Trading Symbol	UDR
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		294,886,013
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000074208
Amendment Flag	false
United Dominion Realty L.P.
Entity information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2020
Entity File Number	333-156002-01
Entity Registrant Name	United Dominion Realty, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	54-1776887
Entity Address, Address Line One	1745 Shea Center Drive, Suite 200
Entity Address, City or Town	Highlands Ranch
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80129
City Area Code	720
Local Phone Number	283-6120
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001018254
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned:
Real estate held for investment	$ 12,608,022	$ 12,532,324
Less: accumulated depreciation	(4,231,269)	(4,131,330)
Real estate held for investment, net	8,376,753	8,400,994
Real estate under development (net of accumulated depreciation of $81 and $23, respectively)	95,245	69,754
Real estate held for disposition (net of accumulated depreciation of $41,121 and $0, respectively)	73,529
Total real estate owned, net of accumulated depreciation	8,545,527	8,470,748
Cash and cash equivalents	980	8,106
Restricted cash	21,949	25,185
Notes receivable, net	151,543	153,650
Investment in and advances to unconsolidated joint ventures, net	588,395	588,262
Operating lease right-of-use assets	203,410	204,225
Other assets	179,301	186,296
Total assets	9,691,105	9,636,472
Liabilities:
Secured debt, net	1,144,201	1,149,441
Unsecured debt, net	3,740,937	3,558,083
Operating lease liabilities	197,829	198,558
Real estate taxes payable	33,134	29,445
Accrued interest payable	31,494	45,199
Security deposits and prepaid rent	48,474	48,353
Distributions payable	115,259	109,382
Accounts payable, accrued expenses, and other liabilities	82,254	90,032
Total liabilities	5,393,582	5,228,493
Commitments and contingencies (Note 13)
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	819,133	1,018,665
Equity:
Common stock, $0.01 par value; 350,000,000 shares authorized: 294,881,038 and 294,588,305 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	2,949	2,946
Additional paid-in capital	5,788,471	5,781,975
Distributions in excess of net income	(2,360,636)	(2,462,132)
Accumulated other comprehensive income/(loss), net	(12,870)	(10,448)
Total stockholders' equity	3,464,115	3,358,542
Noncontrolling interests	14,275	30,772
Total equity	3,478,390	3,389,314
Total liabilities and equity	9,691,105	9,636,472
8.00% Series E Cumulative Convertible Preferred Stock
Equity:
Preferred stock, no par value; 50,000,000 shares authorized:	46,200	46,200
Series F
Equity:
Preferred stock, no par value; 50,000,000 shares authorized:	$ 1	$ 1

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Real estate owned:
Real estate under development accumulated depreciation	$ 81	$ 23
Real estate held for disposition accumulated depreciation	$ 41,121	$ 0
Equity:
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	294,881,038	294,588,305
Common stock, shares outstanding	294,881,038	294,588,305
8.00% Series E Cumulative Convertible Preferred Stock
Equity:
Preferred stock, dividend rate percentage	8.00%	8.00%
Preferred stock, shares issued	2,780,994	2,780,994
Preferred stock, shares outstanding	2,780,994	2,780,994
Series F
Equity:
Preferred stock, shares issued	14,543,281	14,691,274
Preferred stock, shares outstanding	14,543,281	14,691,274

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
REVENUES:
Rental income	$ 320,093	$ 267,922
Joint venture management and other fees	$ 1,388	$ 2,751
Type of revenue	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
Total revenues	$ 321,481	$ 270,673
OPERATING EXPENSES:
Property operating and maintenance	49,483	41,939
Real estate taxes and insurance	45,145	36,300
Property management	9,203	7,703
Other operating expenses	4,966	5,646
Real estate depreciation and amortization	155,476	112,468
General and administrative	14,978	12,467
Casualty-related charges/(recoveries), net	1,251
Other depreciation and amortization	2,025	1,656
Total operating expenses	282,527	218,179
Operating income	38,954	52,494
Income/(loss) from unconsolidated entities	3,367	49
Interest expense	(39,317)	(33,542)
Interest income and other income/(expense), net	2,700	9,813
Income/(loss) before income taxes	5,704	28,814
Tax (provision)/benefit, net	(164)	(2,212)
Net income/(loss)	5,540	26,602
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(313)	(2,057)
Net (income)/loss attributable to noncontrolling interests	(6)	(42)
Net income/(loss) attributable to UDR, Inc.	5,221	24,503
Distributions to preferred stockholders - Series E (Convertible)	(1,066)	(1,011)
Net income/(loss) attributable to common stockholders	$ 4,155	$ 23,492
Income/(loss) per weighted average common share - basic	$ 0.01	$ 0.08
Income/(loss) per weighted average common share - diluted	$ 0.01	$ 0.08
Weighted average number of common shares outstanding - Basic	294,457	277,002
Weighted average number of common shares outstanding - diluted	295,160	277,557

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS)
Net income/(loss)	$ 5,540	$ 26,602
Other comprehensive income/(loss), including portion attributable to noncontrolling interests:
Unrealized holding gain/(loss)	(2,917)	(2,210)
(Gain)/loss reclassified into earnings from other comprehensive income/(loss)	357	(945)
Other comprehensive income/(loss), including portion attributable to noncontrolling interests	(2,560)	(3,155)
Comprehensive income/(loss)	2,980	23,447
Comprehensive (income)/loss attributable to noncontrolling interests	(181)	(1,847)
Comprehensive income/(loss) attributable to UDR, Inc.	$ 2,799	$ 21,600

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Preferred Stock	Common Stock	Paid-in Capital	Distributions in Excess of Net Income	Accumulated Other Comprehensive Income/(Loss), net	Noncontrolling Interests	Total
Beginning Balance at Dec. 31, 2018	$ 46,201	$ 2,755	$ 4,920,732	$ (2,063,996)	$ (67)	$ 17,152	$ 2,922,777
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				24,503			24,503
Net income/(loss) attributable to noncontrolling interests						30	30
Contribution of noncontrolling interests in consolidated real estate						125	125
Long Term Incentive Plan Unit grants/(vestings), net						(3,925)	(3,925)
Other comprehensive income/(loss)					(2,903)		(2,903)
Issuance/(forfeiture) of common and restricted shares, net			(1,499)				(1,499)
Issuance of common shares through public offering, net		44	192,135				192,179
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership		19	72,827				72,846
Common stock distributions declared				(96,561)			(96,561)
Preferred stock distributions declared-Series E				(1,011)			(1,011)
Adjustment to reflect redemption value of redeemable noncontrolling interests				(144,197)			(144,197)
Ending Balance at Mar. 31, 2019	46,201	2,818	5,184,195	(2,281,262)	(2,970)	13,382	2,962,364
Beginning Balance at Dec. 31, 2019	46,201	2,946	5,781,975	(2,462,132)	(10,448)	30,772	3,389,314
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				5,221			5,221
Net income/(loss) attributable to noncontrolling interests						(10)	(10)
Long Term Incentive Plan Unit grants/(vestings), net						(16,487)	(16,487)
Other comprehensive income/(loss)					(2,422)		(2,422)
Issuance/(forfeiture) of common and restricted shares, net		1	(1,332)				(1,331)
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership		2	7,828				7,830
Common stock distributions declared				(106,190)			(106,190)
Preferred stock distributions declared-Series E				(1,066)			(1,066)
Adjustment to reflect redemption value of redeemable noncontrolling interests				205,713			205,713
Ending Balance at Mar. 31, 2020	$ 46,201	$ 2,949	$ 5,788,471	(2,360,636)	$ (12,870)	$ 14,275	3,478,390
Consolidated Statements of Changes in Equity
Cumulative effect upon adoption of ASC 326				$ (2,182)			$ (2,182)

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Common stock distributions declared per share	$ 0.36	$ 0.3425
8.00% Series E Cumulative Convertible Preferred Stock
Preferred stock distributions declared	$ 0.3898	$ 0.3708

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net income/(loss)	$ 5,540	$ 26,602
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:
Depreciation and amortization	157,501	114,124
(Income)/loss from unconsolidated entities	(3,367)	(49)
Return on investment in unconsolidated joint ventures	1,741	1,977
Amortization of share-based compensation	6,808	5,937
Other	(1,215)	3,910
Changes in operating assets and liabilities:
(Increase)/decrease in operating assets	114	2,295
Increase/(decrease) in operating liabilities	(31,666)	(17,463)
Net cash provided by/(used in) operating activities	135,456	137,333
Investing Activities
Acquisition of real estate assets	(141,727)	(403,245)
Development of real estate assets	(23,087)	(6,237)
Capital expenditures and other major improvements - real estate assets	(32,983)	(31,264)
Capital expenditures - non-real estate assets	(2,479)	(3,346)
Investment in unconsolidated joint ventures	(16,139)	(21,389)
Distributions received from unconsolidated joint ventures	3,271	10,797
Purchase deposits on pending acquisitions		(10,350)
Repayment/(issuance) of notes receivable, net	(900)	5,285
Net cash provided by/(used in) investing activities	(214,044)	(459,749)
Financing Activities
Payments on secured debt	(2,781)	(962)
Net proceeds from the issuance of unsecured debt	211,320
Net proceeds/(repayment) of commercial paper	(85,000)	(11,115)
Net proceeds/(repayment) of revolving bank debt	58,214	54,294
Proceeds from the issuance of common shares through public offering, net		192,179
Distributions paid to redeemable noncontrolling interests	(7,618)	(8,553)
Distributions paid to preferred stockholders	(1,015)	(959)
Distributions paid to common stockholders	(100,930)	(88,911)
Other	(3,964)	1,706
Net cash provided by/(used in) financing activities	68,226	137,679
Net increase/(decrease) in cash, cash equivalents, and restricted cash	(10,362)	(184,737)
Cash, cash equivalents, and restricted cash, beginning of year	33,291	208,891
Cash, cash equivalents, and restricted cash, end of period	22,929	24,154
Supplemental Information:
Interest paid during the period, net of amounts capitalized	57,320	44,271
Cash paid/(refunds received) for income taxes	323	241
Non-cash transactions:
Transfer of investment in and advances to unconsolidated joint ventures to real estate owned	14,700	40,433
Acquisition of intellectual property in exchange for cancellation of secured note receivable	2,250
Recognition of allowance for credit losses	2,182
Recognition of operating lease right-of-use assets		94,349
Recognition of operating lease liabilities		88,336
Vesting of LTIP Units	23,018	14,335
Development costs and capital expenditures incurred but not yet paid	25,568	10,745
Conversion of Operating Partnership and DownREIT Partnership noncontrolling interests to common stock (167,631 shares in 2020 and 1,838,133 shares in 2019)	7,830	72,846
Dividends declared but not yet paid	$ 115,259	$ 105,548

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS - SUPPLEMENTAL - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
The following reconciles cash, cash equivalents, and restricted cash to amounts as shown above:
Cash and cash equivalents	$ 980	$ 8,106	$ 1,043	$ 185,216
Restricted cash	21,949	25,185	23,111	23,675
Total cash, cash equivalents, and restricted cash as shown above	$ 22,929	$ 33,291	$ 24,154	$ 208,891

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Non-cash transactions:
Conversion of OP Units into common shares	167,631	1,838,133

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2020
BASIS OF PRESENTATION
BASIS OF PRESENTATION	1. BASIS OF PRESENTATION Basis of Presentation UDR, Inc., collectively with our consolidated subsidiaries (“UDR,” the “Company,” “we,” “our,” or “us”), is a self-administered real estate investment trust, or REIT, that owns, operates, acquires, renovates, develops, redevelops, and manages apartment communities. The accompanying consolidated financial statements include the accounts of UDR and its subsidiaries, including United Dominion Realty, L.P. (the “Operating Partnership” or the “OP”) and UDR Lighthouse DownREIT L.P. (the “DownREIT Partnership”). As of March 31, 2020, there were 184.8 million units in the Operating Partnership (“OP Units”) outstanding, of which 176.2 million OP Units (including 0.1 million of general partnership units), or 95.3%, were owned by UDR and 8.6 million OP Units, or 4.7%, were owned by outside limited partners. As of March 31, 2020, there were 32.4 million units in the DownREIT Partnership (“DownREIT Units”) outstanding, of which 18.6 million, or 57.4%, were owned by UDR (including 13.5 million DownREIT Units, or 41.6%, that were held by the Operating Partnership) and 13.8 million, or 42.6%, were owned by outside limited partners. The consolidated financial statements of UDR include the noncontrolling interests of the unitholders in the Operating Partnership and DownREIT Partnership. The accompanying interim unaudited consolidated financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission. Certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted according to such rules and regulations, although management believes that the disclosures are adequate to make the information presented not misleading. In the opinion of management, all adjustments and eliminations necessary for the fair presentation of our financial position as of March 31, 2020, and results of operations for the three months ended March 31, 2020 and 2019, have been included. Such adjustments are normal and recurring in nature. The interim results presented are not necessarily indicative of results that can be expected for a full year, particularly in light of the novel coronavirus disease (“COVID-19”) pandemic and measures intended to mitigate its spread. The accompanying interim unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes for the year ended December 31, 2019 appearing in UDR’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 18, 2020. The accompanying interim unaudited consolidated financial statements are presented in accordance with U.S. generally accepted accounting principles (“GAAP”). GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the dates of the interim unaudited consolidated financial statements and the amounts of revenues and expenses during the reporting periods. Actual amounts realized or paid could differ from those estimates. All significant intercompany accounts and transactions have been eliminated in consolidation. The Company evaluated subsequent events through the date its financial statements were issued. No significant recognized or non-recognized subsequent events were noted other than those noted in Note 2, Significant Accounting Policies, , Real Estate Owned, Secured and Unsecured Debt, Net Subsequent Event

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2020
SIGNIFICANT ACCOUNTING POLICIES
SIGNIFICANT ACCOUNTING POLICIES	2. SIGNIFICANT ACCOUNTING POLICIES Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, basis through a cumulative-effect adjustment to retained earnings of approximately $2.2 million on that date, which was primarily associated with our notes receivable. The Company concluded the cumulative effect was not material to our consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) ​ Principles of Consolidation The Company accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Company first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Company consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest. Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Company generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Company will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Company sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Company will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Company will record a full gain or loss in the period the property is contributed. ​ To the extent that the Company acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Company will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Company will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Company will not recognize a gain or loss on consolidation of a property. ​ Allowance for Credit Losses The Company accounts for allowance for credit losses under the current expected credit loss (“CECL”) impairment model for its financial assets, including trade and other receivables, held-to-maturity debt securities, loans and other financial instruments, and presents the net amount of the financial instrument expected to be collected. The CECL impairment model excludes operating lease receivables. The CECL impairment model requires an estimate of expected credit losses, measured over the contractual life of an instrument, that considers forecasts of future economic conditions in addition to information about past events and current conditions. Based on this model, we analyze the following criteria, as applicable in developing allowances for credit losses: historical loss information, the borrower’s ability to make scheduled payments, the remaining time to maturity, the value of underlying collateral, projected future performance of the borrower and macroeconomic trends. ​ The Company measures credit losses of financial assets on a collective (pool) basis when similar risk characteristics exist. If the Company determines that a financial asset does not share risk characteristics with its other financial assets, the Company evaluates the financial asset for expected credit losses on an individual basis. Allowance for credit losses are recorded as a direct reduction from an asset’s amortized cost basis. Credit losses and recoveries are recorded in Interest income and other income/(expense), net ​ The Company has made the optional election provided by the standard not to measure allowance for credit losses for accrued interest receivables as the Company writes off any uncollectible accrued interest receivables in a timely manner. The Company periodically evaluates the collectability of its accrued interest receivables. A write-off is recorded when the Company concludes that all or a portion of its accrued interest receivable balance is no longer collectible. ​ Notes Receivable Notes receivable relate to financing arrangements which are typically secured by real estate, real estate related projects or other assets. Certain of the loans we extend may include characteristics such as options to purchase the project within a specific time window following expected project completion. These characteristics can cause the loans to fall under the definition of a VIE, and thus trigger consolidation consideration. We consider the facts and circumstances pertinent to each loan, including the relative amount of financing we are contributing to the overall project cost, decision making rights or control we hold, and our rights to expected residual gains or our obligations to absorb expected residual losses from the project. If we are deemed to be the primary beneficiary of a VIE due to holding a controlling financial interest, the majority of decision making control, or by other means, consolidation of the VIE would be required. The Company has concluded that it is not the primary beneficiary of the borrowing entities which were deemed to be VIEs. Additionally, we analyze each loan arrangement that involves real estate development to consider whether the loan qualifies for accounting as a loan or as an investment in a real estate development project. The Company has evaluated its real estate loans, where appropriate, for accounting treatment as loans versus real estate development projects, as required by ASC 310-10. For each loan, the Company has concluded that the characteristics and the facts and circumstances indicate that loan accounting treatment is appropriate. The following table summarizes our Notes receivable, net dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due April 2020 (a) 12.00 % $ 20,000 ​ $ 20,000 Note due October 2020 (b) 8.00 % — ​ 2,250 Note due October 2022 (c) 4.75 % 115,000 ​ 115,000 Note due January 2023 (d) ​ 10.00 % ​ 17,300 ​ ​ 16,400 Notes Receivable ​ ​ ​ ​ 152,300 ​ ​ 153,650 Allowance for credit losses ​ ​ ​ ​ (757) ​ ​ — Total notes receivable, net ​ $ 151,543 ​ $ 153,650 (a) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, all of which has been funded. The note is secured by a parcel of land and related land improvements. Interest payments up to December 2019 are due when the loan matures and interest payments after December 2019 are due monthly. In April 2020, the terms of the secured note were amended to extend the term to May 30, 2022, to adjust the interest rate to 8.0% and to add some covenants of the Borrower. (b) In March 2020, the Company entered into a purchase agreement to acquire all of the unaffiliated third party’s intellectual property in exchange for cancellation of the secured note and accrued interest. All property acquired was recorded in Other assets on the Consolidated Balance Sheets. (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $115.0 million, all of which has been funded. Interest payments are due when the loan matures. The note is secured by a first priority deed of trust on an under construction 259 apartment home operating community in Bellevue, Washington, which is expected to be completed in 2020. When the note was funded, the Company also entered into a purchase option agreement and paid a deposit of $10.0 million, which gives the Company the option to acquire the community at a fixed price of $170.0 million. The purchase option must be exercised within 30 days following the date the temporary certificate of occupancy for the residential portion of the project is issued. The deposit is generally nonrefundable other than due to a failure of closing conditions pursuant to the terms of the agreement. If the Company does not exercise the purchase option, or if the Company exercises and fails to close the purchase other than due to seller’s failure or other breaches in the purchase option agreement, per the terms of the agreement, the note will be modified to extend the maturity date to 10 years following the date the temporary certificate of occupancy is issued. Upon modification, the loan will be interest only for the first three years and after such date payments will be based on a 30-year amortization schedule. (d) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, of which $17.3 million has been funded, including $0.9 million funded during the three months ended March 31, 2020. Interest payments are due monthly. The note matures at the earliest of the following: (a) the closing of any private or public capital raising in the amount of $5.0 million or greater; (b) an acquisition; (c) acceleration in the event of default; or (d) January 2023. During 2020, the terms of this secured note were amended to increase the aggregate commitment from $16.4 million to $20.0 million, to extend the maturity date of the note to January 2023 and for the April 2020 through July 2020 interest payments to be deferred and paid when the note matures The Company recognized $2.6 million and $1.1 million of interest income for the notes receivable described above during the three months ended March 31, 2020 and 2019, respectively, none of which was related party interest. Interest income is included in Interest income and other income/(expense), net Comprehensive Income/(Loss) Comprehensive income/(loss), which is defined as the change in equity during each period from transactions and other events and circumstances from nonowner sources, including all changes in equity during a period except for those resulting from investments by or distributions to stockholders, is displayed in the accompanying Consolidated Statements of Comprehensive Income/(Loss). For the three months ended March 31, 2020 and 2019, the Company’s other comprehensive income/(loss) consisted of the gain/(loss) on derivative instruments that are designated as and qualify as cash flow hedges, (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) into earnings, and the allocation of other comprehensive income/(loss) to noncontrolling interests. The (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) is included in Interest expense Derivatives and Hedging Activity, Income Taxes Due to the structure of the Company as a REIT and the nature of the operations for the operating properties, no provision for federal income taxes has been provided for at UDR. Historically, the Company has generally incurred only state and local excise and franchise taxes. UDR has elected for certain consolidated subsidiaries to be treated as taxable REIT subsidiaries (“TRS”). Income taxes for our TRS are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rate is recognized in earnings in the period of the enactment date. The Company’s deferred tax assets/(liabilities) are generally the result of differing depreciable lives on capitalized assets, temporary differences between book and tax basis of assets and liabilities and timing of expense recognition for certain accrued liabilities. As of March 31, 2020 and December 31, 2019, UDR’s net deferred tax asset/(liability) was $(1.4) million and $(1.6) million, respectively. GAAP defines a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. GAAP also provides guidance on derecognition, classification, interest and penalties, accounting for interim periods, disclosure and transition. The Company recognizes its tax positions and evaluates them using a two-step process. First, UDR determines whether a tax position is more likely than not (greater than 50 percent probability) to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. Second, the Company will determine the amount of benefit to recognize and record the amount that is more likely than not to be realized upon ultimate settlement. The Company invests in assets that qualify for federal investment tax credits (“ITC”) through our TRS. An ITC reduces federal income taxes payable when qualifying depreciable property is acquired. The ITC is determined as a percentage of cost of the assets. The Company accounts for ITCs under the deferral method, under which the tax benefit from the ITC is deferred and amortized as a tax benefit into Tax (provision)/benefit, net Accounts payable, accrued expenses and other liabilities UDR had no material unrecognized tax benefit, accrued interest or penalties at March 31, 2020. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2016 through 2018 remain open to examination by tax jurisdictions to which we are subject. When applicable, UDR recognizes interest and/or penalties related to uncertain tax positions in Tax (provision)/benefit, net ​ Forward Sales Agreements ​ The Company utilizes forward sales agreements for the future issuance of its common stock. When the Company enters into a forward sales agreement, the contract requires the Company to sell its shares to a counterparty at a predetermined price at a future date. The net sales price and proceeds attained by the Company will be determined on the dates of settlement, with adjustments during the term of the contract for the Company’s anticipated dividends as well as for a daily interest factor that varies with changes in the federal funds rate. The Company generally has the ability to determine the dates and method of settlement (i.e., gross physical settlement, net share settlement or cash settlement), subject to certain conditions and the right of the counterparty to accelerate settlement under certain circumstances. ​ The Company accounts for the shares of common stock reserved for issuance upon settlement as equity in accordance with ASC 815-40, Contracts in Entity's Own Equity ​ The guidance establishes a two-step process for evaluating whether an equity-linked financial instrument is considered indexed to its own stock, first, evaluating the instrument’s contingent exercise provisions and second, evaluating the instrument’s settlement provisions. When entering into forward sales agreements, we determined that (i) none of the agreement’s exercise contingencies are based on observable markets or indices besides those related to the market for our own stock price; and (ii) none of the settlement provisions preclude the agreements from being indexed to our own stock. ​ Before the issuance of shares of common stock, upon physical or net share settlement of the forward sales agreements, the Company expects that the shares issuable upon settlement of the forward sales agreements will be reflected in its diluted income/(loss) per share calculations using the treasury stock method. Under this method, the number of shares of common stock used in calculating diluted income/(loss) per share is deemed to be increased by the excess, if any, of the number of shares of common stock that would be issued upon full physical settlement of the forward sales agreements over the number of shares of common stock that could be purchased by the Company in the open market (based on the average market price during the period) using the proceeds receivable upon full physical settlement (based on the adjusted forward sale price at the end of the reporting period). When the Company physically or net share settles any forward sales agreement, the delivery of shares of common stock would result in an increase in the number of weighted average common shares outstanding and dilution to basic income/(loss) per share. (See Note 8, Income/(Loss) per Share

REAL ESTATE OWNED

REAL ESTATE OWNED	3 Months Ended
	Mar. 31, 2020
REAL ESTATE OWNED
REAL ESTATE OWNED	3. REAL ESTATE OWNED Real estate assets owned by the Company consist of income producing operating properties, properties under development, land held for future development, and held for disposition properties. As of March 31, 2020, the Company owned and consolidated 150 communities in 13 states plus the District of Columbia totaling 47,579 apartment homes. The following table summarizes the carrying amounts for our real estate owned (at cost) as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 2,163,055 ​ $ 2,164,032 Depreciable property — held and used: ​ ​ Land improvements ​ 225,850 ​ 224,964 Building, improvements, and furniture, fixtures and equipment ​ 10,178,547 ​ 10,102,758 Real estate intangible assets ​ ​ 40,570 ​ ​ 40,570 Under development: ​ ​ Land and land improvements ​ 29,226 ​ 29,226 Building, improvements, and furniture, fixtures and equipment ​ 66,100 ​ 40,551 Real estate held for disposition: ​ ​ Land and land improvements ​ 16,245 ​ — Building, improvements, and furniture, fixtures and equipment ​ 98,405 ​ — Real estate owned ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Real estate owned, net ​ $ 8,545,527 ​ $ 8,470,748 ​ Acquisitions In January 2020, the Company acquired a 294 apartment home operating community located in Tampa, Florida for approximately $85.2 million. The Company increased its real estate assets owned by approximately $83.1 million and recorded approximately $2.1 million of in-place lease intangibles. In January 2020, the Company increased its ownership interest from 49% to 100% in a 276 apartment home operating community located in Hillsboro, Oregon, for a cash purchase price of approximately $21.6 million. In connection with the acquisition, the Company repaid approximately $35.6 million of joint venture construction financing. As a result, the Company consolidated the operating community. The Company had previously accounted for its 49% ownership interest as a preferred equity investment in an unconsolidated joint venture (see Note 5, Joint Ventures and Partnerships no ​ Dispositions ​ In March 2020, the Company received a nonrefundable deposit on the pending sale of an operating community located in Seattle, Washington. The asset is included in Real estate held for disposition Sheet as of March 31, 2020. The sale is expected to close in the second quarter of 2020 at a gross sales price of $49.7 million. In May 2020, the Company sold an operating community in Seattle, Washington with a total of 196 apartment homes for gross proceeds of $92.9 million, resulting in a gain of approximately $31.7 million. The asset is included in Real estate held for disposition Other Activity Predevelopment, development, and redevelopment projects and related costs are capitalized and reported on the Consolidated Balance Sheets as Total real estate owned, net of accumulated depreciation In connection with the acquisition of certain properties, the Company agreed to pay certain of the tax liabilities of certain contributors if the Company sells one or more of the properties contributed in a taxable transaction prior to the expiration of specified periods of time following the acquisition. The Company may, however, sell, without being required to pay any tax liabilities, any of such properties in a non-taxable transaction, including, but not limited to, a tax-deferred Section 1031 exchange. Further, the Company has agreed to maintain certain debt that may be guaranteed by certain contributors for specified periods of time following the acquisition. The Company, however, has the ability to refinance or repay guaranteed debt or to substitute new debt if the debt and the guaranty continue to satisfy certain conditions.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	3 Months Ended
	Mar. 31, 2020
VARIABLE INTEREST ENTITIES
VARIABLE INTEREST ENTITIES	4. VARIABLE INTEREST ENTITIES The Company has determined that the Operating Partnership and DownREIT Partnership are VIEs as the limited partners lack substantive kick-out rights and substantive participating rights. The Company has concluded that it is the primary beneficiary of, and therefore consolidates, the Operating Partnership and DownREIT Partnership based on its role as the sole general partner of the Operating Partnership and DownREIT Partnership. The Company’s role as community manager and its equity interests give us the power to direct the activities that most significantly impact the economic performance and the obligation to absorb potentially significant losses or the right to receive potentially significant benefits of the Operating Partnership and DownREIT Partnership. See the consolidated financial statements of the Operating Partnership presented within this Report and Note 4, Unconsolidated Entities

JOINT VENTURES AND PARTNERSHIPS

JOINT VENTURES AND PARTNERSHIPS	3 Months Ended
	Mar. 31, 2020
JOINT VENTURES AND PARTNERSHIPS
JOINT VENTURES AND PARTNERSHIPS	5. JOINT VENTURES AND PARTNERSHIPS UDR has entered into joint ventures and partnerships with unrelated third parties to own, operate, acquire, renovate, develop, redevelop, dispose of, and manage real estate assets that are either consolidated and included in Real estate owned Investment in and advances to unconsolidated joint ventures, net Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest. UDR’s joint ventures and partnerships are funded with a combination of debt and equity. Our losses are typically limited to our investment and except as noted below, the Company does not guarantee any debt, capital payout or other obligations associated with our joint ventures and partnerships. The Company recognizes earnings or losses from our investments in unconsolidated joint ventures and partnerships consisting of our proportionate share of the net earnings or losses of the joint ventures and partnerships. In addition, we may earn fees for providing management services to the unconsolidated joint ventures and partnerships. The following table summarizes the Company’s investment in and advances to unconsolidated joint ventures and partnerships, net, which are accounted for under the equity method of accounting as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Number of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating ​ Apartment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ Communities ​ Homes ​ Investment at ​ UDR’s Ownership Interest ​ ​ Three Months Ended ​ Location of March 31, March 31, March 31, December 31, ​ March 31, ​ December 31, ​ March 31, Joint Venture Properties 2020 2020 2020 2019 ​ 2020 ​ 2019 ​ 2020 2019 Operating: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR/MetLife I ​ Los Angeles, CA ​ 1 ​ 150 ​ $ 28,570 ​ $ 28,812 ​ 50.0 % ​ 50.0 % ​ $ (454) ​ $ (576) UDR/MetLife II Various 7 1,250 ​ 150,652 ​ 150,893 ​ 50.0 % ​ 50.0 % ​ ​ (91) ​ ​ 434 Other UDR/MetLife Joint Ventures Various 5 1,437 ​ 94,109 ​ 98,441 ​ 50.6 % ​ 50.6 % ​ ​ (1,811) ​ ​ (1,777) West Coast Development Joint Ventures ​ Los Angeles, CA ​ 1 ​ 293 ​ ​ 34,943 ​ ​ 34,907 ​ 47.0 % ​ 47.0 % ​ ​ (77) ​ ​ (149) Sold Joint Ventures ​ ​ ​ ​ ​ ​ ​ ​ — ​ ​ — ​ — % ​ — % ​ ​ — ​ ​ (1,819) Investment in and advances to unconsolidated joint ventures, net, before preferred equity investments and other investments ​ $ 308,274 ​ $ 313,053 ​ ​ ​ ​ $ (2,433) ​ $ (3,887) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment at ​ Three Months Ended ​ Developer Capital Program ​ ​ Years To ​ UDR March 31, December 31, March 31, ​ and Other Investments (a) Location Rate Maturity ​ Commitment (b) 2020 2019 2020 2019 ​ Preferred equity investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ West Coast Development Joint Ventures (c) Hillsboro, OR 6.5 % N/A ​ $ — ​ $ — ​ $ 17,064 ​ $ (46) ​ $ (161) ​ 1532 Harrison ​ San Francisco, CA ​ 11.0 % 2.3 ​ ​ 24,645 ​ ​ 31,426 ​ ​ 30,585 ​ ​ 836 ​ ​ 748 ​ 1200 Broadway (d) ​ Nashville, TN ​ 8.0 % 2.5 ​ ​ 55,558 ​ ​ 65,254 ​ ​ 63,958 ​ ​ 1,281 ​ ​ 1,169 ​ Junction ​ Santa Monica, CA ​ 12.0 % 2.3 ​ ​ 8,800 ​ ​ 10,693 ​ ​ 10,379 ​ ​ 314 ​ ​ 275 ​ 1300 Fairmount (d) ​ Philadelphia, PA ​ Variable ​ 3.4 ​ ​ 51,393 ​ ​ 55,840 ​ ​ 51,215 ​ ​ 1,166 ​ ​ 275 ​ Essex ​ Orlando, FL ​ 12.5 % 3.4 ​ ​ 12,886 ​ ​ 15,270 ​ ​ 14,804 ​ ​ 466 ​ ​ 332 ​ Modera Lake Merritt (d) ​ Oakland, CA ​ 9.0 % 4.0 ​ ​ 27,250 ​ ​ 28,653 ​ ​ 22,653 ​ ​ 574 ​ ​ — ​ Thousand Oaks (e) ​ Thousand Oaks, CA ​ 9.0 % 4.9 ​ ​ 20,059 ​ ​ 5,994 ​ ​ — ​ ​ 24 ​ ​ — ​ Other investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Portals ​ Washington, D.C. ​ 11.0 % 1.2 ​ ​ 38,559 ​ ​ 49,323 ​ ​ 48,181 ​ ​ 1,335 ​ ​ 1,173 ​ Other investment ventures ​ N/A ​ N/A ​ N/A ​ $ 34,500 ​ ​ 14,364 ​ ​ 13,598 ​ ​ (150) ​ ​ 125 ​ Total Developer Capital Program and Other Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 276,817 ​ ​ 272,437 ​ ​ 5,800 ​ ​ 3,936 ​ Total Joint Ventures and Developer Capital Program Investments, net (f) ​ ​ ​ ​ $ 585,091 ​ $ 585,490 ​ $ 3,367 $ 49 ​ (a) The Developer Capital Program is the program through which the Company makes investments, including preferred equity investments, mezzanine loans or other structured investments that may receive a fixed yield on the investment and may include provisions pursuant to which the Company participates in the increase in value of the property upon monetization of the applicable property and/or holds fixed price purchase options. (b) Represents UDR’s maximum funding commitment only and therefore excludes other activity such as income from investments. (c) In January 2020, the Company increased its ownership interest from 49% to 100% in the 276 apartment home operating community located in Hillsboro, Oregon, for a cash purchase price of approximately $21.6 million. As a result, the Company consolidated the operating community and it is no longer accounted for as a preferred equity investment in an unconsolidated joint venture (see Note 3, Real Estate Owned ). In connection with the purchase, the Company repaid the joint venture’s construction loan of approximately $35.6 million. (d) The Company’s preferred equity investment receives a variable percentage of the value created from the project upon a capital or liquidating event. (e) In February 2020, the Company entered into a joint venture agreement with an unaffiliated joint venture partner to develop and operate a 142 apartment home community in Thousand Oaks, CA. The Company’s preferred equity investment of up to $20.1 million earns a preferred return of 9.0% per annum and receives a variable percentage of the value created from the project upon a capital or liquidating event. The unaffiliated joint venture partner is the managing member of the joint venture and the developer of the community. The Company has concluded that it does not control the joint venture and, therefore, accounts for it under the equity method of accounting. (f) As of March 31, 2020, the Company’s negative investment in 13 th and Market Properties LLC of $3.3 million is included in Other UDR/MetLife Joint Ventures in the table above and recorded in Accounts payable, accrued expenses, and other liabilities on the Consolidated Balance Sheet. As of March 31, 2020 and December 31, 2019, the Company had deferred fees of $9.0 million and $9.0 million, respectively, which will be recognized through earnings over the weighted average life of the related properties, upon the disposition of the properties to a third party, or upon completion of certain development obligations. The Company recognized management fees of $1.4 million and $ 2.8 million for the three months ended March 31, 2020 and 2019, respectively, for management of the communities held by the joint ventures and partnerships. The management fees are included in Joint venture management and other fees on the Consolidated Statements of Operations. The Company may, in the future, make additional capital contributions to certain of our joint ventures and partnerships should additional capital contributions be necessary to fund acquisitions or operations. We evaluate our investments in unconsolidated joint ventures and partnerships when events or changes in circumstances indicate that there may be an other-than-temporary decline in value. We consider various factors to determine if a decrease in the value of the investment is other-than-temporary. The Company did not recognize any other-than-temporary impairments in the value of its investments in unconsolidated joint ventures or partnerships during the three months ended March 31, 2020 and 2019. Combined summary balance sheets relating to the unconsolidated joint ventures’ and partnerships’ (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,868,502 $ 1,901,081 Cash and cash equivalents ​ 32,486 ​ 29,823 Other assets ​ ​ 180,893 ​ 172,941 Total assets $ 2,081,881 $ 2,103,845 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,136,306 ​ $ 1,148,048 Accounts payable and accrued liabilities ​ ​ 50,262 ​ ​ 55,114 Total liabilities ​ 1,186,568 ​ 1,203,162 Total equity $ 895,313 $ 900,683 ​ Combined summary financial information relating to the unconsolidated joint ventures’ and partnerships’ operations (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenues $ 41,314 $ 81,532 Property operating expenses ​ 15,297 ​ 30,312 Real estate depreciation and amortization ​ 16,243 ​ 29,580 Operating income/(loss) ​ 9,774 ​ ​ 21,640 Interest expense ​ (10,347) ​ (21,924) Net unrealized gain/(loss) on held investments ​ ​ — ​ ​ 1,522 Other income/(loss) ​ ​ (8) ​ ​ 103 Net income/(loss) $ (581) $ 1,341 (1)

LEASES

LEASES	3 Months Ended
	Mar. 31, 2020
LEASES
LEASES	6. LEASES Lessee - Ground Leases UDR owns six communities that are subject to ground leases, under which UDR is the lessee, expiring between 2043 and 2103, inclusive of extension options we are reasonably certain will be exercised. All of these leases are classified as operating leases through the lease term expiration based on our election of the practical expedient provided by the leasing standard. Rental expense for lease payments related to operating leases is recognized on a straight-line basis over the remaining lease term. We currently do not hold any finance leases. The Company also elected the short-term lease exception provided by the leasing standard and therefore only recognizes right-of-use assets and lease liabilities for leases with a term greater than one year. No leases qualified for the short-term lease exception during the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Operating lease right-of-use assets Operating lease liabilities Operating lease right-of-use assets Operating lease liabilities As the discount rate implicit in the leases was not readily determinable, we determined the discount rate for these leases utilizing the Company’s incremental borrowing rate at a portfolio level, adjusted for the remaining lease term, and the form of underlying collateral. The weighted average remaining lease term for these leases was 44.5 years at March 31, 2020 and the weighted average discount rate was 5.0% at March 31, 2020. Future minimum lease payments and total operating lease liabilities from our ground leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2020 ​ $ 9,330 2021 ​ ​ 12,442 2022 ​ ​ 12,442 2023 ​ ​ 12,442 2024 ​ ​ 12,442 Thereafter ​ ​ 455,221 Total future minimum lease payments (undiscounted) ​ ​ 514,319 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) Total operating lease liabilities (discounted) ​ $ 197,829 ​ For purposes of recognizing our ground lease contracts, the Company uses the minimum lease payments, if stated in the agreement. For ground lease agreements where there is a rent reset provision based on a change in an index or a rate (i.e., changes in fair market rental rates or changes in the consumer price index) but that does not include a specified minimum lease payment, the Company uses the current rent over the remainder of the lease term. If there is a contingency upon which some or all of the variable lease payments that will be paid over the remainder of the lease term are based, which is resolved such that those payments now meet the definition of lease payments, the Company will remeasure the right-of-use asset and lease liability on the reset date. The components of operating lease expenses were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2020 ​ 2019 Lease expense: ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,170 ​ $ 2,159 Variable lease expense (a) ​ ​ 43 ​ ​ 139 Total operating lease expense (b)(c) ​ $ 3,213 ​ $ 2,298 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.8 million and $0.7 million, respectively, and for the three months ended March 31, 2019 Operating lease right-of-use assets and Operating lease liabilities amortized by $0.2 million and $0.1 million, respectively. The Company recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization. ​ Lessor - Apartment Home, Retail and Commercial Space Leases ​ UDR’s communities and retail and commercial space are leased to tenants under operating leases. As of March 31, 2020, our apartment home leases generally have initial terms of 12 months or less and represent approximately 98.4% of our total lease revenue. As of March 31, 2020, our retail and commercial space leases generally have initial terms of between 5 and 15 years and represent approximately 1.6% of our total lease revenue. Our apartment home leases are generally renewable at the end of the lease term, subject to potential increases in rental rates, and our retail and commercial space leases generally have renewal options, subject to associated increases in rental rates due to market based or fixed price renewal options and certain other conditions. (See Note 14, Reportable Segments ​ Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 16,849 2021 ​ ​ 22,487 2022 ​ ​ 20,781 2023 ​ ​ 19,317 2024 ​ ​ 17,594 Thereafter ​ ​ 81,662 Total future minimum lease payments (a) ​ $ 178,690 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months or less. Certain of our leases with retail and commercial tenants provide for the payment by the lessee of additional variable rent based on a percentage of the tenant’s revenue. The amounts shown in the table above do not include these variable percentage rents. The Company recorded variable percentage rents of $0.1 million and less than $0.2 million during the three months ended March 31, 2020 and 2019, respectively.

SECURED AND UNSECURED DEBT, NET

SECURED AND UNSECURED DEBT, NET	3 Months Ended
	Mar. 31, 2020
SECURED AND UNSECURED DEBT, NET
SECURED AND UNSECURED DEBT, NET	7. SECURED AND UNSECURED DEBT, NET The following is a summary of our secured and unsecured debt at March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ March 31, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2020 2019 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 883,249 ​ $ 884,869 3.61 % 5.9 15 Credit facilities (b) ​ 203,429 ​ 204,590 4.90 % 2.8 4 Deferred financing costs and other non-cash adjustments ​ 30,585 ​ 33,046 Total fixed rate secured debt, net ​ 1,117,263 ​ 1,122,505 3.85 % 5.3 19 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, net ​ 1,144,201 ​ 1,149,441 3.80 % 5.5 20 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2023 (d) (m) ​ 50,000 ​ — 1.75 % 2.8 Borrowings outstanding under unsecured commercial paper program due April 2020 (e) (m) (n) ​ ​ 215,000 ​ ​ 300,000 ​ 1.58 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2021 ​ 24,797 ​ 16,583 1.82 % 0.8 Term Loan due September 2023 (d) (m) ​ 35,000 ​ 35,000 2.48 % 3.5 Fixed Rate Debt ​ ​ 1.93% Term Loan due September 2023 (d) (m) ​ ​ 315,000 ​ 315,000 1.93 % 3.5 ​ ​ 3.75% Medium-Term Notes due July 2024 (net of discounts of $443 and $470, respectively) (g) (m) ​ 299,557 ​ 299,530 3.75 % 4.3 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 4.5 4.00% Medium-Term Notes due October 2025 (net of discounts of $379 and $396, respectively) (h) (m) ​ 299,621 ​ 299,604 4.00 % 5.5 2.95% Medium-Term Notes due September 2026 (m) ​ 300,000 ​ 300,000 2.95 % 6.4 3.50% Medium-Term Notes due July 2027 (net of discounts of $511 and $529, respectively) (m) ​ ​ 299,489 ​ ​ 299,471 ​ 3.50 % 7.3 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $924 and $954, respectively) (m) ​ ​ 299,076 ​ ​ 299,046 ​ 3.50 % 7.8 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $5 and $5, respectively) (i) (m) ​ ​ 299,995 ​ ​ 299,995 ​ 4.40 % 8.8 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $13,442 and $2,281, respectively) (j) (m) ​ ​ 613,442 ​ ​ 402,281 ​ 3.20 % 9.8 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of discounts of $1,099 and $1,123, respectively) (k) (m) ​ ​ 398,901 ​ ​ 398,877 ​ 3.00 % 11.4 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $1,287 and $1,309, respectively) (l) (m) ​ ​ 298,713 ​ ​ 298,691 ​ 3.10 % 14.6 ​ ​ Other ​ 12 ​ 13 Deferred financing costs ​ (23,310) ​ (21,652) Total Unsecured Debt, net ​ 3,740,937 ​ 3,558,083 3.29 % 7.5 Total Debt, net ​ $ 4,885,138 ​ $ 4,707,524 3.28 % 7.1 ​ For purposes of classification of the above table, variable rate debt with a derivative financial instrument designated as a cash flow hedge is deemed as fixed rate debt due to the Company having effectively established a fixed interest rate for the underlying debt instrument. Our secured debt instruments generally feature either monthly interest and principal or monthly interest-only payments with balloon payments due at maturity. As of March 31, 2020, secured debt encumbered $2.1 billion or 16.6% of UDR’s total real estate owned based upon gross book value ($10.7 billion or 83.4% of UDR’s real estate owned based on gross book value is unencumbered). (a) The Company will from time to time acquire properties subject to fixed rate debt instruments. In those situations, the Company records the debt at its estimated fair value and amortizes any difference between the fair value and par value to interest expense over the life of the underlying debt instrument. (b) During the three months ended March 31, 2020 and 2019, the Company had $2.6 million and $0.6 million, respectively, of amortization of the fair market adjustment of debt assumed in the acquisition of properties inclusive of its fixed rate mortgage notes payable and credit facilities, which was included in Interest expense ​ (c) (d) six-month extension options, subject to certain conditions. The Term Loan has a scheduled maturity date of September 30, 2023. Based on the Company’s current credit rating, the Revolving Credit Facility has an interest rate equal to LIBOR plus a margin of 82.5 basis points and a facility fee of 15 basis points, and the Term Loan has an interest rate equal to LIBOR plus a margin of 90 basis points. Depending on the Company’s credit rating, the margin under the Revolving Credit Facility ranges from 75 to 145 basis points, the facility fee ranges from 10 to 30 basis points, and the margin under the Term Loan ranges from 80 to 165 basis points. The Credit Agreement contains customary representations and warranties and financial and other affirmative and negative covenants. The Credit Agreement also includes customary events of default, in certain cases subject to customary periods to cure. The occurrence of an event of default, following the applicable cure period, would permit the lenders to, among other things, declare the unpaid principal, accrued and unpaid interest and all other amounts payable under the Credit Agreement to be immediately due and payable. The following is a summary of short-term bank borrowings under the Revolving Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 2019 ​ Total revolving credit facility ​ $ 1,100,000 ​ $ 1,100,000 ​ Borrowings outstanding at end of period (1) ​ 50,000 ​ — ​ Weighted average daily borrowings during the period ended ​ 11,538 ​ 55 ​ Maximum daily borrowings during the period ended ​ 50,000 ​ 20,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.6 % Interest rate at end of the period ​ 1.8 % — % (1) Excludes $2.5 million and $2.9 million of letters of credit at March 31, 2020 and December 31, 2019, respectively . (e) The following is a summary of short-term bank borrowings under the unsecured commercial paper program at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total unsecured commercial paper program $ 500,000 ​ $ 500,000 ​ Borrowings outstanding at end of period ​ 215,000 ​ 300,000 ​ Weighted average daily borrowings during the period ended ​ 346,978 ​ 173,353 ​ Maximum daily borrowings during the period ended ​ 500,000 ​ 435,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.5 % Interest rate at end of the period ​ 1.6 % 2.0 % ​ (f) 82.5 basis points. Depending on the Company’s credit rating, the margin ranges from 75 to 145 basis points. The following is a summary of short-term bank borrowings under the Working Capital Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total working capital credit facility ​ $ 75,000 ​ $ 75,000 ​ Borrowings outstanding at end of period ​ 24,797 ​ 16,583 ​ Weighted average daily borrowings during the period ended ​ 25,212 ​ 23,487 ​ Maximum daily borrowings during the period ended ​ 46,419 ​ 66,170 ​ Weighted average interest rate during the period ended ​ 2.2 % 3.1 % Interest rate at end of the period ​ 1.8 % 2.6 % ​ (g) (h) (i) (j) In February 2020, the Company issued $200.0 million of 3.20% senior unsecured medium-term notes due 2030. Interest is payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2020. The notes were priced at 105.660% of the principal amount at issuance. This was a further issuance of the 2030 notes, and forms a single series with, the $300.0 million aggregate principal amount of the Company’s 3.20% notes due 2030 that were issued in July 2019 and the $100.0 million aggregate principal amount of the Company’s 3.20% notes due 2030 that were issued in October 2019. As of the completion of the offering, the aggregate principal amount of outstanding 2030 notes was $600.0 million. (k) (l) . (m) The aggregate maturities, including amortizing principal payments on secured and unsecured debt, of total debt for the next ten calendar years subsequent to March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2020 ​ $ 112,592 ​ $ — ​ $ 112,592 ​ $ 215,000 (a) $ 327,592 2021 ​ ​ 8,763 ​ ​ — ​ ​ 8,763 ​ ​ 24,797 ​ ​ 33,560 2022 ​ 9,159 ​ — ​ 9,159 ​ — ​ 9,159 2023 ​ 295,965 ​ — ​ 295,965 ​ 400,000 ​ 695,965 2024 ​ 95,280 ​ — ​ 95,280 ​ 315,644 ​ 410,924 2025 ​ 173,189 ​ — ​ 173,189 ​ 300,000 ​ 473,189 2026 ​ 51,070 ​ — ​ 51,070 ​ 300,000 ​ 351,070 2027 ​ 1,111 ​ — ​ 1,111 ​ 300,000 ​ 301,111 2028 ​ 122,465 ​ — ​ 122,465 ​ 300,000 ​ 422,465 2029 ​ 144,584 ​ — ​ 144,584 ​ 300,000 ​ 444,584 Thereafter ​ 72,500 ​ 27,000 ​ 99,500 ​ 1,300,000 ​ 1,399,500 Subtotal ​ 1,086,678 ​ 27,000 ​ 1,113,678 ​ 3,755,441 ​ 4,869,119 Non-cash (b) ​ 30,585 ​ (62) ​ 30,523 ​ (14,504) ​ 16,019 Total ​ $ 1,117,263 ​ $ 26,938 ​ $ 1,144,201 ​ $ 3,740,937 ​ $ 4,885,138 (a) All unsecured debt due in the remainder of 2020 is related to the Company’s commercial paper program. (b) Includes the unamortized balance of fair market value adjustments, premiums/discounts and deferred financing costs . The Company amortized $1.0 million and $1.0 million, respectively, during the three months ended March 31, 2020 and 2019, of deferred financing costs into Interest expense. We were in compliance with the covenants of our debt instruments at March 31, 2020. (n)

INCOME_(LOSS) PER SHARE

INCOME/(LOSS) PER SHARE	3 Months Ended
	Mar. 31, 2020
INCOME/(LOSS) PER SHARE
INCOME/(LOSS) PER SHARE	8. INCOME/(LOSS) PER SHARE The following table sets forth the computation of basic and diluted income/(loss) per share for the periods presented (dollars and shares in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 ​ Numerator for income/(loss) per share: ​ ​ ​ ​ ​ ​ Net income/(loss) ​ $ 5,540 ​ $ 26,602 ​ Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) ​ Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) ​ Net income/(loss) attributable to UDR, Inc. ​ 5,221 ​ 24,503 ​ Distributions to preferred stockholders — Series E (Convertible) ​ (1,066) ​ (1,011) ​ Income/(loss) attributable to common stockholders - basic and diluted ​ $ 4,155 ​ $ 23,492 ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for income/(loss) per share: ​ ​ ​ Weighted average common shares outstanding ​ 294,731 ​ 277,297 ​ Non-vested restricted stock awards ​ (274) ​ (295) ​ Denominator for basic income/(loss) per share ​ 294,457 ​ 277,002 ​ Incremental shares issuable from assumed conversion of unvested LTIP Units and unvested restricted stock ​ 703 ​ 555 ​ Denominator for diluted income/(loss) per share ​ 295,160 ​ 277,557 ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) per weighted average common share: ​ ​ ​ Basic ​ $ 0.01 ​ $ 0.08 ​ Diluted ​ $ 0.01 ​ $ 0.08 ​ ​ Basic income/(loss) per common share is computed based upon the weighted average number of common shares outstanding. Diluted income/(loss) per common share is computed based upon the weighted average number of common shares outstanding plus the common shares issuable from the assumed conversion of the OP Units and DownREIT Units, convertible preferred stock, stock options, unvested long-term incentive plan units (“LTIP Units”), unvested restricted stock and continuous equity program forward sales agreements. Only those instruments having a dilutive impact on our basic income/(loss) per share are included in diluted income/(loss) per share during the periods. For the three months ended March 31, 2020 and 2019, the effect of the conversion of the OP Units, DownREIT Units, LTIP Units, the Company’s Series E preferred stock and shares issuable upon settlement of forward sales agreements was not dilutive and therefore not included in the above calculation. In July 2017, the Company entered into an ATM sales agreement under which the Company may offer and sell up to 20.0 million shares of its common stock, from time to time, to or through its sales agents and may enter into separate forward sales agreements to or through its forward purchasers. Upon entering into the ATM sales agreement, the Company simultaneously terminated the sales agreement for its prior at-the-market equity offering program, which was entered into in April 2017, which replaced the prior at-the-market equity offering program entered into in April 2012. During the three months ended March 31, 2020, the Company did not sell any shares of common stock through its ATM program. As of March 31, 2020, we had 11.7 million shares of common stock available for future issuance under the ATM program, including an aggregate of 2.1 million shares subject to the forward sales agreements described below. In connection with any forward sales agreement under the Company’s ATM program, the relevant forward purchasers will borrow from third parties and, through the relevant sales agent, acting in its role as forward seller, sell a number of shares of the Company’s common stock equal to the number of shares underlying the agreement. The Company does not initially receive any proceeds from any sale of borrowed shares by the forward seller. ​ During the three months ended March 31, 2020, the Company entered into forward sales agreements under its ATM program for a total of 2.1 million shares of common stock at a weighted average initial forward price per share of $49.56. The initial forward price per share to be received by the Company upon settlement will be determined on the applicable settlement date based on adjustments made to the initial forward price to reflect the then-current federal funds rate and the amount of dividends paid to holders of UDR common stock over the term of the forward sales agreement. As of March 31, 2020, no shares under the forward sales agreements have been settled. The final dates by which shares sold under the forward sales agreements must be settled range between February 12, 2021 and March 3, 2021. ​ The Company generally has the ability to determine the dates and method of settlement (i.e., gross physical settlement, net share settlement or cash settlement), subject to certain conditions and the right of the counterparty to accelerate settlement under certain circumstances. The Company currently expects to fully physically settle each forward sales agreement with the relevant forward purchaser on one or more dates specified by the Company on or prior to the maturity date of that particular forward sales agreement, in which case the Company expects to receive aggregate net cash proceeds at settlement equal to the number of shares underlying the particular forward sales agreement multiplied by the relevant forward sale price. However, subject to certain exceptions, the Company may also elect, in its discretion, to cash settle or net share settle a particular forward sales agreement, in which case the Company may not receive any proceeds (in the case of cash settlement) or will not receive any proceeds (in the case of net share settlement), and the Company may owe cash (in the case of cash settlement) or shares of UDR common stock (in the case of net share settlement) to the relevant forward purchaser. ​ The following table sets forth the additional shares of common stock issuable, by equity instrument, if such equity instrument were converted to or redeemed for common stock for each of the three months ended March 31, 2020 and 2019 (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2020 ​ 2019 ​ OP/DownREIT Units 22,228 24,280 Convertible preferred stock 3,011 3,011 Unvested LTIP Units and unvested restricted stock 703 555 ​

NONCONTROLLING INTERESTS

NONCONTROLLING INTERESTS	3 Months Ended
	Mar. 31, 2020
NONCONTROLLING INTERESTS
NONCONTROLLING INTERESTS	9. NONCONTROLLING INTERESTS Redeemable Noncontrolling Interests in the Operating Partnership and DownREIT Partnership Interests in the Operating Partnership and the DownREIT Partnership held by limited partners are represented by OP Units and DownREIT Units, respectively. The income is allocated to holders of OP Units/DownREIT Units based upon net income attributable to common stockholders and the weighted average number of OP Units/DownREIT Units outstanding to total common shares plus OP Units/DownREIT Units outstanding during the period. Capital contributions, distributions, and profits and losses are allocated to noncontrolling interests in accordance with the terms of the partnership agreements of the Operating Partnership and the DownREIT Partnership. Limited partners of the Operating Partnership and the DownREIT Partnership have the right to require such partnership to redeem all or a portion of the OP Units/DownREIT Units held by the limited partner at a redemption price equal to and in the form of the Cash Amount (as defined in the partnership agreement of the Operating Partnership or the DownREIT Partnership, as applicable), provided that such OP Units/DownREIT Units have been outstanding for at least one year, subject to certain exceptions. UDR, as the general partner of the Operating Partnership and the DownREIT Partnership may, in its sole discretion, purchase the OP Units/DownREIT Units by paying to the limited partner either the Cash Amount or the REIT Share Amount (generally one share of common stock of the Company for each OP Unit/DownREIT Unit), as defined in the partnership agreement of the Operating Partnership or the DownREIT Partnership, as applicable. Accordingly, the Company records the OP Units/DownREIT Units outside of permanent equity and reports the OP Units/DownREIT Units at their redemption value using the Company’s stock price at each balance sheet date. The following table sets forth redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership for the following period ( dollars in thousands ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, December 31, 2019 $ 1,018,665 ​ Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (205,713) ​ Conversion of OP Units/DownREIT Units to Common Stock ​ (7,830) ​ Net income/(loss) attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ 313 ​ Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (9,182) ​ Vesting of Long-Term Incentive Plan Units ​ ​ 23,018 ​ Allocation of other comprehensive income/(loss) ​ (138) ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, March 31, 2020 ​ $ 819,133 ​ ​ Noncontrolling Interests Noncontrolling interests represent interests of unrelated partners and unvested LTIP Units in certain consolidated affiliates, and are presented as part of equity on the Consolidated Balance Sheets since these interests are not redeemable. Net (income)/loss attributable to noncontrolling interests The Company grants LTIP Units to certain employees and non-employee directors. The LTIP Units represent an ownership interest in the Operating Partnership and have vesting terms of between one Noncontrolling interests related to long-term incentive plan units represent the unvested LTIP Units of these employees and non-employee directors in the Operating Partnership. The net income/(loss) allocated to the unvested LTIP Units is included in Net (income)/loss attributable to noncontrolling interests

FAIR VALUE OF DERIVATIVES AND F

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2020
FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS
FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS	10. FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS Fair value is based on the price that would be received to sell an asset or the exit price that would be paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level valuation hierarchy prioritizes observable and unobservable inputs used to measure fair value. The fair value hierarchy consists of three broad levels, which are described below: ● Level 1 — Quoted prices in active markets for identical assets or liabilities that the entity has the ability to access. ● Level 2 — Observable inputs other than prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated with observable market data. ● Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The estimated fair values of the Company’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 Total assets ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 3,075 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 903,243 ​ ​ 908,088 ​ ​ — ​ ​ — ​ ​ 908,088 Credit facilities ​ 216,181 ​ 213,026 ​ — ​ — ​ 213,026 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ Revolving credit facility ​ ​ 50,000 ​ ​ 50,000 ​ ​ — ​ ​ — ​ ​ 50,000 Working capital credit facility ​ ​ 24,797 ​ ​ 24,797 ​ ​ — ​ ​ — ​ ​ 24,797 Commercial paper program ​ ​ 215,000 ​ ​ 215,000 ​ ​ — ​ ​ — ​ ​ 215,000 Unsecured notes ​ ​ 3,474,450 ​ ​ 3,466,082 ​ ​ — ​ ​ — ​ ​ 3,466,082 Total liabilities ​ $ 4,913,746 ​ $ 4,907,068 ​ $ — ​ $ 3,075 ​ $ 4,903,993 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 819,133 ​ $ 819,133 ​ $ — ​ $ 819,133 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 153,650 ​ $ 160,197 ​ $ — ​ $ — ​ $ 160,197 Derivatives - Interest rate contracts (c) ​ 6 ​ 6 ​ — ​ 6 ​ — Total assets ​ $ 153,656 ​ $ 160,203 ​ $ — ​ $ 6 ​ $ 160,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 142 ​ $ 142 ​ $ — ​ $ 142 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 906,228 ​ ​ 898,329 ​ ​ — ​ ​ — ​ ​ 898,329 Credit facilities ​ 218,490 ​ 213,661 ​ — ​ — ​ 213,661 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 16,583 ​ ​ 16,583 ​ ​ — ​ ​ — ​ ​ 16,583 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 3,263,152 ​ ​ 3,397,622 ​ ​ — ​ ​ — ​ ​ 3,397,622 Total liabilities ​ $ 4,731,595 ​ $ 4,853,337 ​ $ — ​ $ 142 ​ $ 4,853,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 1,018,665 ​ $ 1,018,665 ​ $ — ​ $ 1,018,665 ​ $ — (a) Balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) See Note 11, Derivatives and Hedging Activity . (d) See Note 7, Secured and Unsecured Debt, Net . (e) See Note 9, Noncontrolling Interests. There were no transfers into or out of any of the levels of the fair value hierarchy during the three months ended March 31, 2020. Financial Instruments Carried at Fair Value The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The fair values of interest rate options are determined using the market standard methodology of discounting the future expected cash receipts that would occur if variable interest rates rise above the strike rate of the caps. The variable interest rates used in the calculation of projected receipts on the cap are based on an expectation of future interest rates derived from observable market interest rate curves and volatilities. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2020 and December 31, 2019, the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. In conjunction with the FASB’s fair value measurement guidance, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership have a redemption feature and are marked to their redemption value. The redemption value is based on the fair value of the Company’s common stock at the redemption date, and therefore, is calculated based on the fair value of the Company’s common stock at the balance sheet date. Since the valuation is based on observable inputs such as quoted prices for similar instruments in active markets, redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership are classified as Level 2. Financial Instruments Not Carried at Fair Value At March 31, 2020 and December 31, 2019, the fair values of cash and cash equivalents, restricted cash, accounts receivable, prepaids, real estate taxes payable, accrued interest payable, security deposits and prepaid rent, distributions payable and accounts payable approximated their carrying values because of the short term nature of these instruments. The estimated fair values of other financial instruments, which includes notes receivable and debt instruments, are classified in Level 3 of the fair value hierarchy due to the significant unobservable inputs that are utilized in their respective valuations. We record impairment losses on long-lived assets used in operations when events and circumstances indicate that the assets might be impaired and the undiscounted cash flows estimated to be generated by the future operation and disposition of those assets are less than the net book value of those assets. Our cash flow estimates are based upon historical results adjusted to reflect our best estimate of future market and operating conditions and our estimated holding periods. The net book value of impaired assets is reduced to fair value. Our estimates of fair value represent our best estimate based upon Level 3 inputs such as industry trends and reference to market rates and transactions. We consider various factors to determine if a decrease in the value of our Investment in and advances to unconsolidated joint ventures, net After determining that an other-than-temporary decrease in the value of an equity method investment has occurred, we estimate the fair value of our investment by estimating the proceeds we would receive upon a hypothetical liquidation of the investment at the date of measurement. Inputs reflect management’s best estimate of what market participants would use in pricing the investment giving consideration to the terms of the joint venture agreement and the estimated discounted future cash flows to be generated from the underlying joint venture assets. The inputs and assumptions utilized to estimate the future cash flows of the underlying assets are based upon the Company’s evaluation of the economy, market trends, operating results, and other factors, including judgments regarding costs to complete any construction activities, lease up and occupancy rates, rental rates, inflation rates, capitalization rates utilized to estimate the projected cash flows at the disposition, and discount rates.

DERIVATIVES AND HEDGING ACTIVIT

DERIVATIVES AND HEDGING ACTIVITY	3 Months Ended
	Mar. 31, 2020
DERIVATIVES AND HEDGING ACTIVITY
DERIVATIVES AND HEDGING ACTIVITY	11. DERIVATIVES AND HEDGING ACTIVITY Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its debt funding and through the use of derivative financial instruments. Specifically, the Company may enter into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s investments and borrowings. Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps and caps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for an up-front premium. The changes in the fair value of derivatives designated and that qualify as cash flow hedges are recorded in Accumulated other comprehensive income/(loss), net Amounts reported in Accumulated other comprehensive income/(loss), net Interest expense As of March 31, 2020, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ Product ​ Instruments ​ Notional Interest rate swaps ​ 1 ​ $ 315,000 ​ Derivatives not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of GAAP. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings and resulted in no gain or loss for both the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Company had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps ​ 1 ​ $ 19,880 ​ Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheet The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ March 31, ​ December 31, ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ — ​ $ 6 ​ $ 3,075 ​ $ 142 ​ Tabular Disclosure of the Effect of Derivative Instruments on the Consolidated Statements of Operations The tables below present the effect of the Company’s derivative financial instruments on the Consolidated Statements of Operations for the three months ended March 31, 2020 and 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain/(Loss) Recognized in ​ ​ ​ ​ Gain/(Loss) Reclassified ​ Interest expense ​ ​ Unrealized holding gain/(loss) ​ from Accumulated OCI into ​ (Amount Excluded from ​ ​ Recognized in OCI ​ Interest expense ​ Effectiveness Testing) Derivatives in Cash Flow Hedging Relationships 2020 2019 2020 2019 2020 2019 Three Months Ended March 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ (2,917) ​ $ (2,210) ​ $ (357) ​ $ 945 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Total amount of Interest expense ​ $ 39,317 ​ $ 33,542 ​ The Company did not recognize any gain/(loss) in Interest income and other income/(expense), net Credit-risk-related Contingent Features The Company has agreements with its derivative counterparties that contain a provision where the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company’s default on the indebtedness. The Company has certain agreements with some of its derivative counterparties that contain a provision where, in the event of default by the Company or the counterparty, the right of setoff may be exercised. Any amount payable to one party by the other party may be reduced by its setoff against any amounts payable by the other party. Events that give rise to default by either party may include, but are not limited to, the failure to pay or deliver payment under the derivative agreement, the failure to comply with or perform under the derivative agreement, bankruptcy, a merger without assumption of the derivative agreement, or in a merger, a surviving entity’s creditworthiness is materially weaker than the original party to the derivative agreement. Tabular Disclosure of Offsetting Derivatives The Company has elected not to offset derivative positions on the consolidated financial statements. The tables below present the effect on its financial position had the Company made the election to offset its derivative positions as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount March 31, 2020 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 6 ​ $ — ​ $ 6 ​ $ (3) ​ $ — ​ $ 3 (a) Amounts reconcile to the aggregate fair value of derivative assets in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Liabilities ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount March 31, 2020 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — ​ $ — ​ $ 3,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 142 ​ $ — ​ $ 142 ​ $ (3) ​ $ — ​ $ 139 (a) Amounts reconcile to the aggregate fair value of derivative liabilities in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	3 Months Ended
	Mar. 31, 2020
EMPLOYEE BENEFIT PLANS
STOCK BASED COMPENSATION	12. STOCK BASED COMPENSATION The Company recognized stock based compensation expense, inclusive of awards granted to our non-employee directors, net of capitalization, of $6.8 million and $5.9 million during the three months ended March 31, 2020 and 2019, respectively.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2020
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	13. COMMITMENTS AND CONTINGENCIES Commitments Real Estate Commitments The following summarizes the Company’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Wholly-owned — under development 3 ​ $ 95,326 ​ $ 183,174 Wholly-owned — redevelopment 2 ​ ​ 17,660 ​ ​ 7,840 Joint ventures: ​ ​ Preferred equity investments 2 ​ ​ 34,647 (b) ​ 14,348 (c) Other investments ​ - ​ ​ 14,364 ​ ​ 23,700 (d) Total ​ $ 161,997 ​ $ 229,062 (a) Represents UDR’s investment as of March 31, 2020. (b) Represents UDR’s investment in Modera Lake Merritt and Thousand Oaks, which were under development as of March 31, 2020. (c) Represents UDR’s remaining commitment for Modera Lake Merritt and Thousand Oaks. (d) Represents UDR’s remaining commitment for other investment ventures. ​ Purchase Commitments In 2019, the Company entered into a contract to purchase a development land parcel located in King of Prussia, Pennsylvania for a purchase price of approximately $14.8 million. The Company made a $0.8 million deposit on the purchase, which is generally non-refundable other than due to a failure of closing conditions pursuant to the terms of the purchase agreement. The acquisition is expected to close in 2020, subject to completion of entitlement and customary closing conditions. Contingencies Litigation and Legal Matters The Company is subject to various legal proceedings and claims arising in the ordinary course of business. The Company cannot determine the ultimate liability with respect to such legal proceedings and claims at this time. The Company believes that such liability, to the extent not provided for through insurance or otherwise, will not have a material adverse effect on our financial condition, results of operations or cash flows.

REPORTABLE SEGMENTS

REPORTABLE SEGMENTS	3 Months Ended
	Mar. 31, 2020
REPORTABLE SEGMENTS
REPORTABLE SEGMENTS	14. REPORTABLE SEGMENTS GAAP guidance requires that segment disclosures present the measure(s) used by the Chief Operating Decision Maker to decide how to allocate resources and for purposes of assessing such segments’ performance. UDR’s Chief Operating Decision Maker is comprised of several members of its executive management team who use several generally accepted industry financial measures to assess the performance of the business for our reportable operating segments. UDR owns and operates multifamily apartment communities that generate rental and other property related income through the leasing of apartment homes to a diverse base of tenants. The primary financial measures for UDR’s apartment communities are rental income and net operating income (“NOI”). Rental income represents gross market rent less adjustments for concessions, vacancy loss and bad debt. NOI is defined as rental income less direct property rental expenses. Rental expenses include real estate taxes, insurance, personnel, utilities, repairs and maintenance, administrative and marketing. Excluded from NOI is property management expense, which is calculated as 2.875% of property revenue to cover the regional supervision and accounting costs related to consolidated property operations, and land rent. UDR’s Chief Operating Decision Maker utilizes NOI as the key measure of segment profit or loss. UDR’s two reportable segments are Same-Store Communities Non-Mature Communities/Other ● Same-Store Communities represent those communities acquired, developed, and stabilized prior to January 1, 2019 and held as of March 31, 2020. A comparison of operating results from the prior year is meaningful as these communities were owned and had stabilized occupancy and operating expenses as of the beginning of the prior period, there is no plan to conduct substantial redevelopment activities, and the community is not held for disposition within the current year. A community is considered to have stabilized occupancy once it achieves 90% occupancy for at least three consecutive months. ● Non-Mature Communities/Other represent those communities that do not meet the criteria to be included in Same-Store Communities , including, but not limited to, recently acquired, developed and redeveloped communities, and the non-apartment components of mixed use properties. Management evaluates the performance of each of our apartment communities on a Same-Store Community Non-Mature Community/Other criteria under GAAP as each of our apartment communities generally has similar economic characteristics, facilities, services, and tenants. Therefore, the Company’s reportable segments have been aggregated by geography in a manner identical to that which is provided to the Chief Operating Decision Maker. Revenue is measured based on consideration specified in contracts with customers. The Company recognizes revenue when it satisfies a performance obligation by providing the services specified in a contract to the customer. All revenues are from external customers and no single tenant or related group of tenants contributed 10% or more of UDR’s total revenues during the three months ended March 31, 2020 and 2019. ​ The following is a description of the principal streams from which the Company generates its revenue: Lease Revenue ​ Lease revenue related to leases is recognized on an accrual basis when due from residents or tenants in accordance with ASC 842, Leases ​ Lease revenue also includes all pass-through revenue from retail and residential leases and common area maintenance reimbursements from retail leases. These services represent non-lease components in a contract as the Company transfers a service to the lessee other than the right to use the underlying asset. The Company has elected the practical expedient under the leasing standard to not separate lease and non-lease components from its resident and retail lease contracts as the timing and pattern of revenue recognition for the non-lease component and related lease component are the same and the combined single lease component would be classified as an operating lease. ​ Other Revenue ​ ​ Joint venture management and other fees ​ The Joint venture management and other fees Joint venture management and other fees ​ The following table details rental income and NOI for UDR’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (a) ​ 2020 2019 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 102,616 ​ $ 98,633 Mid-Atlantic Region ​ 56,085 ​ 54,300 Northeast Region ​ 30,942 ​ 30,193 Southeast Region ​ 30,677 ​ 29,531 Southwest Region ​ 16,626 ​ 16,077 Non-Mature Communities/Other ​ 74,676 ​ 30,169 Total segment and consolidated lease revenue ​ $ 311,622 ​ $ 258,903 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 2,774 ​ $ 3,076 Mid-Atlantic Region ​ 1,573 ​ 2,002 Northeast Region ​ 501 ​ 629 Southeast Region ​ 1,429 ​ 1,790 Southwest Region ​ 590 ​ 763 Non-Mature Communities/Other ​ 1,604 ​ 759 Total segment and consolidated other revenue ​ $ 8,471 ​ $ 9,019 ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 105,390 ​ $ 101,709 Mid-Atlantic Region ​ 57,658 ​ 56,302 Northeast Region ​ 31,443 ​ 30,822 Southeast Region ​ 32,106 ​ 31,321 Southwest Region ​ 17,216 ​ 16,840 Non-Mature Communities/Other ​ 76,280 ​ 30,928 Total segment and consolidated rental income ​ $ 320,093 ​ $ 267,922 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ Same-Store Communities (a) ​ ​ West Region ​ $ 79,823 ​ $ 76,984 Mid-Atlantic Region ​ 40,377 ​ 39,179 Northeast Region ​ 20,614 ​ 20,977 Southeast Region ​ 22,617 ​ 22,010 Southwest Region ​ 11,056 ​ 10,328 Non-Mature Communities/Other ​ 50,978 ​ 20,205 Total segment and consolidated NOI ​ 225,465 ​ 189,683 Reconciling items: ​ ​ Joint venture management and other fees ​ 1,388 ​ 2,751 Property management ​ (9,203) ​ (7,703) Other operating expenses ​ (4,966) ​ (5,646) Real estate depreciation and amortization ​ (155,476) ​ (112,468) General and administrative ​ (14,978) ​ (12,467) Casualty-related (charges)/recoveries, net ​ (1,251) ​ — Other depreciation and amortization ​ (2,025) ​ (1,656) Income/(loss) from unconsolidated entities ​ 3,367 ​ 49 Interest expense ​ (39,317) ​ (33,542) Interest income and other income/(expense), net ​ 2,700 ​ 9,813 Tax (provision)/benefit, net ​ (164) ​ (2,212) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) Net income/(loss) attributable to UDR, Inc. ​ $ 5,221 ​ $ 24,503 (a) Same-Store Community population consisted of 37,910 apartment homes. ​ The following table details the assets of UDR’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 3,704,480 ​ $ 3,696,544 Mid-Atlantic Region ​ 2,356,688 ​ 2,350,341 Northeast Region ​ 1,501,767 ​ 1,500,597 Southeast Region ​ 810,984 ​ 806,830 Southwest Region ​ 603,082 ​ 600,350 Non-Mature Communities/Other ​ 3,840,997 ​ 3,647,439 Total segment assets ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Total segment assets — net book value ​ 8,545,527 ​ 8,470,748 Reconciling items: ​ ​ Cash and cash equivalents ​ 980 ​ 8,106 Restricted cash ​ 21,949 ​ 25,185 Notes receivable, net ​ 151,543 ​ 153,650 Investment in and advances to unconsolidated joint ventures, net ​ 588,395 ​ 588,262 Operating lease right-of-use assets ​ ​ 203,410 ​ ​ 204,225 Other assets ​ 179,301 ​ 186,296 Total consolidated assets ​ $ 9,691,105 ​ $ 9,636,472 (a) Same-Store Community population consisted of 37,910 apartment homes. ​ Markets included in the above geographic segments are as follows: i. West Region — Orange County, San Francisco, Seattle, Los Angeles, Monterey Peninsula, Other Southern California and Portland ii. Mid-Atlantic Region — Metropolitan D.C., Richmond and Baltimore iii. Northeast Region — New York and Boston iv. Southeast Region — Orlando, Nashville, Tampa and Other Florida v. Southwest Region — Dallas, Austin and Denver

SUBSEQUENT EVENT

SUBSEQUENT EVENT	3 Months Ended
	Mar. 31, 2020
SUBSEQUENT EVENT
Subsequent Event	15. Subsequent Event ​ The Company is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business. The extent of the pandemic’s effect on our operational and financial performance will depend on future developments, including the duration, spread and intensity of the pandemic and the duration of government measures to mitigate the pandemic, all of which are uncertain and difficult to predict. Although the effect on our results of operations and cash flows through the date of issuance of our financial statements was not material, given the uncertainty, we cannot predict the effect on future periods, but the adverse impact on the Company's future financial condition, results of operations and cash flows could be material ​ ​

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2020
SIGNIFICANT ACCOUNTING POLICIES
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, basis through a cumulative-effect adjustment to retained earnings of approximately $2.2 million on that date, which was primarily associated with our notes receivable. The Company concluded the cumulative effect was not material to our consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848)
Principles of Consolidation	Principles of Consolidation The Company accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Company first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Company consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest.
Real Estate Sales Gain Recognition	Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Company generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Company will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Company sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Company will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Company will record a full gain or loss in the period the property is contributed. ​ To the extent that the Company acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Company will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Company will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Company will not recognize a gain or loss on consolidation of a property.
Allowance for Credit Losses	Allowance for Credit Losses The Company accounts for allowance for credit losses under the current expected credit loss (“CECL”) impairment model for its financial assets, including trade and other receivables, held-to-maturity debt securities, loans and other financial instruments, and presents the net amount of the financial instrument expected to be collected. The CECL impairment model excludes operating lease receivables. The CECL impairment model requires an estimate of expected credit losses, measured over the contractual life of an instrument, that considers forecasts of future economic conditions in addition to information about past events and current conditions. Based on this model, we analyze the following criteria, as applicable in developing allowances for credit losses: historical loss information, the borrower’s ability to make scheduled payments, the remaining time to maturity, the value of underlying collateral, projected future performance of the borrower and macroeconomic trends. ​ The Company measures credit losses of financial assets on a collective (pool) basis when similar risk characteristics exist. If the Company determines that a financial asset does not share risk characteristics with its other financial assets, the Company evaluates the financial asset for expected credit losses on an individual basis. Allowance for credit losses are recorded as a direct reduction from an asset’s amortized cost basis. Credit losses and recoveries are recorded in Interest income and other income/(expense), net ​ The Company has made the optional election provided by the standard not to measure allowance for credit losses for accrued interest receivables as the Company writes off any uncollectible accrued interest receivables in a timely manner. The Company periodically evaluates the collectability of its accrued interest receivables. A write-off is recorded when the Company concludes that all or a portion of its accrued interest receivable balance is no longer collectible.
Notes Receivable	Notes Receivable Notes receivable relate to financing arrangements which are typically secured by real estate, real estate related projects or other assets. Certain of the loans we extend may include characteristics such as options to purchase the project within a specific time window following expected project completion. These characteristics can cause the loans to fall under the definition of a VIE, and thus trigger consolidation consideration. We consider the facts and circumstances pertinent to each loan, including the relative amount of financing we are contributing to the overall project cost, decision making rights or control we hold, and our rights to expected residual gains or our obligations to absorb expected residual losses from the project. If we are deemed to be the primary beneficiary of a VIE due to holding a controlling financial interest, the majority of decision making control, or by other means, consolidation of the VIE would be required. The Company has concluded that it is not the primary beneficiary of the borrowing entities which were deemed to be VIEs. Additionally, we analyze each loan arrangement that involves real estate development to consider whether the loan qualifies for accounting as a loan or as an investment in a real estate development project. The Company has evaluated its real estate loans, where appropriate, for accounting treatment as loans versus real estate development projects, as required by ASC 310-10. For each loan, the Company has concluded that the characteristics and the facts and circumstances indicate that loan accounting treatment is appropriate. The following table summarizes our Notes receivable, net dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due April 2020 (a) 12.00 % $ 20,000 ​ $ 20,000 Note due October 2020 (b) 8.00 % — ​ 2,250 Note due October 2022 (c) 4.75 % 115,000 ​ 115,000 Note due January 2023 (d) ​ 10.00 % ​ 17,300 ​ ​ 16,400 Notes Receivable ​ ​ ​ ​ 152,300 ​ ​ 153,650 Allowance for credit losses ​ ​ ​ ​ (757) ​ ​ — Total notes receivable, net ​ $ 151,543 ​ $ 153,650 (a) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, all of which has been funded. The note is secured by a parcel of land and related land improvements. Interest payments up to December 2019 are due when the loan matures and interest payments after December 2019 are due monthly. In April 2020, the terms of the secured note were amended to extend the term to May 30, 2022, to adjust the interest rate to 8.0% and to add some covenants of the Borrower. (b) In March 2020, the Company entered into a purchase agreement to acquire all of the unaffiliated third party’s intellectual property in exchange for cancellation of the secured note and accrued interest. All property acquired was recorded in Other assets on the Consolidated Balance Sheets. (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $115.0 million, all of which has been funded. Interest payments are due when the loan matures. The note is secured by a first priority deed of trust on an under construction 259 apartment home operating community in Bellevue, Washington, which is expected to be completed in 2020. When the note was funded, the Company also entered into a purchase option agreement and paid a deposit of $10.0 million, which gives the Company the option to acquire the community at a fixed price of $170.0 million. The purchase option must be exercised within 30 days following the date the temporary certificate of occupancy for the residential portion of the project is issued. The deposit is generally nonrefundable other than due to a failure of closing conditions pursuant to the terms of the agreement. If the Company does not exercise the purchase option, or if the Company exercises and fails to close the purchase other than due to seller’s failure or other breaches in the purchase option agreement, per the terms of the agreement, the note will be modified to extend the maturity date to 10 years following the date the temporary certificate of occupancy is issued. Upon modification, the loan will be interest only for the first three years and after such date payments will be based on a 30-year amortization schedule. (d) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, of which $17.3 million has been funded, including $0.9 million funded during the three months ended March 31, 2020. Interest payments are due monthly. The note matures at the earliest of the following: (a) the closing of any private or public capital raising in the amount of $5.0 million or greater; (b) an acquisition; (c) acceleration in the event of default; or (d) January 2023. During 2020, the terms of this secured note were amended to increase the aggregate commitment from $16.4 million to $20.0 million, to extend the maturity date of the note to January 2023 and for the April 2020 through July 2020 interest payments to be deferred and paid when the note matures The Company recognized $2.6 million and $1.1 million of interest income for the notes receivable described above during the three months ended March 31, 2020 and 2019, respectively, none of which was related party interest. Interest income is included in Interest income and other income/(expense), net
Comprehensive Income/(Loss)	Comprehensive Income/(Loss) Comprehensive income/(loss), which is defined as the change in equity during each period from transactions and other events and circumstances from nonowner sources, including all changes in equity during a period except for those resulting from investments by or distributions to stockholders, is displayed in the accompanying Consolidated Statements of Comprehensive Income/(Loss). For the three months ended March 31, 2020 and 2019, the Company’s other comprehensive income/(loss) consisted of the gain/(loss) on derivative instruments that are designated as and qualify as cash flow hedges, (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) into earnings, and the allocation of other comprehensive income/(loss) to noncontrolling interests. The (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) is included in Interest expense Derivatives and Hedging Activity,
Income Taxes	Income Taxes Due to the structure of the Company as a REIT and the nature of the operations for the operating properties, no provision for federal income taxes has been provided for at UDR. Historically, the Company has generally incurred only state and local excise and franchise taxes. UDR has elected for certain consolidated subsidiaries to be treated as taxable REIT subsidiaries (“TRS”). Income taxes for our TRS are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rate is recognized in earnings in the period of the enactment date. The Company’s deferred tax assets/(liabilities) are generally the result of differing depreciable lives on capitalized assets, temporary differences between book and tax basis of assets and liabilities and timing of expense recognition for certain accrued liabilities. As of March 31, 2020 and December 31, 2019, UDR’s net deferred tax asset/(liability) was $(1.4) million and $(1.6) million, respectively. GAAP defines a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. GAAP also provides guidance on derecognition, classification, interest and penalties, accounting for interim periods, disclosure and transition. The Company recognizes its tax positions and evaluates them using a two-step process. First, UDR determines whether a tax position is more likely than not (greater than 50 percent probability) to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. Second, the Company will determine the amount of benefit to recognize and record the amount that is more likely than not to be realized upon ultimate settlement. The Company invests in assets that qualify for federal investment tax credits (“ITC”) through our TRS. An ITC reduces federal income taxes payable when qualifying depreciable property is acquired. The ITC is determined as a percentage of cost of the assets. The Company accounts for ITCs under the deferral method, under which the tax benefit from the ITC is deferred and amortized as a tax benefit into Tax (provision)/benefit, net Accounts payable, accrued expenses and other liabilities UDR had no material unrecognized tax benefit, accrued interest or penalties at March 31, 2020. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2016 through 2018 remain open to examination by tax jurisdictions to which we are subject. When applicable, UDR recognizes interest and/or penalties related to uncertain tax positions in Tax (provision)/benefit, net
Forward Sales Agreements	Forward Sales Agreements ​ The Company utilizes forward sales agreements for the future issuance of its common stock. When the Company enters into a forward sales agreement, the contract requires the Company to sell its shares to a counterparty at a predetermined price at a future date. The net sales price and proceeds attained by the Company will be determined on the dates of settlement, with adjustments during the term of the contract for the Company’s anticipated dividends as well as for a daily interest factor that varies with changes in the federal funds rate. The Company generally has the ability to determine the dates and method of settlement (i.e., gross physical settlement, net share settlement or cash settlement), subject to certain conditions and the right of the counterparty to accelerate settlement under certain circumstances. ​ The Company accounts for the shares of common stock reserved for issuance upon settlement as equity in accordance with ASC 815-40, Contracts in Entity's Own Equity ​ The guidance establishes a two-step process for evaluating whether an equity-linked financial instrument is considered indexed to its own stock, first, evaluating the instrument’s contingent exercise provisions and second, evaluating the instrument’s settlement provisions. When entering into forward sales agreements, we determined that (i) none of the agreement’s exercise contingencies are based on observable markets or indices besides those related to the market for our own stock price; and (ii) none of the settlement provisions preclude the agreements from being indexed to our own stock. ​ Before the issuance of shares of common stock, upon physical or net share settlement of the forward sales agreements, the Company expects that the shares issuable upon settlement of the forward sales agreements will be reflected in its diluted income/(loss) per share calculations using the treasury stock method. Under this method, the number of shares of common stock used in calculating diluted income/(loss) per share is deemed to be increased by the excess, if any, of the number of shares of common stock that would be issued upon full physical settlement of the forward sales agreements over the number of shares of common stock that could be purchased by the Company in the open market (based on the average market price during the period) using the proceeds receivable upon full physical settlement (based on the adjusted forward sale price at the end of the reporting period). When the Company physically or net share settles any forward sales agreement, the delivery of shares of common stock would result in an increase in the number of weighted average common shares outstanding and dilution to basic income/(loss) per share. (See Note 8, Income/(Loss) per Share

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	3 Months Ended
	Mar. 31, 2020
SIGNIFICANT ACCOUNTING POLICIES
Summary of notes receivable, net	The following table summarizes our Notes receivable, net dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due April 2020 (a) 12.00 % $ 20,000 ​ $ 20,000 Note due October 2020 (b) 8.00 % — ​ 2,250 Note due October 2022 (c) 4.75 % 115,000 ​ 115,000 Note due January 2023 (d) ​ 10.00 % ​ 17,300 ​ ​ 16,400 Notes Receivable ​ ​ ​ ​ 152,300 ​ ​ 153,650 Allowance for credit losses ​ ​ ​ ​ (757) ​ ​ — Total notes receivable, net ​ $ 151,543 ​ $ 153,650 (a) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, all of which has been funded. The note is secured by a parcel of land and related land improvements. Interest payments up to December 2019 are due when the loan matures and interest payments after December 2019 are due monthly. In April 2020, the terms of the secured note were amended to extend the term to May 30, 2022, to adjust the interest rate to 8.0% and to add some covenants of the Borrower. (b) In March 2020, the Company entered into a purchase agreement to acquire all of the unaffiliated third party’s intellectual property in exchange for cancellation of the secured note and accrued interest. All property acquired was recorded in Other assets on the Consolidated Balance Sheets. (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $115.0 million, all of which has been funded. Interest payments are due when the loan matures. The note is secured by a first priority deed of trust on an under construction 259 apartment home operating community in Bellevue, Washington, which is expected to be completed in 2020. When the note was funded, the Company also entered into a purchase option agreement and paid a deposit of $10.0 million, which gives the Company the option to acquire the community at a fixed price of $170.0 million. The purchase option must be exercised within 30 days following the date the temporary certificate of occupancy for the residential portion of the project is issued. The deposit is generally nonrefundable other than due to a failure of closing conditions pursuant to the terms of the agreement. If the Company does not exercise the purchase option, or if the Company exercises and fails to close the purchase other than due to seller’s failure or other breaches in the purchase option agreement, per the terms of the agreement, the note will be modified to extend the maturity date to 10 years following the date the temporary certificate of occupancy is issued. Upon modification, the loan will be interest only for the first three years and after such date payments will be based on a 30-year amortization schedule. (d) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, of which $17.3 million has been funded, including $0.9 million funded during the three months ended March 31, 2020. Interest payments are due monthly. The note matures at the earliest of the following: (a) the closing of any private or public capital raising in the amount of $5.0 million or greater; (b) an acquisition; (c) acceleration in the event of default; or (d) January 2023. During 2020, the terms of this secured note were amended to increase the aggregate commitment from $16.4 million to $20.0 million, to extend the maturity date of the note to January 2023 and for the April 2020 through July 2020 interest payments to be deferred and paid when the note matures

REAL ESTATE OWNED (Tables)

REAL ESTATE OWNED (Tables)	3 Months Ended
	Mar. 31, 2020
REAL ESTATE OWNED
Summary of carrying amounts for real estate owned (at cost)	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 2,163,055 ​ $ 2,164,032 Depreciable property — held and used: ​ ​ Land improvements ​ 225,850 ​ 224,964 Building, improvements, and furniture, fixtures and equipment ​ 10,178,547 ​ 10,102,758 Real estate intangible assets ​ ​ 40,570 ​ ​ 40,570 Under development: ​ ​ Land and land improvements ​ 29,226 ​ 29,226 Building, improvements, and furniture, fixtures and equipment ​ 66,100 ​ 40,551 Real estate held for disposition: ​ ​ Land and land improvements ​ 16,245 ​ — Building, improvements, and furniture, fixtures and equipment ​ 98,405 ​ — Real estate owned ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Real estate owned, net ​ $ 8,545,527 ​ $ 8,470,748

JOINT VENTURES AND PARTNERSHI_2

JOINT VENTURES AND PARTNERSHIPS (Tables)	3 Months Ended
	Mar. 31, 2020
JOINT VENTURES AND PARTNERSHIPS
Schedule of unconsolidated joint ventures and partnerships	The following table summarizes the Company’s investment in and advances to unconsolidated joint ventures and partnerships, net, which are accounted for under the equity method of accounting as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Number of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating ​ Apartment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ Communities ​ Homes ​ Investment at ​ UDR’s Ownership Interest ​ ​ Three Months Ended ​ Location of March 31, March 31, March 31, December 31, ​ March 31, ​ December 31, ​ March 31, Joint Venture Properties 2020 2020 2020 2019 ​ 2020 ​ 2019 ​ 2020 2019 Operating: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR/MetLife I ​ Los Angeles, CA ​ 1 ​ 150 ​ $ 28,570 ​ $ 28,812 ​ 50.0 % ​ 50.0 % ​ $ (454) ​ $ (576) UDR/MetLife II Various 7 1,250 ​ 150,652 ​ 150,893 ​ 50.0 % ​ 50.0 % ​ ​ (91) ​ ​ 434 Other UDR/MetLife Joint Ventures Various 5 1,437 ​ 94,109 ​ 98,441 ​ 50.6 % ​ 50.6 % ​ ​ (1,811) ​ ​ (1,777) West Coast Development Joint Ventures ​ Los Angeles, CA ​ 1 ​ 293 ​ ​ 34,943 ​ ​ 34,907 ​ 47.0 % ​ 47.0 % ​ ​ (77) ​ ​ (149) Sold Joint Ventures ​ ​ ​ ​ ​ ​ ​ ​ — ​ ​ — ​ — % ​ — % ​ ​ — ​ ​ (1,819) Investment in and advances to unconsolidated joint ventures, net, before preferred equity investments and other investments ​ $ 308,274 ​ $ 313,053 ​ ​ ​ ​ $ (2,433) ​ $ (3,887) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment at ​ Three Months Ended ​ Developer Capital Program ​ ​ Years To ​ UDR March 31, December 31, March 31, ​ and Other Investments (a) Location Rate Maturity ​ Commitment (b) 2020 2019 2020 2019 ​ Preferred equity investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ West Coast Development Joint Ventures (c) Hillsboro, OR 6.5 % N/A ​ $ — ​ $ — ​ $ 17,064 ​ $ (46) ​ $ (161) ​ 1532 Harrison ​ San Francisco, CA ​ 11.0 % 2.3 ​ ​ 24,645 ​ ​ 31,426 ​ ​ 30,585 ​ ​ 836 ​ ​ 748 ​ 1200 Broadway (d) ​ Nashville, TN ​ 8.0 % 2.5 ​ ​ 55,558 ​ ​ 65,254 ​ ​ 63,958 ​ ​ 1,281 ​ ​ 1,169 ​ Junction ​ Santa Monica, CA ​ 12.0 % 2.3 ​ ​ 8,800 ​ ​ 10,693 ​ ​ 10,379 ​ ​ 314 ​ ​ 275 ​ 1300 Fairmount (d) ​ Philadelphia, PA ​ Variable ​ 3.4 ​ ​ 51,393 ​ ​ 55,840 ​ ​ 51,215 ​ ​ 1,166 ​ ​ 275 ​ Essex ​ Orlando, FL ​ 12.5 % 3.4 ​ ​ 12,886 ​ ​ 15,270 ​ ​ 14,804 ​ ​ 466 ​ ​ 332 ​ Modera Lake Merritt (d) ​ Oakland, CA ​ 9.0 % 4.0 ​ ​ 27,250 ​ ​ 28,653 ​ ​ 22,653 ​ ​ 574 ​ ​ — ​ Thousand Oaks (e) ​ Thousand Oaks, CA ​ 9.0 % 4.9 ​ ​ 20,059 ​ ​ 5,994 ​ ​ — ​ ​ 24 ​ ​ — ​ Other investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Portals ​ Washington, D.C. ​ 11.0 % 1.2 ​ ​ 38,559 ​ ​ 49,323 ​ ​ 48,181 ​ ​ 1,335 ​ ​ 1,173 ​ Other investment ventures ​ N/A ​ N/A ​ N/A ​ $ 34,500 ​ ​ 14,364 ​ ​ 13,598 ​ ​ (150) ​ ​ 125 ​ Total Developer Capital Program and Other Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 276,817 ​ ​ 272,437 ​ ​ 5,800 ​ ​ 3,936 ​ Total Joint Ventures and Developer Capital Program Investments, net (f) ​ ​ ​ ​ $ 585,091 ​ $ 585,490 ​ $ 3,367 $ 49 ​ (a) The Developer Capital Program is the program through which the Company makes investments, including preferred equity investments, mezzanine loans or other structured investments that may receive a fixed yield on the investment and may include provisions pursuant to which the Company participates in the increase in value of the property upon monetization of the applicable property and/or holds fixed price purchase options. (b) Represents UDR’s maximum funding commitment only and therefore excludes other activity such as income from investments. (c) In January 2020, the Company increased its ownership interest from 49% to 100% in the 276 apartment home operating community located in Hillsboro, Oregon, for a cash purchase price of approximately $21.6 million. As a result, the Company consolidated the operating community and it is no longer accounted for as a preferred equity investment in an unconsolidated joint venture (see Note 3, Real Estate Owned ). In connection with the purchase, the Company repaid the joint venture’s construction loan of approximately $35.6 million. (d) The Company’s preferred equity investment receives a variable percentage of the value created from the project upon a capital or liquidating event. (e) In February 2020, the Company entered into a joint venture agreement with an unaffiliated joint venture partner to develop and operate a 142 apartment home community in Thousand Oaks, CA. The Company’s preferred equity investment of up to $20.1 million earns a preferred return of 9.0% per annum and receives a variable percentage of the value created from the project upon a capital or liquidating event. The unaffiliated joint venture partner is the managing member of the joint venture and the developer of the community. The Company has concluded that it does not control the joint venture and, therefore, accounts for it under the equity method of accounting. (f) As of March 31, 2020, the Company’s negative investment in 13 th and Market Properties LLC of $3.3 million is included in Other UDR/MetLife Joint Ventures in the table above and recorded in Accounts payable, accrued expenses, and other liabilities on the Consolidated Balance Sheet.
Combined summary of balance sheets relating to unconsolidated joint ventures and partnerships	Combined summary balance sheets relating to the unconsolidated joint ventures’ and partnerships’ (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,868,502 $ 1,901,081 Cash and cash equivalents ​ 32,486 ​ 29,823 Other assets ​ ​ 180,893 ​ 172,941 Total assets $ 2,081,881 $ 2,103,845 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,136,306 ​ $ 1,148,048 Accounts payable and accrued liabilities ​ ​ 50,262 ​ ​ 55,114 Total liabilities ​ 1,186,568 ​ 1,203,162 Total equity $ 895,313 $ 900,683
Schedule of combined financial information relating to unconsolidated joint ventures and partnerships operations (not just proportionate share)	Combined summary financial information relating to the unconsolidated joint ventures’ and partnerships’ operations (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenues $ 41,314 $ 81,532 Property operating expenses ​ 15,297 ​ 30,312 Real estate depreciation and amortization ​ 16,243 ​ 29,580 Operating income/(loss) ​ 9,774 ​ ​ 21,640 Interest expense ​ (10,347) ​ (21,924) Net unrealized gain/(loss) on held investments ​ ​ — ​ ​ 1,522 Other income/(loss) ​ ​ (8) ​ ​ 103 Net income/(loss) $ (581) $ 1,341 (1)

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2020
LEASES
Lessee - Future minimum lease payments and total operating lease liabilities	Future minimum lease payments and total operating lease liabilities from our ground leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2020 ​ $ 9,330 2021 ​ ​ 12,442 2022 ​ ​ 12,442 2023 ​ ​ 12,442 2024 ​ ​ 12,442 Thereafter ​ ​ 455,221 Total future minimum lease payments (undiscounted) ​ ​ 514,319 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) Total operating lease liabilities (discounted) ​ $ 197,829
Lessee - components of operating lease expenses	The components of operating lease expenses were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2020 ​ 2019 Lease expense: ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,170 ​ $ 2,159 Variable lease expense (a) ​ ​ 43 ​ ​ 139 Total operating lease expense (b)(c) ​ $ 3,213 ​ $ 2,298 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.8 million and $0.7 million, respectively, and for the three months ended March 31, 2019 Operating lease right-of-use assets and Operating lease liabilities amortized by $0.2 million and $0.1 million, respectively. The Company recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization. ​
Lessor - Future minimum lease payments	Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 16,849 2021 ​ ​ 22,487 2022 ​ ​ 20,781 2023 ​ ​ 19,317 2024 ​ ​ 17,594 Thereafter ​ ​ 81,662 Total future minimum lease payments (a) ​ $ 178,690 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months or less.

SECURED AND UNSECURED DEBT, N_2

SECURED AND UNSECURED DEBT, NET (Tables)	3 Months Ended
	Mar. 31, 2020
Unsecured Debt
Schedule of debt instruments	The following is a summary of our secured and unsecured debt at March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ March 31, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2020 2019 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 883,249 ​ $ 884,869 3.61 % 5.9 15 Credit facilities (b) ​ 203,429 ​ 204,590 4.90 % 2.8 4 Deferred financing costs and other non-cash adjustments ​ 30,585 ​ 33,046 Total fixed rate secured debt, net ​ 1,117,263 ​ 1,122,505 3.85 % 5.3 19 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, net ​ 1,144,201 ​ 1,149,441 3.80 % 5.5 20 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2023 (d) (m) ​ 50,000 ​ — 1.75 % 2.8 Borrowings outstanding under unsecured commercial paper program due April 2020 (e) (m) (n) ​ ​ 215,000 ​ ​ 300,000 ​ 1.58 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2021 ​ 24,797 ​ 16,583 1.82 % 0.8 Term Loan due September 2023 (d) (m) ​ 35,000 ​ 35,000 2.48 % 3.5 Fixed Rate Debt ​ ​ 1.93% Term Loan due September 2023 (d) (m) ​ ​ 315,000 ​ 315,000 1.93 % 3.5 ​ ​ 3.75% Medium-Term Notes due July 2024 (net of discounts of $443 and $470, respectively) (g) (m) ​ 299,557 ​ 299,530 3.75 % 4.3 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 4.5 4.00% Medium-Term Notes due October 2025 (net of discounts of $379 and $396, respectively) (h) (m) ​ 299,621 ​ 299,604 4.00 % 5.5 2.95% Medium-Term Notes due September 2026 (m) ​ 300,000 ​ 300,000 2.95 % 6.4 3.50% Medium-Term Notes due July 2027 (net of discounts of $511 and $529, respectively) (m) ​ ​ 299,489 ​ ​ 299,471 ​ 3.50 % 7.3 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $924 and $954, respectively) (m) ​ ​ 299,076 ​ ​ 299,046 ​ 3.50 % 7.8 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $5 and $5, respectively) (i) (m) ​ ​ 299,995 ​ ​ 299,995 ​ 4.40 % 8.8 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $13,442 and $2,281, respectively) (j) (m) ​ ​ 613,442 ​ ​ 402,281 ​ 3.20 % 9.8 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of discounts of $1,099 and $1,123, respectively) (k) (m) ​ ​ 398,901 ​ ​ 398,877 ​ 3.00 % 11.4 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $1,287 and $1,309, respectively) (l) (m) ​ ​ 298,713 ​ ​ 298,691 ​ 3.10 % 14.6 ​ ​ Other ​ 12 ​ 13 Deferred financing costs ​ (23,310) ​ (21,652) Total Unsecured Debt, net ​ 3,740,937 ​ 3,558,083 3.29 % 7.5 Total Debt, net ​ $ 4,885,138 ​ $ 4,707,524 3.28 % 7.1
Schedule of aggregate maturities, including amortizing principal payments of secured and unsecured debt	The aggregate maturities, including amortizing principal payments on secured and unsecured debt, of total debt for the next ten calendar years subsequent to March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2020 ​ $ 112,592 ​ $ — ​ $ 112,592 ​ $ 215,000 (a) $ 327,592 2021 ​ ​ 8,763 ​ ​ — ​ ​ 8,763 ​ ​ 24,797 ​ ​ 33,560 2022 ​ 9,159 ​ — ​ 9,159 ​ — ​ 9,159 2023 ​ 295,965 ​ — ​ 295,965 ​ 400,000 ​ 695,965 2024 ​ 95,280 ​ — ​ 95,280 ​ 315,644 ​ 410,924 2025 ​ 173,189 ​ — ​ 173,189 ​ 300,000 ​ 473,189 2026 ​ 51,070 ​ — ​ 51,070 ​ 300,000 ​ 351,070 2027 ​ 1,111 ​ — ​ 1,111 ​ 300,000 ​ 301,111 2028 ​ 122,465 ​ — ​ 122,465 ​ 300,000 ​ 422,465 2029 ​ 144,584 ​ — ​ 144,584 ​ 300,000 ​ 444,584 Thereafter ​ 72,500 ​ 27,000 ​ 99,500 ​ 1,300,000 ​ 1,399,500 Subtotal ​ 1,086,678 ​ 27,000 ​ 1,113,678 ​ 3,755,441 ​ 4,869,119 Non-cash (b) ​ 30,585 ​ (62) ​ 30,523 ​ (14,504) ​ 16,019 Total ​ $ 1,117,263 ​ $ 26,938 ​ $ 1,144,201 ​ $ 3,740,937 ​ $ 4,885,138 (a) All unsecured debt due in the remainder of 2020 is related to the Company’s commercial paper program. (b) Includes the unamortized balance of fair market value adjustments, premiums/discounts and deferred financing costs . The Company amortized $1.0 million and $1.0 million, respectively, during the three months ended March 31, 2020 and 2019, of deferred financing costs into Interest expense.
Commercial Paper
Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the unsecured commercial paper program at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total unsecured commercial paper program $ 500,000 ​ $ 500,000 ​ Borrowings outstanding at end of period ​ 215,000 ​ 300,000 ​ Weighted average daily borrowings during the period ended ​ 346,978 ​ 173,353 ​ Maximum daily borrowings during the period ended ​ 500,000 ​ 435,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.5 % Interest rate at end of the period ​ 1.6 % 2.0 %
Revolving Credit Facility
Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the Revolving Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 2019 ​ Total revolving credit facility ​ $ 1,100,000 ​ $ 1,100,000 ​ Borrowings outstanding at end of period (1) ​ 50,000 ​ — ​ Weighted average daily borrowings during the period ended ​ 11,538 ​ 55 ​ Maximum daily borrowings during the period ended ​ 50,000 ​ 20,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.6 % Interest rate at end of the period ​ 1.8 % — % (1) Excludes $2.5 million and $2.9 million of letters of credit at March 31, 2020 and December 31, 2019, respectively .
Unsecured Working Capital Credit Facility
Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the Working Capital Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total working capital credit facility ​ $ 75,000 ​ $ 75,000 ​ Borrowings outstanding at end of period ​ 24,797 ​ 16,583 ​ Weighted average daily borrowings during the period ended ​ 25,212 ​ 23,487 ​ Maximum daily borrowings during the period ended ​ 46,419 ​ 66,170 ​ Weighted average interest rate during the period ended ​ 2.2 % 3.1 % Interest rate at end of the period ​ 1.8 % 2.6 %

INCOME_(LOSS) PER SHARE (Tables

INCOME/(LOSS) PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2020
INCOME/(LOSS) PER SHARE
Computation of basic and diluted income/(loss) per share	The following table sets forth the computation of basic and diluted income/(loss) per share for the periods presented (dollars and shares in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 ​ Numerator for income/(loss) per share: ​ ​ ​ ​ ​ ​ Net income/(loss) ​ $ 5,540 ​ $ 26,602 ​ Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) ​ Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) ​ Net income/(loss) attributable to UDR, Inc. ​ 5,221 ​ 24,503 ​ Distributions to preferred stockholders — Series E (Convertible) ​ (1,066) ​ (1,011) ​ Income/(loss) attributable to common stockholders - basic and diluted ​ $ 4,155 ​ $ 23,492 ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for income/(loss) per share: ​ ​ ​ Weighted average common shares outstanding ​ 294,731 ​ 277,297 ​ Non-vested restricted stock awards ​ (274) ​ (295) ​ Denominator for basic income/(loss) per share ​ 294,457 ​ 277,002 ​ Incremental shares issuable from assumed conversion of unvested LTIP Units and unvested restricted stock ​ 703 ​ 555 ​ Denominator for diluted income/(loss) per share ​ 295,160 ​ 277,557 ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) per weighted average common share: ​ ​ ​ Basic ​ $ 0.01 ​ $ 0.08 ​ Diluted ​ $ 0.01 ​ $ 0.08 ​
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table sets forth the additional shares of common stock issuable, by equity instrument, if such equity instrument were converted to or redeemed for common stock for each of the three months ended March 31, 2020 and 2019 (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2020 ​ 2019 ​ OP/DownREIT Units 22,228 24,280 Convertible preferred stock 3,011 3,011 Unvested LTIP Units and unvested restricted stock 703 555

NONCONTROLLING INTERESTS (Table

NONCONTROLLING INTERESTS (Tables)	3 Months Ended
	Mar. 31, 2020
NONCONTROLLING INTERESTS
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	The following table sets forth redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership for the following period ( dollars in thousands ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, December 31, 2019 $ 1,018,665 ​ Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (205,713) ​ Conversion of OP Units/DownREIT Units to Common Stock ​ (7,830) ​ Net income/(loss) attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ 313 ​ Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (9,182) ​ Vesting of Long-Term Incentive Plan Units ​ ​ 23,018 ​ Allocation of other comprehensive income/(loss) ​ (138) ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, March 31, 2020 ​ $ 819,133 ​

FAIR VALUE OF DERIVATIVES AND_2

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2020
FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS
Schedule of estimated fair values	The estimated fair values of the Company’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 Total assets ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 3,075 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 903,243 ​ ​ 908,088 ​ ​ — ​ ​ — ​ ​ 908,088 Credit facilities ​ 216,181 ​ 213,026 ​ — ​ — ​ 213,026 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ Revolving credit facility ​ ​ 50,000 ​ ​ 50,000 ​ ​ — ​ ​ — ​ ​ 50,000 Working capital credit facility ​ ​ 24,797 ​ ​ 24,797 ​ ​ — ​ ​ — ​ ​ 24,797 Commercial paper program ​ ​ 215,000 ​ ​ 215,000 ​ ​ — ​ ​ — ​ ​ 215,000 Unsecured notes ​ ​ 3,474,450 ​ ​ 3,466,082 ​ ​ — ​ ​ — ​ ​ 3,466,082 Total liabilities ​ $ 4,913,746 ​ $ 4,907,068 ​ $ — ​ $ 3,075 ​ $ 4,903,993 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 819,133 ​ $ 819,133 ​ $ — ​ $ 819,133 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 153,650 ​ $ 160,197 ​ $ — ​ $ — ​ $ 160,197 Derivatives - Interest rate contracts (c) ​ 6 ​ 6 ​ — ​ 6 ​ — Total assets ​ $ 153,656 ​ $ 160,203 ​ $ — ​ $ 6 ​ $ 160,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 142 ​ $ 142 ​ $ — ​ $ 142 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 906,228 ​ ​ 898,329 ​ ​ — ​ ​ — ​ ​ 898,329 Credit facilities ​ 218,490 ​ 213,661 ​ — ​ — ​ 213,661 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 16,583 ​ ​ 16,583 ​ ​ — ​ ​ — ​ ​ 16,583 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 3,263,152 ​ ​ 3,397,622 ​ ​ — ​ ​ — ​ ​ 3,397,622 Total liabilities ​ $ 4,731,595 ​ $ 4,853,337 ​ $ — ​ $ 142 ​ $ 4,853,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 1,018,665 ​ $ 1,018,665 ​ $ — ​ $ 1,018,665 ​ $ — (a) Balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) See Note 11, Derivatives and Hedging Activity . (d) See Note 7, Secured and Unsecured Debt, Net . (e) See Note 9, Noncontrolling Interests.

DERIVATIVES AND HEDGING ACTIV_2

DERIVATIVES AND HEDGING ACTIVITY (Tables)	3 Months Ended
	Mar. 31, 2020
DERIVATIVES AND HEDGING ACTIVITY
Schedule of outstanding interest rate derivatives	As of March 31, 2020, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ Product ​ Instruments ​ Notional Interest rate swaps ​ 1 ​ $ 315,000 ​ Derivatives not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of GAAP. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings and resulted in no gain or loss for both the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Company had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps ​ 1 ​ $ 19,880
Fair value of Company's derivative financial instruments and their classification on Consolidated Balance Sheets	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ March 31, ​ December 31, ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ — ​ $ 6 ​ $ 3,075 ​ $ 142
Effect of Company's derivative financial instruments on Consolidated Statements of Operations	The tables below present the effect of the Company’s derivative financial instruments on the Consolidated Statements of Operations for the three months ended March 31, 2020 and 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain/(Loss) Recognized in ​ ​ ​ ​ Gain/(Loss) Reclassified ​ Interest expense ​ ​ Unrealized holding gain/(loss) ​ from Accumulated OCI into ​ (Amount Excluded from ​ ​ Recognized in OCI ​ Interest expense ​ Effectiveness Testing) Derivatives in Cash Flow Hedging Relationships 2020 2019 2020 2019 2020 2019 Three Months Ended March 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ (2,917) ​ $ (2,210) ​ $ (357) ​ $ 945 ​ $ — ​ $ —
Effect of Company's derivatives not designated as hedging instruments on the Consolidated Statements of Operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Total amount of Interest expense ​ $ 39,317 ​ $ 33,542 ​
Offsetting of Derivative Assets	The Company has elected not to offset derivative positions on the consolidated financial statements. The tables below present the effect on its financial position had the Company made the election to offset its derivative positions as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount March 31, 2020 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 6 ​ $ — ​ $ 6 ​ $ (3) ​ $ — ​ $ 3 (a) Amounts reconcile to the aggregate fair value of derivative assets in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.
Offsetting of Derivative Liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Liabilities ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount March 31, 2020 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — ​ $ — ​ $ 3,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 142 ​ $ — ​ $ 142 ​ $ (3) ​ $ — ​ $ 139 (a) Amounts reconcile to the aggregate fair value of derivative liabilities in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	3 Months Ended
	Mar. 31, 2020
COMMITMENTS AND CONTINGENCIES
Summary of real estate commitments	The following summarizes the Company’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Wholly-owned — under development 3 ​ $ 95,326 ​ $ 183,174 Wholly-owned — redevelopment 2 ​ ​ 17,660 ​ ​ 7,840 Joint ventures: ​ ​ Preferred equity investments 2 ​ ​ 34,647 (b) ​ 14,348 (c) Other investments ​ - ​ ​ 14,364 ​ ​ 23,700 (d) Total ​ $ 161,997 ​ $ 229,062 (a) Represents UDR’s investment as of March 31, 2020. (b) Represents UDR’s investment in Modera Lake Merritt and Thousand Oaks, which were under development as of March 31, 2020. (c) Represents UDR’s remaining commitment for Modera Lake Merritt and Thousand Oaks. (d) Represents UDR’s remaining commitment for other investment ventures.

REPORTABLE SEGMENTS (Tables)

REPORTABLE SEGMENTS (Tables)	3 Months Ended
	Mar. 31, 2020
REPORTABLE SEGMENTS
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to Net income/(loss)	The following table details rental income and NOI for UDR’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (a) ​ 2020 2019 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 102,616 ​ $ 98,633 Mid-Atlantic Region ​ 56,085 ​ 54,300 Northeast Region ​ 30,942 ​ 30,193 Southeast Region ​ 30,677 ​ 29,531 Southwest Region ​ 16,626 ​ 16,077 Non-Mature Communities/Other ​ 74,676 ​ 30,169 Total segment and consolidated lease revenue ​ $ 311,622 ​ $ 258,903 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 2,774 ​ $ 3,076 Mid-Atlantic Region ​ 1,573 ​ 2,002 Northeast Region ​ 501 ​ 629 Southeast Region ​ 1,429 ​ 1,790 Southwest Region ​ 590 ​ 763 Non-Mature Communities/Other ​ 1,604 ​ 759 Total segment and consolidated other revenue ​ $ 8,471 ​ $ 9,019 ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 105,390 ​ $ 101,709 Mid-Atlantic Region ​ 57,658 ​ 56,302 Northeast Region ​ 31,443 ​ 30,822 Southeast Region ​ 32,106 ​ 31,321 Southwest Region ​ 17,216 ​ 16,840 Non-Mature Communities/Other ​ 76,280 ​ 30,928 Total segment and consolidated rental income ​ $ 320,093 ​ $ 267,922 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ Same-Store Communities (a) ​ ​ West Region ​ $ 79,823 ​ $ 76,984 Mid-Atlantic Region ​ 40,377 ​ 39,179 Northeast Region ​ 20,614 ​ 20,977 Southeast Region ​ 22,617 ​ 22,010 Southwest Region ​ 11,056 ​ 10,328 Non-Mature Communities/Other ​ 50,978 ​ 20,205 Total segment and consolidated NOI ​ 225,465 ​ 189,683 Reconciling items: ​ ​ Joint venture management and other fees ​ 1,388 ​ 2,751 Property management ​ (9,203) ​ (7,703) Other operating expenses ​ (4,966) ​ (5,646) Real estate depreciation and amortization ​ (155,476) ​ (112,468) General and administrative ​ (14,978) ​ (12,467) Casualty-related (charges)/recoveries, net ​ (1,251) ​ — Other depreciation and amortization ​ (2,025) ​ (1,656) Income/(loss) from unconsolidated entities ​ 3,367 ​ 49 Interest expense ​ (39,317) ​ (33,542) Interest income and other income/(expense), net ​ 2,700 ​ 9,813 Tax (provision)/benefit, net ​ (164) ​ (2,212) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) Net income/(loss) attributable to UDR, Inc. ​ $ 5,221 ​ $ 24,503 (a) Same-Store Community population consisted of 37,910 apartment homes. ​
Details of assets of UDR's reportable segments	The following table details the assets of UDR’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 3,704,480 ​ $ 3,696,544 Mid-Atlantic Region ​ 2,356,688 ​ 2,350,341 Northeast Region ​ 1,501,767 ​ 1,500,597 Southeast Region ​ 810,984 ​ 806,830 Southwest Region ​ 603,082 ​ 600,350 Non-Mature Communities/Other ​ 3,840,997 ​ 3,647,439 Total segment assets ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Total segment assets — net book value ​ 8,545,527 ​ 8,470,748 Reconciling items: ​ ​ Cash and cash equivalents ​ 980 ​ 8,106 Restricted cash ​ 21,949 ​ 25,185 Notes receivable, net ​ 151,543 ​ 153,650 Investment in and advances to unconsolidated joint ventures, net ​ 588,395 ​ 588,262 Operating lease right-of-use assets ​ ​ 203,410 ​ ​ 204,225 Other assets ​ 179,301 ​ 186,296 Total consolidated assets ​ $ 9,691,105 ​ $ 9,636,472 (a) Same-Store Community population consisted of 37,910 apartment homes. ​

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details)	Mar. 31, 2020itemcommunityshares	Dec. 31, 2019shares
Consolidation And Basis Of Presentation
Number of Real Estate Properties | community	150
Number Of Apartment Homes Owned And Consolidated By Company | item	47,579
Operating Partnership units outstanding related to limited partner	184,836,000	184,064,000
Operating Partnership outstanding units	184.8
United Dominion Realty L.P.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	176.2
General Partnership units outstanding	100,000
General Partners' ownership (as a percent)	95.30%
UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating Partnership outstanding units	13.5
Percentage of units outstanding in Partnership	41.60%
UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating Partnership outstanding units	32.4
Non-affiliated Partners
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	8.6
Operating Partnership outstanding units	13.8
Percentage of units outstanding in Partnership	4.70%
Non-affiliated Partners | United Dominion Realty L.P.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	8.6
Operating Partnership outstanding units		7.9
Percentage of units outstanding in Partnership	4.70%	4.30%
Non-affiliated Partners | UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Percentage of units outstanding in Partnership	42.60%
UDR, Inc.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	176,100,000	176,100,000
General Partners' ownership (as a percent)	57.40%
Operating Partnership outstanding units	18.6
Percentage of units outstanding in Partnership	95.30%	95.70%
UDR, Inc. | United Dominion Realty L.P.
Consolidation And Basis Of Presentation
General Partnership units outstanding	176.2
General Partners' ownership (as a percent)	95.30%
Operating Partnership outstanding units		176,200,000
Percentage of units outstanding in Partnership		95.70%
United Dominion Realty L.P.
Consolidation And Basis Of Presentation
Number of Real Estate Properties | community	52
Number of Markets Operating Within | item	15
Number Of Apartment Homes Owned And Consolidated By Company | item	16,434
Operating Partnership units outstanding related to limited partner	184,724,677	183,952,659
General Partnership units outstanding	110,883	110,883
Operating Partnership outstanding units	184,800,000	184,100,000

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Nov. 30, 2019USD ($)home	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Apr. 30, 2020	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Accounting policies
Recognition of operating lease right-of-use assets		$ 203,410				$ 204,225
Recognition of operating lease liabilities		197,829				198,558
Allocation of other comprehensive income/(loss)		(138)
Significant Accounting Policies
Development costs excluding direct costs and capitalized interest		6,900	$ 3,300
Interest capitalized during period		1,400	1,100
Notes receivable		152,300				153,650
Allowance for credit losses		(757)
Notes receivable, net		151,543				153,650
Interest Income, Related Party		0	0
Note receivable interest income		2,600	1,100
Current Income Tax Expense (Benefit)		0
Deferred tax liabilities, net		(1,400)
Unrecognized tax benefit, accrued interest or penalties due to examination		0
Bellevue, WA 259 Home Community
Significant Accounting Policies
Number of apartment homes | home	259
Note due April 2020
Significant Accounting Policies
Notes receivable		$ 20,000				20,000
Note receivable interest rate		12.00%		8.00%
Note due October 2020
Significant Accounting Policies
Notes receivable						2,250
Note receivable interest rate		8.00%
Note due October 2022
Significant Accounting Policies
Notes receivable		$ 115,000				115,000
Note receivable interest rate		4.75%
Note due October 2022 | Bellevue, WA 259 Home Community
Significant Accounting Policies
Aggregate commitment on note receivable	$ 115,000
Deposit made under purchase option agreement	10,000
Payment to acquire real estate	$ 170,000
Purchase option exercisable term	30 days
Maturity date extension term	10 years
Loan interest term	3 years
Amortization schedule term	30 years
Note due January 2023
Significant Accounting Policies
Notes receivable		$ 17,300				16,400
Notes receivable, net		$ 17,300
Note receivable interest rate		10.00%
Aggregate commitment on note receivable		$ 20,000
Additional amount loaned		900
Note maturity public capital threshold		5,000
Maximum
Significant Accounting Policies
Deferred tax liabilities, net						$ (1,600)
ASU 2016-13
Accounting policies
Retained earnings					$ 2,200
Noncontrolling Interests
Accounting policies
Allocation of other comprehensive income/(loss)		$ (100)	$ (300)

REAL ESTATE OWNED - Summarizes

REAL ESTATE OWNED - Summarizes the carrying amounts for our real estate owned (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned
Land	$ 2,163,055	$ 2,164,032
Depreciable property - held and used:
Land improvements	225,850	224,964
Building, improvements, and furniture, fixtures and equipment	10,178,547	10,102,758
Real estate intangible assets	40,570	40,570
Under development:
Real estate under development	95,245	69,754
Real estate owned	12,817,998	12,602,101
Accumulated depreciation	(4,272,471)	(4,131,353)
Total real estate owned, net of accumulated depreciation	8,545,527	8,470,748
Land and land improvements
Under development:
Real estate under development	29,226	29,226
Real estate held for disposition	16,245
Building, improvements and furniture, fixtures and equipment
Under development:
Real estate under development	66,100	$ 40,551
Real estate held for disposition	$ 98,405

REAL ESTATE OWNED - Additional

REAL ESTATE OWNED - Additional Information (Details) $ in Thousands	May 07, 2020USD ($)home	Jan. 31, 2020USD ($)home	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)communityitemstate	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Real Estate Owned Disclosure
Number of real estate properties | community				150
Number of states in which there are owned and consolidated communities | state				13
Number of apartment homes owned and consolidated | item				47,579
In-place intangibles				$ 40,570		$ 40,570
Development of real estate assets				23,087	$ 6,237
Real estate held for investment				12,608,022		$ 12,532,324
Long-term Debt				$ 4,869,119
294 Home Operating Community in Tampa
Real Estate Owned Disclosure
Real estate acquired		$ 85,200
Number of apartment homes acquired | home		294
Real estate acquired		$ 83,100
In-place intangibles		$ 2,100
Operating Community in Seattle | Forecast
Real Estate Owned Disclosure
Proceeds from sale of real estate			$ 49,700
196 Home Operating Community in Seattle
Real Estate Owned Disclosure
Apartment homes sold | home	196
Proceeds from sale of real estate	$ 92,900
Gain on sale of real estate owned	$ 31,700
Preferred Equity Investment Hillsboro Oregon
Real Estate Owned Disclosure
Number of apartment homes | home		276
Number of apartment homes acquired | home		276
Ownership (as a percent)		100.00%				49.00%
Payment to acquire real estate		$ 21,600
Repayments of joint venture construction financing		35,600
Real estate acquired		67,800
In-place intangibles		1,700
Gain on consolidation		$ 0

JOINT VENTURES AND PARTNERSHI_3

JOINT VENTURES AND PARTNERSHIPS - Summary (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)communitypropertyhome	Mar. 31, 2019USD ($)	Feb. 29, 2020USD ($)home	Jan. 31, 2020home	Dec. 31, 2019USD ($)
Unconsolidated entities
Investment in unconsolidated entities	$ 585,091				$ 585,490
Number of real estate properties | community	150
Financial information relating to unconsolidated joint ventures operations
Operating income/(loss)	$ 3,367	$ 49
Unconsolidated Joint Ventures
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	1,868,502				1,901,081
Cash and cash equivalents	32,486				29,823
Other assets	180,893				172,941
Total assets	2,081,881				2,103,845
Third party debt, net	1,136,306				1,148,048
Accounts payable and accrued liabilities	50,262				55,114
Total liabilities	1,186,568				1,203,162
Total equity	895,313				$ 900,683
Financial information relating to unconsolidated joint ventures operations
Total revenues	41,314	81,532
Property operating expenses	15,297	30,312
Real estate depreciation and amortization	16,243	29,580
Operating income/(loss)	9,774	21,640
Interest expense	(10,347)	(21,924)
Net unrealized gain/(loss) on held investments		1,522
Other income/(loss)	(8)	103
Net income /(loss)	(581)	1,341
Preferred Equity Investment Hillsboro Oregon
Unconsolidated entities
Number of apartment homes | home				276
UDR's Ownership Interest				100.00%	49.00%
Preferred Equity Investment Thousand Oaks
Unconsolidated entities
Number of apartment homes | home			142
UDR commitment			$ 20,100
Rate			9.00%
Operating Community
Unconsolidated entities
Investment in unconsolidated entities	308,274				$ 313,053
Income from investments	$ (2,433)	(3,887)
Operating Community | Unconsolidated Joint Venture UDR Met Life I Partnership
Unconsolidated entities
Number of apartment homes | home	150
Investment in unconsolidated entities	$ 28,570				$ 28,812
UDR's Ownership Interest	50.00%				50.00%
Number of real estate properties | property	1
Income from investments	$ (454)	(576)
Operating Community | Unconsolidated Joint Venture UDR MetLife II Partnership
Unconsolidated entities
Number of apartment homes | home	1,250
Investment in unconsolidated entities	$ 150,652				$ 150,893
UDR's Ownership Interest	50.00%				50.00%
Number of real estate properties | property	7
Income from investments	$ (91)	434
Operating Community | Unconsolidated Joint Venture Other MetLife
Unconsolidated entities
Number of apartment homes | home	1,437
Investment in unconsolidated entities	$ 94,109				$ 98,441
UDR's Ownership Interest	50.60%				50.60%
Number of real estate properties | property	5
Income from investments	$ (1,811)	(1,777)
Operating Community | Unconsolidated Joint Venture West Coast Development JV
Unconsolidated entities
Number of apartment homes | home	293
Investment in unconsolidated entities	$ 34,943				$ 34,907
UDR's Ownership Interest	47.00%				47.00%
Number of real estate properties | property	1
Income from investments	$ (77)	(149)
Operating Community | Sold Joint Ventures
Unconsolidated entities
Income from investments		(1,819)
Development Community
Unconsolidated entities
Investment in unconsolidated entities	276,817				$ 272,437
Income from investments	$ 5,800	3,936
Development Community | Preferred Equity Investment Hillsboro Oregon
Unconsolidated entities
Investment in unconsolidated entities					17,064
Rate	6.50%
Income from investments	$ (46)	(161)
Development Community | Preferred Equity Investment 1532 Harrison San Francisco, CA
Unconsolidated entities
Investment in unconsolidated entities	31,426				30,585
UDR commitment	$ 24,645
Rate	11.00%
Years to Maturity	2 years 3 months 18 days
Income from investments	$ 836	748
Participating Loan Years to Maturity	2 years 3 months 18 days
Development Community | Preferred Equity Investment 1200 Broadway Nashville TN
Unconsolidated entities
Investment in unconsolidated entities	$ 65,254				63,958
UDR commitment	$ 55,558
Rate	8.00%
Years to Maturity	2 years 6 months
Income from investments	$ 1,281	1,169
Participating Loan Years to Maturity	2 years 6 months
Development Community | Preferred Equity Investment 1641 Lincoln Santa Monica CA
Unconsolidated entities
Investment in unconsolidated entities	$ 10,693				10,379
UDR commitment	$ 8,800
Rate	12.00%
Years to Maturity	2 years 3 months 18 days
Income from investments	$ 314	275
Participating Loan Years to Maturity	2 years 3 months 18 days
Development Community | Preferred Equity Investment 1300 Fairmount Philadelphia, PA
Unconsolidated entities
Investment in unconsolidated entities	$ 55,840				51,215
UDR commitment	$ 51,393
Years to Maturity	3 years 4 months 24 days
Income from investments	$ 1,166	275
Participating Loan Years to Maturity	3 years 4 months 24 days
Development Community | Preferred Equity Investment Essex Orlando, FL
Unconsolidated entities
Investment in unconsolidated entities	$ 15,270				14,804
UDR commitment	$ 12,886
Rate	12.50%
Years to Maturity	3 years 4 months 24 days
Income from investments	$ 466	332
Participating Loan Years to Maturity	3 years 4 months 24 days
Development Community | Preferred Equity Investment Modera Lake Merritt, Oakland
Unconsolidated entities
Investment in unconsolidated entities	$ 28,653				22,653
UDR commitment	$ 27,250
Rate	9.00%
Years to Maturity	4 years
Income from investments	$ 574
Participating Loan Years to Maturity	4 years
Development Community | Preferred Equity Investment Thousand Oaks, CA
Unconsolidated entities
Investment in unconsolidated entities	$ 5,994
UDR commitment	$ 20,059
Rate	9.00%
Years to Maturity	4 years 10 months 24 days
Income from investments	$ 24
Participating Loan Years to Maturity	4 years 10 months 24 days
Development Community | Other Investment The Portals Washington, DC
Unconsolidated entities
Investment in unconsolidated entities	$ 49,323				48,181
UDR commitment	$ 38,559
Rate	11.00%
Years to Maturity	1 year 2 months 12 days
Income from investments	$ 1,335	1,173
Participating Loan Years to Maturity	1 year 2 months 12 days
Development Community | Other Investment Ventures
Unconsolidated entities
Investment in unconsolidated entities	$ 14,364				$ 13,598
UDR commitment	34,500
Income from investments	$ (150)	$ 125

JOINT VENTURES AND PARTNERSHI_4

JOINT VENTURES AND PARTNERSHIPS - Commitments (Details) $ in Thousands	1 Months Ended			3 Months Ended
	Apr. 30, 2020USD ($)	Jan. 31, 2020USD ($)home	Jan. 31, 2019USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Joint Ventures
Real estate owned				$ 12,817,998		$ 12,602,101
Second installment of payable incurred in partial consideration for acquisition of ownership interest in joint venture				33,560
Investment in unconsolidated entities				$ 585,091		585,490
Condition for Community considered to have stabilized occupancy				90%
Time to maintain percent occupancy to be considered a community				3 months
repayment of construction loan	$ 215,000
Investment in unconsolidated joint ventures				$ 16,139	$ 21,389
Long-term Debt				4,885,138		4,707,524
Deferred fees from the sale of properties				9,000		$ 9,000
Joint venture management and other fees					2,800
Joint venture management and other fees				$ 1,388	$ 2,751
Type of revenue				udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
Preferred Equity Investment Hillsboro Oregon
Joint Ventures
UDR's Ownership Interest		100.00%				49.00%
repayment of construction loan			$ 35,600
Number of apartment homes acquired | home		276
Payment to acquire real estate		$ 21,600
Gain on consolidation		$ 0
Number of apartment homes | home		276
13th and Market Properties LLC
Joint Ventures
Investment in unconsolidated entities				$ 3,300

LEASES - Lessee Future Minimum

LEASES - Lessee Future Minimum Payments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)community	Dec. 31, 2019USD ($)
Lessee operating leases
Number of communities subject to ground leases | community	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 203,410	$ 204,225
Weighted average remaining lease term	44 years 6 months
Weighted average discount rate	5.00%
Future minimum lease payments
Operating lease liabilities	$ 197,829	$ 198,558
Ground Leases
Future minimum lease payments
2020	9,330
2021	12,442
2022	12,442
2023	12,442
2024	12,442
Thereafter	455,221
Total future minimum lease payments (undiscounted)	514,319
Difference between future undiscounted cash flows and discounted cash flows	(316,490)
Operating lease liabilities	$ 197,829

LEASES - Lessee Expenses (Detai

LEASES - Lessee Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee operating leases
Contractual ground lease expense	$ 100	$ 100
Variable lease expense	100	200
Operating lease right-of-use asset amortization	800	200
Operating lease liabilities amortization	700	100
Ground Leases
Lessee operating leases
Contractual ground lease expense	3,170	2,159
Variable lease expense	43	139
Ground Leases | Other operating expense
Lessee operating leases
Total lease expense	$ 3,213	$ 2,298

LEASES - Lessor (Details)

LEASES - Lessor (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Future minimum lease payments
Variable lease expense	$ 100	$ 200
Ground Leases
Future minimum lease payments
Variable lease expense	$ 43	$ 139
Apartment Homes
Lessor leases
Percentage of lease revenue	98.40%
Option to extend	true
Apartment Homes | Maximum
Lessor leases
Lease terms	12 months
Retail and Commercial Spaces
Lessor leases
Percentage of lease revenue	1.60%
Option to extend	true
Future minimum lease payments
2020	$ 16,849
2021	22,487
2022	20,781
2023	19,317
2024	17,594
Thereafter	81,662
Total future minimum payments	$ 178,690
Retail and Commercial Spaces | Minimum
Lessor leases
Lease terms	5 years
Retail and Commercial Spaces | Maximum
Lessor leases
Lease terms	15 years

SECURED AND UNSECURED DEBT, N_3

SECURED AND UNSECURED DEBT, NET - Summary (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)community	Feb. 29, 2020USD ($)	Dec. 31, 2019USD ($)
Secured debt instruments
Unamortized net premium	$ 32,700		$ 35,300
Interest rate at end of the period	3.28%
Long-term Debt	$ 4,885,138		4,707,524
Unsecured Debt	3,740,937		3,558,083
Borrowings outstanding	$ 2,500		2,900
Weighted Average
Secured debt instruments
Years to maturity	7 years 1 month 6 days
Commercial Paper
Secured debt instruments
Borrowings outstanding at end of period	$ 215,000		300,000
Mortgages Note Payable | Fixed Rate Debt
Secured debt instruments
Principal outstanding	$ 883,249		884,869
Interest rate at end of the period	3.61%
Number of Communities Encumbered | community	15
Mortgages Note Payable | Fixed Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	5 years 10 months 24 days
Tax-exempt secured notes payable | Variable Rate Debt
Secured debt instruments
Principal outstanding	$ 27,000		27,000
Interest rate at end of the period	1.91%
Number of Communities Encumbered | community	1
Tax-exempt secured notes payable | Variable Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	12 years
Credit facilities | Fixed Rate Debt
Secured debt instruments
Principal outstanding	$ 203,429		204,590
Interest rate at end of the period	4.90%
Number of Communities Encumbered | community	4
Credit facilities | Fixed Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	2 years 9 months 18 days
Secured Debt
Secured debt instruments
Principal outstanding	$ 1,144,201		1,149,441
Interest rate at end of the period	3.80%
Long-term Debt	$ 1,144,201
Number of Communities Encumbered | community	20
Secured Debt | Weighted Average
Secured debt instruments
Years to maturity	5 years 6 months
Secured Debt | Fixed Rate Debt
Secured debt instruments
Principal outstanding	$ 1,117,263		1,122,505
Interest rate at end of the period	3.85%
Long-term Debt	$ 1,117,263
Number of Communities Encumbered | community	19
Deferred financing costs and other non-cash adjustments	$ (30,585)		(33,046)
Secured Debt | Fixed Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	5 years 3 months 18 days
Secured Debt | Variable Rate Debt
Secured debt instruments
Principal outstanding	$ 26,938		26,936
Interest rate at end of the period	1.91%
Long-term Debt	$ 26,938
Number of Communities Encumbered | community	1
Deferred finance costs, net	$ (62)		(64)
Secured Debt | Variable Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	12 years
Unsecured Revolving credit facility due 2023
Secured debt instruments
Interest rate at end of the period	1.75%
Borrowings outstanding	$ 50,000
Unsecured Revolving credit facility due 2023 | Weighted Average
Secured debt instruments
Years to maturity	2 years 9 months 18 days
Unsecured Revolving credit facility due 2020 | Commercial Paper
Secured debt instruments
Interest rate at end of the period	1.58%
Borrowings outstanding at end of period	$ 215,000		300,000
Unsecured Revolving credit facility due 2020 | Commercial Paper | Weighted Average
Secured debt instruments
Years to maturity	1 month 6 days
Unsecured Working Capital Credit Facility
Secured debt instruments
Interest rate at end of the period	1.82%
Borrowings outstanding	$ 24,797		16,583
Unsecured Working Capital Credit Facility | Weighted Average
Secured debt instruments
Years to maturity	9 months 18 days
Term Loan due September 2023
Secured debt instruments
Interest rate at end of the period	2.48%
Senior Notes	$ 35,000		35,000
Term Loan due September 2023 | Weighted Average
Secured debt instruments
Years to maturity	3 years 6 months
1.93% Term Loan due September 2023
Secured debt instruments
Interest rate at end of the period	1.93%
Senior Notes	$ 315,000		315,000
1.93% Term Loan due September 2023 | Weighted Average
Secured debt instruments
Years to maturity	3 years 6 months
3.75% Medium-Term Notes Due July 2024
Secured debt instruments
Unamortized discount	$ 443		470
Interest rate at end of the period	3.75%
Senior Notes	$ 299,557		299,530
3.75% Medium-Term Notes Due July 2024 | Weighted Average
Secured debt instruments
Years to maturity	4 years 3 months 18 days
8.50% Debentures, Due September 2024
Secured debt instruments
Interest rate at end of the period	8.50%
Senior Notes	$ 15,644		15,644
8.50% Debentures, Due September 2024 | Weighted Average
Secured debt instruments
Years to maturity	4 years 6 months
4.00% Medium-Term Note due October 2025
Secured debt instruments
Unamortized discount	$ 379		396
Interest rate at end of the period	4.00%
Senior Notes	$ 299,621		299,604
4.00% Medium-Term Note due October 2025 | Weighted Average
Secured debt instruments
Years to maturity	5 years 6 months
2.95% Medium-Term Note due September 2026
Secured debt instruments
Interest rate at end of the period	2.95%
Senior Notes	$ 300,000		300,000
2.95% Medium-Term Note due September 2026 | Weighted Average
Secured debt instruments
Years to maturity	6 years 4 months 24 days
3.50 Medium-Term Note due July 2027
Secured debt instruments
Unamortized discount	$ 511		529
Interest rate at end of the period	3.50%
Senior Notes	$ 299,489		299,471
3.50 Medium-Term Note due July 2027 | Weighted Average
Secured debt instruments
Years to maturity	7 years 3 months 18 days
3.50% Medium-Term Notes Due January 2028
Secured debt instruments
Unamortized discount	$ 924		954
Interest rate at end of the period	3.50%
Senior Notes	$ 299,076		299,046
3.50% Medium-Term Notes Due January 2028 | Weighted Average
Secured debt instruments
Years to maturity	7 years 9 months 18 days
4.40% Medium-Term Notes due January 2029
Secured debt instruments
Unamortized discount	$ 5		5
Interest rate at end of the period	4.40%
Senior Notes	$ 299,995		299,995
4.40% Medium-Term Notes due January 2029 | Weighted Average
Secured debt instruments
Years to maturity	8 years 9 months 18 days
3.20% Medium-Term Notes due January 2030
Secured debt instruments
Unamortized discount	$ 13,442		2,281
Interest rate at end of the period	3.20%
Senior Notes	$ 613,442	$ 600,000	402,281
3.20% Medium-Term Notes due January 2030 | Weighted Average
Secured debt instruments
Years to maturity	9 years 9 months 18 days
3.00% Medium-Term Notes due August 2031
Secured debt instruments
Unamortized discount	$ 1,099		1,123
Interest rate at end of the period	3.00%
Senior Notes	$ 398,901		398,877
3.00% Medium-Term Notes due August 2031 | Weighted Average
Secured debt instruments
Years to maturity	11 years 4 months 24 days
3.10% Medium-Term Notes due November 2034
Secured debt instruments
Principal outstanding	$ 298,713
Unamortized discount	$ 1,287		1,309
Interest rate at end of the period	3.10%
Senior Notes			298,691
3.10% Medium-Term Notes due November 2034 | Weighted Average
Secured debt instruments
Years to maturity	14 years 7 months 6 days
Other
Secured debt instruments
Senior Notes	$ 12		13
Unsecured Debt
Secured debt instruments
Interest rate at end of the period	3.29%
Long-term Debt	$ 3,740,937
Unsecured Debt	3,740,937		3,558,083
Deferred finance costs, net	$ (23,310)		(21,652)
Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	7 years 6 months
Credit facilities
Secured debt instruments
Principal outstanding	$ 203,400
Credit facilities | Fixed Rate Debt
Secured debt instruments
Interest rate at end of the period	4.90%
United Dominion Realty L.P.
Secured debt instruments
Interest rate at end of the period	2.83%
Long-term Debt	$ 99,082		99,071
Number of Communities Encumbered | community	2
United Dominion Realty L.P. | Weighted Average
Secured debt instruments
Years to maturity	10 years 4 months 24 days
United Dominion Realty L.P. | Fixed Rate Debt
Secured debt instruments
Interest rate at end of the period	3.10%
Long-term Debt	$ 72,144		72,135
Number of Communities Encumbered | community	1
United Dominion Realty L.P. | Fixed Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	9 years 9 months 18 days
United Dominion Realty L.P. | Variable Rate Debt
Secured debt instruments
Interest rate at end of the period	1.91%
Long-term Debt	$ 26,938		26,936
Number of Communities Encumbered | community	1
Deferred finance costs, net	$ (62)		(64)
United Dominion Realty L.P. | Variable Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	12 years
United Dominion Realty L.P. | Mortgages Note Payable
Secured debt instruments
Principal outstanding	$ 72,500
United Dominion Realty L.P. | Mortgages Note Payable | Fixed Rate Debt
Secured debt instruments
Principal outstanding	$ 72,500		72,500
Interest rate at end of the period	3.10%
Number of Communities Encumbered | community	1
Deferred finance costs, net	$ (356)		(365)
United Dominion Realty L.P. | Mortgages Note Payable | Fixed Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	9 years 9 months 18 days
United Dominion Realty L.P. | Tax-exempt secured notes payable | Variable Rate Debt
Secured debt instruments
Principal outstanding	$ 27,000		$ 27,000
Interest rate at end of the period	1.91%
Number of Communities Encumbered | community	1
United Dominion Realty L.P. | Tax-exempt secured notes payable | Variable Rate Debt | Weighted Average
Secured debt instruments
Years to maturity	12 years

SECURED AND UNSECURED DEBT, N_4

SECURED AND UNSECURED DEBT, NET - Variable Rate Debt (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Credit facilities
Unamortized net premium	$ 32.7	$ 35.3
Secured credit facilities
Borrowings outstanding at end of period	$ 2.5	$ 2.9

SECURED AND UNSECURED DEBT, N_5

SECURED AND UNSECURED DEBT, NET - Credit Facilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding at end of period	$ 2,500	$ 2,900
Unsecured Commercial Bank Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	2,000,000
Unsecured Revolving credit facility due 2023
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding at end of period	50,000
Unsecured Revolving credit facility due 2023 | Unsecured Commercial Bank Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	1,100,000
Term Loan due September 2023 | Unsecured Commercial Bank Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	350,000
Revolving Credit Facility | Unsecured Commercial Bank Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	1,100,000	1,100,000
Borrowings outstanding at end of period	50,000
Weighted average daily borrowings during the period ended	11,538	55
Maximum daily borrowings during the period ended	$ 50,000	$ 20,000
Weighted average interest rate during the period ended	1.80%	2.60%
Interest rate at the end of the period	1.80%
Unsecured Working Capital Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	$ 75,000	$ 75,000
Borrowings outstanding at end of period	24,797	16,583
Weighted average daily borrowings during the period ended	25,212	23,487
Maximum daily borrowings during the period ended	$ 46,419	$ 66,170
Weighted average interest rate during the period ended	2.20%	3.10%
Interest rate at the end of the period	1.80%	2.60%
Unsecured Commercial Paper | United Dominion Realty L.P.
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding at end of period	$ 215,000	$ 300,000

SECURED AND UNSECURED DEBT, N_6

SECURED AND UNSECURED DEBT, NET - Short Term Debt (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Commercial Paper
Unsecured Debt
Total unsecured commercial paper program	$ 500,000	$ 500,000
Borrowings outstanding at end of period	215,000	300,000
Weighted average daily borrowings during the period ended	346,978	173,353
Maximum daily borrowings during the period ended	$ 500,000	$ 435,000
Weighted average interest rate during the period ended	1.80%	2.50%
Interest rate at the end of the period	1.60%	2.00%
4.00% Medium-Term Note due October 2025
Unsecured Debt
Weighted average interest rate during the period ended	4.53%

SECURED AND UNSECURED DEBT, N_7

SECURED AND UNSECURED DEBT, NET - Unsecured Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Aggregate maturities of unsecured debt
2020	$ 327,592
2021	33,560
2022	9,159
2023	695,965
2024	410,924
2025	473,189
2026	351,070
2027	301,111
2028	422,465
2029	444,584
Thereafter	1,399,500
Subtotal	4,869,119
Non-cash (a)	16,019
Long-term Debt, Total	4,885,138	$ 4,707,524
Secured Debt
Aggregate maturities of unsecured debt
2020	112,592
2021	8,763
2022	9,159
2023	295,965
2024	95,280
2025	173,189
2026	51,070
2027	1,111
2028	122,465
2029	144,584
Thereafter	99,500
Subtotal	1,113,678
Non-cash (a)	30,523
Long-term Debt, Total	1,144,201
Unsecured Debt
Aggregate maturities of unsecured debt
2020	215,000
2021	24,797
2023	400,000
2024	315,644
2025	300,000
2026	300,000
2027	300,000
2028	300,000
2029	300,000
Thereafter	1,300,000
Subtotal	3,755,441
Non-cash (a)	(14,504)
Long-term Debt, Total	3,740,937
Fixed Rate Debt | Secured Debt
Aggregate maturities of unsecured debt
2020	112,592
2021	8,763
2022	9,159
2023	295,965
2024	95,280
2025	173,189
2026	51,070
2027	1,111
2028	122,465
2029	144,584
Thereafter	72,500
Subtotal	1,086,678
Non-cash (a)	30,585
Long-term Debt, Total	1,117,263
Variable Rate Debt | Secured Debt
Aggregate maturities of unsecured debt
Thereafter	27,000
Subtotal	27,000
Non-cash (a)	(62)
Long-term Debt, Total	$ 26,938

SECURED AND UNSECURED DEBT, N_8

SECURED AND UNSECURED DEBT, NET - Debt Covenants (Details) $ in Thousands	1 Months Ended			3 Months Ended
	Apr. 30, 2020USD ($)	Feb. 29, 2020USD ($)	Jul. 31, 2019USD ($)	Mar. 31, 2020USD ($)loan	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Oct. 31, 2019USD ($)
Fixed and variable rate debt
Amortization of financing costs				$ 1,000	$ 1,000
Secured Debt
Secured debt amount which encumbers real estate owned based upon book value				$ 2,100,000
Percentage of secured debt which encumbers real estate owned based upon book value				16.60%
Secured debt amount of real estate owned which is unencumbered				$ 10,700,000
Percentage of secured debt of real estate owned which is unencumbered				83.40%
Interest rate at end of the period				3.28%
Borrowings outstanding at end of period				$ 2,500		$ 2,900
Repayment of debt	$ 215,000
Unamortized net premium				$ 32,700		35,300
Weighted Average Interest Rate				3.28%
Unsecured Debt
Secured Debt
Interest rate at end of the period				3.29%
Credit facility interest rate				90
Basis points added to to variable rate				90.00%
Weighted Average Interest Rate				3.29%
Unsecured Debt | Maximum
Secured Debt
Basis points added to to variable rate				165.00%
Unsecured Debt | Minimum
Secured Debt
Basis points added to to variable rate				80.00%
Unsecured Working Capital Credit Facility
Secured Debt
Credit facilities with aggregate commitment				$ 75,000		75,000
Interest rate at end of the period				1.82%
Credit facility interest rate				82.5
Borrowings outstanding at end of period				$ 24,797		16,583
Weighted Average Interest Rate				1.82%
Unsecured Working Capital Credit Facility | Maximum
Secured Debt
Basis points added to to variable rate				145.00%
Unsecured Working Capital Credit Facility | Minimum
Secured Debt
Basis points added to to variable rate				75.00%
Unsecured Revolving credit facility due 2023
Secured Debt
Interest rate at end of the period				1.75%
Borrowings outstanding at end of period				$ 50,000
Weighted Average Interest Rate				1.75%
3.75% Medium-Term Notes Due July 2024
Secured Debt
Interest rate at end of the period				3.75%
Portion of medium term note subject to interest rate swaps				$ 100,000
Long-term Debt, Weighted Average Interest Rate				3.69%
Senior Notes				$ 299,557		299,530
Weighted Average Interest Rate				3.75%
Mortgages Note Payable | Fixed Rate Debt
Secured Debt
Principal outstanding				$ 883,249		884,869
Interest rate at end of the period				3.61%
Weighted Average Interest Rate				3.61%
Debt Assumed As Part of Acquisition
Secured Debt
Amortization of debt discount (Premium)				$ 2,600	$ 600
Tax-exempt secured notes payable | Variable Rate Debt
Secured Debt
Principal outstanding				$ 27,000		27,000
Interest rate at end of the period				1.91%
Weighted Average Interest Rate				1.91%
Credit facilities | Fixed Rate Debt
Secured Debt
Principal outstanding				$ 203,429		204,590
Interest rate at end of the period				4.90%
Weighted Average Interest Rate				4.90%
Tax-exempt secured notes payable | Variable Rate Debt
Secured Debt
Notes payable maximum interest rates range				1.91%
Revolving Credit Facility
Secured Debt
Basis points added to to variable rate				82.50%
Commitment fee				15.00%
Revolving Credit Facility | Maximum
Secured Debt
Basis points added to to variable rate				145.00%
Commitment fee				30.00%
Revolving Credit Facility | Minimum
Secured Debt
Basis points added to to variable rate				75.00%
Commitment fee				10.00%
4.00% Medium-Term Note due October 2025
Secured Debt
Interest rate at end of the period				4.00%
Portion of medium term note subject to interest rate swaps				$ 200,000
Senior Notes				$ 299,621		299,604
Weighted Average Interest Rate				4.00%
4.40% Medium-Term Notes due January 2029
Secured Debt
Interest rate at end of the period				4.40%
Portion of medium term note subject to interest rate swaps				$ 150,000
Long-term Debt, Weighted Average Interest Rate				4.27%
Senior Notes				$ 299,995		299,995
Weighted Average Interest Rate				4.40%
2.95% Medium-Term Note due September 2026
Secured Debt
Interest rate at end of the period				2.95%
Senior Notes				$ 300,000		300,000
Weighted Average Interest Rate				2.95%
3.20% Medium-Term Notes due January 2030
Secured Debt
Interest rate at end of the period				3.20%
Interest rate		3.20%	3.20%				3.20%
Long-term Debt, Weighted Average Interest Rate			3.42%
Senior Notes		$ 600,000		$ 613,442		402,281
Debt		$ 200,000	$ 300,000				$ 100,000
Price as percentage of principal amount		105.660
Weighted Average Interest Rate				3.20%
3.00% Medium-Term Notes due August 2031
Secured Debt
Interest rate at end of the period				3.00%
Senior Notes				$ 398,901		398,877
Weighted Average Interest Rate				3.00%
3.24% Notes due on 2030
Secured Debt
Interest rate				3.24%
Debt			$ 300,000				$ 100,000
Medium-Term Notes Due August 2031
Secured Debt
Debt				$ 150,000
Medium-Term Notes Due August 2031 | Weighted Average
Secured Debt
Interest rate at end of the period				3.01%
Weighted Average Interest Rate				3.01%
3.10% senior unsecured notes due 2034 | Weighted Average
Secured Debt
Interest rate at end of the period				3.13%
Weighted Average Interest Rate				3.13%
Unsecured Commercial Bank Credit Facility
Secured Debt
Credit facilities with aggregate commitment				$ 2,000,000
Repayment of debt				215,000
Unsecured Commercial Bank Credit Facility | Unsecured Revolving credit facility due 2023
Secured Debt
Credit facilities with aggregate commitment				$ 1,100,000
Number of Extensions of loan | loan				2
Extension period of option on loan				6 months
Unsecured Commercial Bank Credit Facility | Revolving Credit Facility
Secured Debt
Credit facilities with aggregate commitment				$ 1,100,000		1,100,000
Borrowings outstanding at end of period				$ 50,000
United Dominion Realty L.P.
Secured Debt
Notes payable maximum interest rates range				3.28%
Interest rate at end of the period				2.83%
Weighted Average Interest Rate				2.83%
United Dominion Realty L.P. | Fixed Rate Debt
Secured Debt
Interest rate at end of the period				3.10%
Weighted Average Interest Rate				3.10%
United Dominion Realty L.P. | Variable Rate Debt
Secured Debt
Interest rate at end of the period				1.91%
Weighted Average Interest Rate				1.91%
United Dominion Realty L.P. | Mortgages Note Payable
Secured Debt
Principal outstanding				$ 72,500
Interest rate				3.10%
United Dominion Realty L.P. | Mortgages Note Payable | Fixed Rate Debt
Secured Debt
Principal outstanding				$ 72,500		72,500
Interest rate at end of the period				3.10%
Weighted Average Interest Rate				3.10%
United Dominion Realty L.P. | Tax-exempt secured notes payable | Variable Rate Debt
Secured Debt
Principal outstanding				$ 27,000		27,000
Interest rate at end of the period				1.91%
Weighted Average Interest Rate				1.91%
United Dominion Realty L.P. | Unsecured Commercial Paper
Secured Debt
Borrowings outstanding at end of period				$ 215,000		300,000
Credit facilities
Secured Debt
Principal outstanding				$ 203,400
Credit facilities | Fixed Rate Debt
Secured Debt
Interest rate at end of the period				4.90%
Weighted Average Interest Rate				4.90%
Credit facilities | Fair Value, Measurements, Recurring | Carrying Amount | Credit facilities | Fixed Rate Debt
Secured Debt
Principal outstanding						218,490
Mortgages Note Payable | Fixed Rate Debt | Maximum
Secured Debt
Notes payable maximum interest rates range				4.35%
Mortgages Note Payable | Fixed Rate Debt | Minimum
Secured Debt
Notes payable maximum interest rates range				2.70%
Mortgages Note Payable | Fair Value, Measurements, Recurring | Carrying Amount | Mortgages Note Payable | Fixed Rate Debt
Secured Debt
Principal outstanding				$ 903,243		$ 906,228

INCOME_(LOSS) PER SHARE (Detail

INCOME/(LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Jul. 31, 2017
Antidilutive securities
Net income/(loss)	$ 5,540	$ 26,602
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(313)	(2,057)
Net (income)/loss attributable to noncontrolling interests	(6)	(42)
Net income/(loss) attributable to UDR, Inc.	5,221	24,503
Distributions to preferred stockholders - Series E (Convertible)	(1,066)	(1,011)
Net income/(loss) attributable to common stockholders	$ 4,155	$ 23,492
Denominator for earnings per share - basic and diluted:
Weighted average common shares outstanding	294,731,000	277,297,000
Non-vested restricted stock awards	(274,000)	(295,000)
Denominator for basic income/(loss) per share	294,457,000	277,002,000
Incremental shares issuable from assumed conversion of unvested LTIP Units and unvested restricted stock	703,000	555,000
Denominator for diluted income/(loss) per share	295,160,000	277,557,000
Income/(loss) per weighted average common share - basic	$ 0.01	$ 0.08
Income/(loss) per weighted average common share - diluted	$ 0.01	$ 0.08
Number of shares authorized	350,000,000		350,000,000
Aggregate gross proceeds		$ 192,179
Proceeds from the issuance of common shares through public offering, net		192,179
Aggregate net proceeds from sales, after deducting related costs		$ 192,179
OP/DownREIT Units
Antidilutive securities
Antidilutive securities	22,228,000	24,280,000
Convertible preferred stock
Antidilutive securities
Antidilutive securities	3,011,000	3,011,000
Unvested LTIP Units and unvested restricted stock
Antidilutive securities
Antidilutive securities	703,000	555,000
ATM
Denominator for earnings per share - basic and diluted:
Number of shares authorized				20,000,000
Shares of common stock available for future issuance	11,700,000
Forward Sales Agreement
Denominator for earnings per share - basic and diluted:
Number of shares authorized	2,100,000
Weighted average price per share	$ 49.56
Forward purchase agreement	0
Shares settled	0

NONCONTROLLING INTERESTS (Detai

NONCONTROLLING INTERESTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Redeemable noncontrolling interests in the Operating Partnership
Minimum holding period prior to redemption (in years)	1 year
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, beginning of year	$ 1,018,665
Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(205,713)	$ 144,197
Conversion of OP Units/DownREIT Units to Common Stock	(7,830)
Net income/(loss) attributable o redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	313	2,057
Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(9,182)
Vesting of Long-Term Incentive Plan Units	23,018
Allocation of other comprehensive income/(loss)	(138)
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, end of year	819,133
Net income/(loss) attributable to noncontrolling interests	(10)	30
Maximum
Redeemable noncontrolling interests in the Operating Partnership
Net income/(loss) attributable to noncontrolling interests	$ (100)	$ (100)
LTIP Units | Minimum
Redeemable noncontrolling interests in the Operating Partnership
Vesting period	1 year
LTIP Units | Maximum
Redeemable noncontrolling interests in the Operating Partnership
Vesting period	3 years

FAIR VALUE OF DERIVATIVES AND_3

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value
Notes receivable, net	$ 151,543	$ 153,650
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Gross Amounts of Recognized Assets		6
Gross Amounts of Recognized Liabilities	3,075	142
Unsecured debt instruments
Redeemable Noncontrolling Interest, Equity, Carrying Amount	819,133	1,018,665
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	819,133	1,018,665
Transfer Between the Levels	0
Credit facilities
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	203,400
Carrying Amount | Fair Value, Measurements, Recurring
Fair Value
Notes receivable, net	151,543	153,650
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	151,543	153,656
Unsecured debt instruments
Total liabilities	4,913,746	4,731,595
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	819,133	1,018,665
Carrying Amount | Interest rate contracts | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value		6
Derivatives - Interest rate contracts (b)	3,075	142
Carrying Amount | Revolving Credit Facility | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	50,000
Carrying Amount | Credit facilities | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	24,797
Carrying Amount | Commercial bank | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments		16,583
Commercial paper program	215,000	300,000
Carrying Amount | Senior Unsecured Notes | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	3,474,450	3,263,152
Fair Value | Fair Value, Measurements, Recurring
Fair Value
Notes receivable, net	160,515	160,197
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	160,515	160,203
Unsecured debt instruments
Total liabilities	4,907,068	4,853,337
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	819,133	1,018,665
Fair Value | Interest rate contracts | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value		6
Derivatives - Interest rate contracts (b)	3,075	142
Fair Value | Revolving Credit Facility | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	50,000
Fair Value | Credit facilities | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	24,797
Fair Value | Commercial bank | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments		16,583
Commercial paper program	215,000	300,000
Fair Value | Senior Unsecured Notes | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	3,466,082	3,397,622
Fair Value | Level 2 | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets		6
Unsecured debt instruments
Total liabilities	3,075	142
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	819,133	1,018,665
Fair Value | Level 2 | Interest rate contracts | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Derivative Asset Designated as Hedging Instrument, Fair Value		6
Derivatives - Interest rate contracts (b)	3,075	142
Fair Value | Level 3 | Fair Value, Measurements, Recurring
Fair Value
Notes receivable, net	160,515	160,197
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	160,515	160,197
Unsecured debt instruments
Total liabilities	4,903,993	4,853,195
Fair Value | Level 3 | Revolving Credit Facility | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	50,000
Fair Value | Level 3 | Credit facilities | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	24,797
Fair Value | Level 3 | Commercial bank | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments		16,583
Commercial paper program	215,000	300,000
Fair Value | Level 3 | Senior Unsecured Notes | Fair Value, Measurements, Recurring
Unsecured debt instruments
Unsecured debt instruments	3,466,082	3,397,622
Tax-exempt secured notes payable | Variable Rate Debt
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	27,000	27,000
Tax-exempt secured notes payable | Variable Rate Debt | Carrying Amount | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	27,000	27,000
Tax-exempt secured notes payable | Variable Rate Debt | Fair Value | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Tax-exempt secured notes payable | Variable Rate Debt | Fair Value | Level 3 | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Credit facilities | Fixed Rate Debt
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	203,429	204,590
Credit facilities | Fixed Rate Debt | Carrying Amount | Credit facilities | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale		218,490
Debt instruments - fair value
Fair value	216,181
Credit facilities | Fixed Rate Debt | Fair Value | Credit facilities | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	213,026	213,661
Credit facilities | Fixed Rate Debt | Fair Value | Level 3 | Credit facilities | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	213,026	213,661
Mortgages Note Payable | Fixed Rate Debt
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	883,249	884,869
Mortgages Note Payable | Fixed Rate Debt | Carrying Amount | Mortgages Note Payable | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Secured debt including debt on real estate held for sale	903,243	906,228
Mortgages Note Payable | Fixed Rate Debt | Fair Value | Mortgages Note Payable | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	908,088	898,329
Mortgages Note Payable | Fixed Rate Debt | Fair Value | Level 3 | Mortgages Note Payable | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	$ 908,088	$ 898,329

DERIVATIVES AND HEDGING ACTIV_3

DERIVATIVES AND HEDGING ACTIVITY - Interest Rate Derivatives (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)instrument	Mar. 31, 2019USD ($)
Derivatives
Unrealized holding gain/(loss)	$ (2,917)	$ (2,210)
Unsecured Commercial Bank Credit Facility
Derivatives
Total revolving credit facility	$ 2,000,000
Designated as Hedging Instrument | Interest rate swaps
Derivatives
Number of Interest Rate Derivatives Held | instrument	1
Notional	$ 315,000
Not Designated as Hedging Instrument | Interest rate caps
Derivatives
Number of Interest Rate Derivatives Held | instrument	1
Notional	$ 19,880

DERIVATIVES AND HEDGING ACTIV_4

DERIVATIVES AND HEDGING ACTIVITY - Undesignated Interest Rate Derivatives (Details) - Interest rate contracts - Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Other assets
Fair value of Company's derivative financial instruments and their classification on Consolidated Balance Sheet
Derivative Asset Designated as Hedging Instrument, Fair Value		$ 6
Other liabilities
Fair value of Company's derivative financial instruments and their classification on Consolidated Balance Sheet
Derivative Liability Designated as Hedging Instrument, Fair Value	$ 3,075	$ 142

DERIVATIVES AND HEDGING ACTIV_5

DERIVATIVES AND HEDGING ACTIVITY - Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Effect of derivative instruments on the Consolidated Statements of Operations
Unrealized holding gain/(loss)	$ (2,917)	$ (2,210)
Interest rate contracts | Interest expense | Cash Flow Hedging
Effect of derivative instruments on the Consolidated Statements of Operations
Unrealized holding gain/(loss)	(2,917)	(2,210)
Gain/(Loss) reclassified from Accumulated OCI in Interest Expense	(357)	945
Interest rate contracts | Other income/(expense)
Effect of derivative instruments on the Consolidated Statements of Operations
Gain/(Loss) recognized in Interest Income and Other Income/(Expense), net	$ 0	$ 0

DERIVATIVES AND HEDGING ACTIV_6

DERIVATIVES AND HEDGING ACTIVITY - Effectiveness (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivatives and hedging activity
Estimated additional accumulated other comprehensive Income/(Loss) transferred to interest expense	$ 4,600
Total amount of Interest expense presented on the Consolidated Statements of Operations	39,317	$ 33,542
Interest rate swaps | Designated as Hedging Instrument
Fair value
Notional	$ 315,000

DERIVATIVES AND HEDGING ACTIV_7

DERIVATIVES AND HEDGING ACTIVITY - Offsetting Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Offsetting derivative assets
Net Amounts of Assets Presented in the Consolidated Balance Sheets (a)		$ 6
Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments		(3)
Net Amount		3
Offsetting derivative liabilities
Gross Amounts of Recognized Liabilities	$ 3,075	142
Net Amounts of Liabilities Presented in the Consolidated Balance Sheets (b)	3,075	142
Gross Amounts Not Offset in the Consolidated Balance Sheets, Financial Instruments		(3)
Net Amount	$ 3,075	$ 139

STOCK BASED COMPENSATION (Detai

STOCK BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2020
Stock based compensation
Stock based compensation expense	$ 6.8	$ 5.9	$ 6.8

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)community	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Real estate properties
Development costs and capital expenditures incurred but not yet paid	$ 25,568	$ 10,745
Number of communities owned (in communities) | community	150
Costs Incurred to Date	$ 161,997
UDR's Remaining Commitment	$ 229,062
King of Prussia
Real estate properties
Contractual purchase price commitment			$ 14,800
Deposit on purchase			$ 800
Wholly owned - under development
Real estate properties
Number of communities owned (in communities) | community	3
Costs Incurred to Date	$ 95,326
UDR's Remaining Commitment	$ 183,174
Wholly owned - redevelopment
Real estate properties
Number of communities owned (in communities) | community	2
Costs Incurred to Date	$ 17,660
UDR's Remaining Commitment	$ 7,840
Preferred Equity Investments
Real estate properties
Number of communities owned (in communities) | community	2
Costs Incurred to Date	$ 34,647
UDR's Remaining Commitment	14,348
Other investments
Real estate properties
Costs Incurred to Date	14,364
UDR's Remaining Commitment	$ 23,700

REPORTABLE SEGMENTS (Details)

REPORTABLE SEGMENTS (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)segment	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)item	Mar. 31, 2020USD ($)home	Mar. 31, 2019USD ($)item	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segments
Same store communities					37,910	37,910	37,910
Reportable Segments
Number of reportable segments | segment		2
Condition for Community considered to have stabilized occupancy	90%
Time to maintain percent occupancy to be considered a community	3 months
Practical expedient, single lease component	true
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Rental income				$ 320,093			$ 267,922
Reconciling items:
Joint venture management and other fees				1,388			$ 2,751
Type of revenue	udr:ManagementAndOtherFeesMember						udr:ManagementAndOtherFeesMember
Property management				(9,203)			$ (7,703)
Other operating expenses				(4,966)			(5,646)
Real estate depreciation and amortization				(155,476)			(112,468)
General and administrative				(14,978)			(12,467)
Casualty-related (charges)/recoveries, net				(1,251)
Other depreciation and amortization				(2,025)			(1,656)
Income/(loss) from unconsolidated entities				3,367			49
Interest expense				(39,317)			(33,542)
Interest and other income/(expense), net				2,700			9,813
Tax (provision)/benefit, net				(164)			(2,212)
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership				(313)			(2,057)
Net (income)/loss attributable to noncontrolling interests				(6)			(42)
Net income/(loss) attributable to UDR, Inc.				5,221			24,503
Reportable apartment home segment assets:
Total segment assets	$ 12,817,998	$ 12,817,998	$ 12,817,998	12,817,998	$ 12,817,998	$ 12,817,998		$ 12,602,101
Accumulated depreciation	(4,272,471)	(4,272,471)	(4,272,471)	(4,272,471)	(4,272,471)	(4,272,471)		(4,131,353)
Total real estate owned, net of accumulated depreciation	8,545,527	8,545,527	8,545,527	8,545,527	8,545,527	8,545,527		8,470,748
Reconciling items:
Cash and cash equivalents	980	980	980	980	980	980	1,043	8,106	$ 185,216
Restricted cash	21,949	21,949	21,949	21,949	21,949	21,949	23,111	25,185	$ 23,675
Notes receivable, net	151,543	151,543	151,543	151,543	151,543	151,543		153,650
Investment in and advances to unconsolidated joint ventures, net	588,395	588,395	588,395	588,395	588,395	588,395		588,262
Operating lease right-of-use assets	203,410	203,410	203,410	203,410	203,410	203,410		204,225
Other assets	179,301	179,301	179,301	179,301	179,301	179,301		186,296
Total consolidated assets	9,691,105	9,691,105	9,691,105	9,691,105	9,691,105	9,691,105		9,636,472
Same Store Communities West Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				102,616			98,633
Other revenue				2,774			3,076
Rental income				105,390			101,709
Reportable apartment home segment NOI				79,823			76,984
Reportable apartment home segment assets:
Total segment assets	3,704,480	3,704,480	3,704,480	3,704,480	3,704,480	3,704,480		3,696,544
Same Store Communities Mid-Atlantic Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				56,085			54,300
Other revenue				1,573			2,002
Rental income				57,658			56,302
Reportable apartment home segment NOI				40,377			39,179
Reportable apartment home segment assets:
Total segment assets	2,356,688	2,356,688	2,356,688	2,356,688	2,356,688	2,356,688		2,350,341
Same Store Communities Northeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				30,942			30,193
Other revenue				501			629
Rental income				31,443			30,822
Reportable apartment home segment NOI				20,614			20,977
Reportable apartment home segment assets:
Total segment assets	1,501,767	1,501,767	1,501,767	1,501,767	1,501,767	1,501,767		1,500,597
Same Store Communities Southeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				30,677			29,531
Other revenue				1,429			1,790
Rental income				32,106			31,321
Reportable apartment home segment NOI				22,617			22,010
Reportable apartment home segment assets:
Total segment assets	810,984	810,984	810,984	810,984	810,984	810,984		806,830
Same Store Communities Southwest Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				16,626			16,077
Other revenue				590			763
Rental income				17,216			16,840
Reportable apartment home segment NOI				11,056			10,328
Reportable apartment home segment assets:
Total segment assets	603,082	603,082	603,082	603,082	603,082	603,082		600,350
Non-Mature communities/Other
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				74,676			30,169
Other revenue				1,604			759
Rental income				76,280			30,928
Reportable apartment home segment NOI				50,978			20,205
Reportable apartment home segment assets:
Total segment assets	$ 3,840,997	$ 3,840,997	$ 3,840,997	3,840,997	$ 3,840,997	$ 3,840,997		$ 3,647,439
Total Communities
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				311,622			258,903
Other revenue				8,471			9,019
Rental income				320,093			267,922
Reportable apartment home segment NOI				$ 225,465			$ 189,683
Taxable REIT Subsidiaries
Reportable Segments
Management fee (as a percent)			2.875%

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNITED DOMINION REALTY, L.P.) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned:
Real estate held for investment	$ 12,608,022	$ 12,532,324
Less: accumulated depreciation	(4,231,269)	(4,131,330)
Real estate held for disposition (net of accumulated depreciation of $41,121 and $0, respectively)	73,529
Total real estate owned, net of accumulated depreciation	8,545,527	8,470,748
Cash and cash equivalents	980	8,106
Restricted cash	21,949	25,185
Investment in unconsolidated entities	585,091	585,490
Operating lease right-of-use assets	203,410	204,225
Other assets	179,301	186,296
Total assets	9,691,105	9,636,472
LIABILITIES AND CAPITAL
Secured debt, net	1,144,201	1,149,441
Operating lease liabilities	197,829	198,558
Real estate taxes payable	33,134	29,445
Accrued interest payable	31,494	45,199
Security deposits and prepaid rent	48,474	48,353
Distributions payable	115,259	109,382
Accounts payable, accrued expenses, and other liabilities	82,254	90,032
Total liabilities	5,393,582	5,228,493
Commitments and contingencies (Note 11)
Partners' capital:
Total liabilities and equity	9,691,105	9,636,472
United Dominion Realty L.P.
Real estate owned:
Real estate held for investment	3,886,613	3,875,160
Less: accumulated depreciation	(1,831,814)	(1,796,568)
Total real estate owned, net of accumulated depreciation	2,054,799	2,078,592
Cash and cash equivalents	40	24
Restricted cash	14,121	13,998
Investment in unconsolidated entities	69,617	76,222
Operating lease right-of-use assets	204,723	205,668
Other assets	24,042	24,241
Total assets	2,367,342	2,398,745
LIABILITIES AND CAPITAL
Secured debt, net	99,082	99,071
Notes payable due to the General Partner	635,738	637,233
Operating lease liabilities	199,149	200,001
Real estate taxes payable	8,639	2,801
Accrued interest payable	219	217
Security deposits and prepaid rent	17,854	17,946
Distributions payable	66,833	63,364
Accounts payable, accrued expenses, and other liabilities	10,426	12,226
Total liabilities	1,037,940	1,032,859
Commitments and contingencies (Note 11)
Partners' capital:
General partner: 110,883 OP Units outstanding at March 31, 2020 and December 31, 2019	833	859
184,724,677 and 183,952,659 OP Units outstanding at March 31, 2020 and December 31, 2019, respectively	1,310,642	1,347,622
Total partners' capital	1,311,475	1,348,481
Noncontrolling interests	17,927	17,405
Total capital	1,329,402	1,365,886
Total liabilities and equity	$ 2,367,342	$ 2,398,745

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (UNITED DOMINION REALTY, L.P.) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned:
Real estate held for disposition accumulated depreciation	$ 41,121	$ 0
Partners' capital:
Operating Partnership units outstanding related to limited partner	184,836,000	184,064,000
United Dominion Realty L.P.
Partners' capital:
OP units outstanding related to general partner	110,883	110,883
Operating Partnership units outstanding related to limited partner	184,724,677	183,952,659

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (UNITED DOMINION REALTY, L.P.) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
REVENUES:
Rental income	$ 320,093	$ 267,922
OPERATING EXPENSES:
Property operating and maintenance	49,483	41,939
Real estate taxes and insurance	45,145	36,300
Property management	9,203	7,703
Other operating expenses	4,966	5,646
Real estate depreciation and amortization	155,476	112,468
General and administrative	14,978	12,467
Casualty-related charges/(recoveries), net	1,251
Total operating expenses	282,527	218,179
Operating income	38,954	52,494
Income/(loss) from unconsolidated entities	3,367	49
Interest expense	(39,317)	(33,542)
Net income/(loss)	5,540	26,602
United Dominion Realty L.P.
REVENUES:
Rental income	112,165	108,334
OPERATING EXPENSES:
Property operating and maintenance	16,837	16,531
Real estate taxes and insurance	13,773	12,664
Property management	3,225	2,979
Other operating expenses	3,859	2,400
Real estate depreciation and amortization	35,300	34,654
General and administrative	5,308	4,661
Casualty-related charges/(recoveries), net	(2)
Total operating expenses	78,300	73,889
Operating income	33,865	34,445
Income/(loss) from unconsolidated entities	(1,761)	(2,740)
Interest expense	(742)	(190)
Interest expense on notes payable due to the General Partner	(6,722)	(7,181)
Net income/(loss)	24,640	24,334
Net (income)/loss attributable to noncontrolling interests	(522)	(388)
Net income/(loss) attributable to OP unitholders	$ 24,118	$ 23,946
Income/(loss) per OP unit- basic and diluted:
Net income/(loss) per weighted average OP Unit - basic and diluted	$ 0.13	$ 0.13
Weighted average OP Units outstanding - basic and diluted	184,503	183,949

CONSOLIDATED STATEMENTS OF CH_3

CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL (UNITED DOMINION REALTY, L.P.) (Unaudited). - United Dominion Realty L.P. - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Beginning Balance	$ 1,365,886	$ 1,485,889
Net income/(loss)	24,640	24,334
Distributions	(66,658)	(63,469)
Long Term Incentive Plan Unit grants	5,534	10,032
Ending Balance	1,329,402	1,456,786
Total Partner's Capital
Beginning Balance	1,348,481	1,472,070
Net income/(loss)	24,118	23,946
Distributions	(66,658)	(63,469)
Long Term Incentive Plan Unit grants	5,534	10,032
Ending Balance	1,311,475	1,442,579
Noncontrolling Interests
Beginning Balance	17,405	13,819
Net income/(loss)	522	388
Ending Balance	17,927	14,207
Class A Limited Partner
Beginning Balance	81,803	69,401
Net income/(loss)	229	228
Distributions	(631)	(599)
Adjustment to reflect limited partners' capital at redemption value	(17,395)	10,601
Ending Balance	64,006	79,631
Limited Partners and LTIP Units
Beginning Balance	284,580	302,545
Net income/(loss)	896	812
Distributions	(2,588)	(2,570)
OP Unit redemptions for common shares of UDR		(71,673)
Adjustment to reflect limited partners' capital at redemption value	(37,545)	44,716
Long Term Incentive Plan Unit grants	5,534	10,032
Ending Balance	250,877	283,862
Limited Partner
Beginning Balance	981,239	1,099,174
Net income/(loss)	22,979	22,892
Distributions	(63,399)	(60,262)
OP Unit redemptions for common shares of UDR		71,673
Adjustment to reflect limited partners' capital at redemption value	54,940	(55,317)
Ending Balance	995,759	1,078,160
General Partner
Beginning Balance	859	950
Net income/(loss)	14	14
Distributions	(40)	(38)
Ending Balance	$ 833	$ 926

CONSOLIDATED STATEMENTS OF CA_4

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNITED DOMINION REALTY, L.P.) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net income/(loss)	$ 5,540	$ 26,602
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:
Depreciation and amortization	157,501	114,124
(Income)/loss from unconsolidated entities	(3,367)	(49)
Other	(1,215)	3,910
Changes in operating assets and liabilities:
(Increase)/decrease in operating assets	114	2,295
Increase/(decrease) in operating liabilities	(31,666)	(17,463)
Net cash provided by/(used in) operating activities	135,456	137,333
Investing Activities
Acquisition of real estate assets	(141,727)	(403,245)
Capital expenditures and other major improvements - real estate assets	(32,983)	(31,264)
Distributions received from unconsolidated entities	3,271	10,797
Net cash provided by/(used in) investing activities	(214,044)	(459,749)
Financing Activities
Payments on secured debt	(2,781)	(962)
Other	(3,964)	1,706
Net cash provided by/(used in) financing activities	68,226	137,679
Net increase/(decrease) in cash, cash equivalents, and restricted cash	(10,362)	(184,737)
Cash, cash equivalents, and restricted cash, beginning of year	33,291	208,891
Cash, cash equivalents, and restricted cash, end of period	22,929	24,154
Supplemental Information:
Interest paid during the period, net of amounts capitalized	57,320	44,271
Non-cash transactions:
Development costs and capital expenditures incurred but not yet paid	25,568	10,745
Recognition of operating lease liabilities		88,336
Dividends declared but not yet paid	115,259	105,548
United Dominion Realty L.P.
Operating Activities
Net income/(loss)	24,640	24,334
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:
Depreciation and amortization	35,300	34,654
(Income)/loss from unconsolidated entities	1,761	2,740
Other	880	1,364
Changes in operating assets and liabilities:
(Increase)/decrease in operating assets	(500)	2,529
Increase/(decrease) in operating liabilities	3,324	3,006
Net cash provided by/(used in) operating activities	65,405	68,627
Investing Activities
Capital expenditures and other major improvements - real estate assets	(10,960)	(14,271)
Distributions received from unconsolidated entities	4,844	4,613
Net cash provided by/(used in) investing activities	(6,116)	(9,658)
Financing Activities
Issuance/(repayment) of notes payable to the General Partner	(56,497)	(55,599)
Distributions paid to partnership unitholders	(2,653)	(2,989)
Net cash provided by/(used in) financing activities	(59,150)	(58,588)
Net increase/(decrease) in cash, cash equivalents, and restricted cash	139	381
Cash, cash equivalents, and restricted cash, beginning of year	14,022	13,688
Cash, cash equivalents, and restricted cash, end of period	14,161	14,069
Supplemental Information:
Interest paid during the period, net of amounts capitalized	10,665	5,031
Non-cash transactions:
Development costs and capital expenditures incurred but not yet paid	3,383	3,676
Recognition of operating lease right-of-use assets		94,174
Recognition of operating lease liabilities		88,161
LTIP Unit grants	5,534	10,032
Dividends declared but not yet paid	$ 66,833	$ 63,451

CONSOLIDATED STATEMENTS OF CA_5

CONSOLIDATED STATEMENTS OF CASH FLOWS - SUPPLEMENTAL (UNITED DOMINION REALTY, L.P.) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
The following reconciles cash, cash equivalents, and restricted cash to the total of the same amounts as shown above:
Cash and cash equivalents	$ 980	$ 8,106	$ 1,043	$ 185,216
Restricted cash	21,949	25,185	23,111	23,675
Total cash, cash equivalents, and restricted cash as shown above	22,929	33,291	24,154	208,891
United Dominion Realty L.P.
The following reconciles cash, cash equivalents, and restricted cash to the total of the same amounts as shown above:
Cash and cash equivalents	40	24	59	125
Restricted cash	14,121	13,998	14,010	13,563
Total cash, cash equivalents, and restricted cash as shown above	$ 14,161	$ 14,022	$ 14,069	$ 13,688

CONSOLIDATION AND BASIS OF PRES

CONSOLIDATION AND BASIS OF PRESENTATION (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
CONSOLIDATION AND BASIS OF PRESENTATION	1. BASIS OF PRESENTATION Basis of Presentation UDR, Inc., collectively with our consolidated subsidiaries (“UDR,” the “Company,” “we,” “our,” or “us”), is a self-administered real estate investment trust, or REIT, that owns, operates, acquires, renovates, develops, redevelops, and manages apartment communities. The accompanying consolidated financial statements include the accounts of UDR and its subsidiaries, including United Dominion Realty, L.P. (the “Operating Partnership” or the “OP”) and UDR Lighthouse DownREIT L.P. (the “DownREIT Partnership”). As of March 31, 2020, there were 184.8 million units in the Operating Partnership (“OP Units”) outstanding, of which 176.2 million OP Units (including 0.1 million of general partnership units), or 95.3%, were owned by UDR and 8.6 million OP Units, or 4.7%, were owned by outside limited partners. As of March 31, 2020, there were 32.4 million units in the DownREIT Partnership (“DownREIT Units”) outstanding, of which 18.6 million, or 57.4%, were owned by UDR (including 13.5 million DownREIT Units, or 41.6%, that were held by the Operating Partnership) and 13.8 million, or 42.6%, were owned by outside limited partners. The consolidated financial statements of UDR include the noncontrolling interests of the unitholders in the Operating Partnership and DownREIT Partnership. The accompanying interim unaudited consolidated financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission. Certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted according to such rules and regulations, although management believes that the disclosures are adequate to make the information presented not misleading. In the opinion of management, all adjustments and eliminations necessary for the fair presentation of our financial position as of March 31, 2020, and results of operations for the three months ended March 31, 2020 and 2019, have been included. Such adjustments are normal and recurring in nature. The interim results presented are not necessarily indicative of results that can be expected for a full year, particularly in light of the novel coronavirus disease (“COVID-19”) pandemic and measures intended to mitigate its spread. The accompanying interim unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes for the year ended December 31, 2019 appearing in UDR’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 18, 2020. The accompanying interim unaudited consolidated financial statements are presented in accordance with U.S. generally accepted accounting principles (“GAAP”). GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the dates of the interim unaudited consolidated financial statements and the amounts of revenues and expenses during the reporting periods. Actual amounts realized or paid could differ from those estimates. All significant intercompany accounts and transactions have been eliminated in consolidation. The Company evaluated subsequent events through the date its financial statements were issued. No significant recognized or non-recognized subsequent events were noted other than those noted in Note 2, Significant Accounting Policies, , Real Estate Owned, Secured and Unsecured Debt, Net Subsequent Event
United Dominion Realty L.P.
Entity information
CONSOLIDATION AND BASIS OF PRESENTATION	1. CONSOLIDATION AND BASIS OF PRESENTATION Basis of Presentation United Dominion Realty, L.P. (“UDR, L.P.,” the “Operating Partnership,” “we” or “our”) is a Delaware limited partnership, that owns, acquires, renovates, redevelops, manages, and disposes of multifamily apartment communities generally located in high barrier to entry markets located in the United States. The high barrier to entry markets are characterized by limited land for new construction, difficult and lengthy entitlement process, expensive single-family home prices and significant employment growth potential. UDR, L.P. is a subsidiary of UDR, Inc. (“UDR” or the “General Partner”), a self-administered real estate investment trust, or REIT, through which UDR conducts a significant portion of its business. During the three months ended March 31, 2020 and 2019, rental revenues of the Operating Partnership represented 35% and 40%, respectively, of the General Partner’s consolidated rental revenues. As of March 31, 2020, the Operating Partnership’s apartment portfolio consisted of 52 communities located in 15 markets consisting of 16,434 apartment homes. Interests in UDR, L.P. are represented by operating partnership units (“OP Units”). The Operating Partnership’s net income is allocated to the partners, which is initially based on their respective distributions made during the year and secondly, their percentage interests. Distributions are made in accordance with the terms of the Amended and Restated Agreement of Limited Partnership of United Dominion Realty, L.P. (the “Operating Partnership Agreement”), on a per unit basis that is generally equal to the dividend per share on UDR’s common stock, which is publicly traded on the New York Stock Exchange (“NYSE”) under the ticker symbol “UDR.” As of March 31, 2020, there were 184.8 million OP Units outstanding, of which 176.2 million, or 95.3%, were owned by UDR and affiliated entities and 8.6 million, or 4.7%, were owned by non-affiliated limited partners. There were 184.1 million OP Units outstanding as of December 31, 2019, of which 176.2 million, or 95.7%, were owned by UDR and affiliated entities and 7.9 million, or 4.3%, were owned by non-affiliated limited partners. See Note 10, Capital Structure The accompanying interim unaudited consolidated financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted according to such rules and regulations, although management believes that the disclosures are adequate to make the information presented not misleading. In the opinion of management, all adjustments and eliminations necessary for the fair presentation of our financial position as of March 31, 2020, and results of operations for the three months ended March 31, 2020 and 2019, have been included. Such adjustments are normal and recurring in nature. The interim results presented are not necessarily indicative of results that can be expected for a full year, particularly in light of the novel coronavirus disease (“COVID-19”) pandemic and measures intended to mitigate its spread. The accompanying interim unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes for the year ended December 31, 2019 included in the Annual Report on Form 10-K filed by UDR and the Operating Partnership with the SEC on February 18, 2020. The accompanying interim unaudited consolidated statements are presented in accordance with U.S. generally accepted accounting principles (“GAAP”). GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the dates of the interim unaudited consolidated financial statements and the amounts of revenues and expenses during the reporting periods. Actual amounts realized or paid could differ from those estimates. All intercompany accounts and transactions have been eliminated in consolidation. The Operating Partnership evaluated subsequent events through the date its financial statements were issued. No significant recognized or non-recognized subsequent events were noted other than those noted in Note 6, Debt, net Subsequent Event.

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
SIGNIFICANT ACCOUNTING POLICIES	2. SIGNIFICANT ACCOUNTING POLICIES Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, basis through a cumulative-effect adjustment to retained earnings of approximately $2.2 million on that date, which was primarily associated with our notes receivable. The Company concluded the cumulative effect was not material to our consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) ​ Principles of Consolidation The Company accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Company first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Company consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest. Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Company generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Company will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Company sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Company will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Company will record a full gain or loss in the period the property is contributed. ​ To the extent that the Company acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Company will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Company will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Company will not recognize a gain or loss on consolidation of a property. ​ Allowance for Credit Losses The Company accounts for allowance for credit losses under the current expected credit loss (“CECL”) impairment model for its financial assets, including trade and other receivables, held-to-maturity debt securities, loans and other financial instruments, and presents the net amount of the financial instrument expected to be collected. The CECL impairment model excludes operating lease receivables. The CECL impairment model requires an estimate of expected credit losses, measured over the contractual life of an instrument, that considers forecasts of future economic conditions in addition to information about past events and current conditions. Based on this model, we analyze the following criteria, as applicable in developing allowances for credit losses: historical loss information, the borrower’s ability to make scheduled payments, the remaining time to maturity, the value of underlying collateral, projected future performance of the borrower and macroeconomic trends. ​ The Company measures credit losses of financial assets on a collective (pool) basis when similar risk characteristics exist. If the Company determines that a financial asset does not share risk characteristics with its other financial assets, the Company evaluates the financial asset for expected credit losses on an individual basis. Allowance for credit losses are recorded as a direct reduction from an asset’s amortized cost basis. Credit losses and recoveries are recorded in Interest income and other income/(expense), net ​ The Company has made the optional election provided by the standard not to measure allowance for credit losses for accrued interest receivables as the Company writes off any uncollectible accrued interest receivables in a timely manner. The Company periodically evaluates the collectability of its accrued interest receivables. A write-off is recorded when the Company concludes that all or a portion of its accrued interest receivable balance is no longer collectible. ​ Notes Receivable Notes receivable relate to financing arrangements which are typically secured by real estate, real estate related projects or other assets. Certain of the loans we extend may include characteristics such as options to purchase the project within a specific time window following expected project completion. These characteristics can cause the loans to fall under the definition of a VIE, and thus trigger consolidation consideration. We consider the facts and circumstances pertinent to each loan, including the relative amount of financing we are contributing to the overall project cost, decision making rights or control we hold, and our rights to expected residual gains or our obligations to absorb expected residual losses from the project. If we are deemed to be the primary beneficiary of a VIE due to holding a controlling financial interest, the majority of decision making control, or by other means, consolidation of the VIE would be required. The Company has concluded that it is not the primary beneficiary of the borrowing entities which were deemed to be VIEs. Additionally, we analyze each loan arrangement that involves real estate development to consider whether the loan qualifies for accounting as a loan or as an investment in a real estate development project. The Company has evaluated its real estate loans, where appropriate, for accounting treatment as loans versus real estate development projects, as required by ASC 310-10. For each loan, the Company has concluded that the characteristics and the facts and circumstances indicate that loan accounting treatment is appropriate. The following table summarizes our Notes receivable, net dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due April 2020 (a) 12.00 % $ 20,000 ​ $ 20,000 Note due October 2020 (b) 8.00 % — ​ 2,250 Note due October 2022 (c) 4.75 % 115,000 ​ 115,000 Note due January 2023 (d) ​ 10.00 % ​ 17,300 ​ ​ 16,400 Notes Receivable ​ ​ ​ ​ 152,300 ​ ​ 153,650 Allowance for credit losses ​ ​ ​ ​ (757) ​ ​ — Total notes receivable, net ​ $ 151,543 ​ $ 153,650 (a) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, all of which has been funded. The note is secured by a parcel of land and related land improvements. Interest payments up to December 2019 are due when the loan matures and interest payments after December 2019 are due monthly. In April 2020, the terms of the secured note were amended to extend the term to May 30, 2022, to adjust the interest rate to 8.0% and to add some covenants of the Borrower. (b) In March 2020, the Company entered into a purchase agreement to acquire all of the unaffiliated third party’s intellectual property in exchange for cancellation of the secured note and accrued interest. All property acquired was recorded in Other assets on the Consolidated Balance Sheets. (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $115.0 million, all of which has been funded. Interest payments are due when the loan matures. The note is secured by a first priority deed of trust on an under construction 259 apartment home operating community in Bellevue, Washington, which is expected to be completed in 2020. When the note was funded, the Company also entered into a purchase option agreement and paid a deposit of $10.0 million, which gives the Company the option to acquire the community at a fixed price of $170.0 million. The purchase option must be exercised within 30 days following the date the temporary certificate of occupancy for the residential portion of the project is issued. The deposit is generally nonrefundable other than due to a failure of closing conditions pursuant to the terms of the agreement. If the Company does not exercise the purchase option, or if the Company exercises and fails to close the purchase other than due to seller’s failure or other breaches in the purchase option agreement, per the terms of the agreement, the note will be modified to extend the maturity date to 10 years following the date the temporary certificate of occupancy is issued. Upon modification, the loan will be interest only for the first three years and after such date payments will be based on a 30-year amortization schedule. (d) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $20.0 million, of which $17.3 million has been funded, including $0.9 million funded during the three months ended March 31, 2020. Interest payments are due monthly. The note matures at the earliest of the following: (a) the closing of any private or public capital raising in the amount of $5.0 million or greater; (b) an acquisition; (c) acceleration in the event of default; or (d) January 2023. During 2020, the terms of this secured note were amended to increase the aggregate commitment from $16.4 million to $20.0 million, to extend the maturity date of the note to January 2023 and for the April 2020 through July 2020 interest payments to be deferred and paid when the note matures The Company recognized $2.6 million and $1.1 million of interest income for the notes receivable described above during the three months ended March 31, 2020 and 2019, respectively, none of which was related party interest. Interest income is included in Interest income and other income/(expense), net Comprehensive Income/(Loss) Comprehensive income/(loss), which is defined as the change in equity during each period from transactions and other events and circumstances from nonowner sources, including all changes in equity during a period except for those resulting from investments by or distributions to stockholders, is displayed in the accompanying Consolidated Statements of Comprehensive Income/(Loss). For the three months ended March 31, 2020 and 2019, the Company’s other comprehensive income/(loss) consisted of the gain/(loss) on derivative instruments that are designated as and qualify as cash flow hedges, (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) into earnings, and the allocation of other comprehensive income/(loss) to noncontrolling interests. The (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) is included in Interest expense Derivatives and Hedging Activity, Income Taxes Due to the structure of the Company as a REIT and the nature of the operations for the operating properties, no provision for federal income taxes has been provided for at UDR. Historically, the Company has generally incurred only state and local excise and franchise taxes. UDR has elected for certain consolidated subsidiaries to be treated as taxable REIT subsidiaries (“TRS”). Income taxes for our TRS are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rate is recognized in earnings in the period of the enactment date. The Company’s deferred tax assets/(liabilities) are generally the result of differing depreciable lives on capitalized assets, temporary differences between book and tax basis of assets and liabilities and timing of expense recognition for certain accrued liabilities. As of March 31, 2020 and December 31, 2019, UDR’s net deferred tax asset/(liability) was $(1.4) million and $(1.6) million, respectively. GAAP defines a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. GAAP also provides guidance on derecognition, classification, interest and penalties, accounting for interim periods, disclosure and transition. The Company recognizes its tax positions and evaluates them using a two-step process. First, UDR determines whether a tax position is more likely than not (greater than 50 percent probability) to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. Second, the Company will determine the amount of benefit to recognize and record the amount that is more likely than not to be realized upon ultimate settlement. The Company invests in assets that qualify for federal investment tax credits (“ITC”) through our TRS. An ITC reduces federal income taxes payable when qualifying depreciable property is acquired. The ITC is determined as a percentage of cost of the assets. The Company accounts for ITCs under the deferral method, under which the tax benefit from the ITC is deferred and amortized as a tax benefit into Tax (provision)/benefit, net Accounts payable, accrued expenses and other liabilities UDR had no material unrecognized tax benefit, accrued interest or penalties at March 31, 2020. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2016 through 2018 remain open to examination by tax jurisdictions to which we are subject. When applicable, UDR recognizes interest and/or penalties related to uncertain tax positions in Tax (provision)/benefit, net ​ Forward Sales Agreements ​ The Company utilizes forward sales agreements for the future issuance of its common stock. When the Company enters into a forward sales agreement, the contract requires the Company to sell its shares to a counterparty at a predetermined price at a future date. The net sales price and proceeds attained by the Company will be determined on the dates of settlement, with adjustments during the term of the contract for the Company’s anticipated dividends as well as for a daily interest factor that varies with changes in the federal funds rate. The Company generally has the ability to determine the dates and method of settlement (i.e., gross physical settlement, net share settlement or cash settlement), subject to certain conditions and the right of the counterparty to accelerate settlement under certain circumstances. ​ The Company accounts for the shares of common stock reserved for issuance upon settlement as equity in accordance with ASC 815-40, Contracts in Entity's Own Equity ​ The guidance establishes a two-step process for evaluating whether an equity-linked financial instrument is considered indexed to its own stock, first, evaluating the instrument’s contingent exercise provisions and second, evaluating the instrument’s settlement provisions. When entering into forward sales agreements, we determined that (i) none of the agreement’s exercise contingencies are based on observable markets or indices besides those related to the market for our own stock price; and (ii) none of the settlement provisions preclude the agreements from being indexed to our own stock. ​ Before the issuance of shares of common stock, upon physical or net share settlement of the forward sales agreements, the Company expects that the shares issuable upon settlement of the forward sales agreements will be reflected in its diluted income/(loss) per share calculations using the treasury stock method. Under this method, the number of shares of common stock used in calculating diluted income/(loss) per share is deemed to be increased by the excess, if any, of the number of shares of common stock that would be issued upon full physical settlement of the forward sales agreements over the number of shares of common stock that could be purchased by the Company in the open market (based on the average market price during the period) using the proceeds receivable upon full physical settlement (based on the adjusted forward sale price at the end of the reporting period). When the Company physically or net share settles any forward sales agreement, the delivery of shares of common stock would result in an increase in the number of weighted average common shares outstanding and dilution to basic income/(loss) per share. (See Note 8, Income/(Loss) per Share
United Dominion Realty L.P.
Entity information
SIGNIFICANT ACCOUNTING POLICIES	2. SIGNIFICANT ACCOUNTING POLICIES Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, updated standard became effective for the Operating Partnership on January 1, 2020 and was adopted on a modified retrospective basis. However, as the Operating Partnership’s financial assets primarily relate to receivables arising from operating leases, the ASU did not have a material impact on the consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) ​ Principles of Consolidation The Operating Partnership accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Operating Partnership first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Operating Partnership consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Operating Partnership consolidates an entity when it controls the entity through ownership of a majority voting interest. Income/(Loss) Per Operating Partnership Unit Basic income/(loss) per OP Unit is computed by dividing net income/(loss) attributable to the general and limited partner unitholders by the weighted average number of general and limited partner units outstanding during the year. Diluted income/(loss) per OP Unit reflects the potential dilution that could occur if securities or other contracts to issue OP Units were exercised or converted into OP Units or resulted in the issuance of OP Units and then shared in the income/(loss) of the Operating Partnership. Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Operating Partnership generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Operating Partnership will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Operating Partnership sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Operating Partnership will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Operating Partnership will record a full gain or loss in the period the property is contributed. ​ To the extent that the Operating Partnership acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Operating Partnership will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Operating Partnership will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Operating Partnership will not recognize a gain or loss on consolidation of a property. ​ Income Taxes The taxable income or loss of the Operating Partnership is reported on the tax returns of the partners. Accordingly, no provision has been made in the accompanying financial statements for federal or state income taxes on income that is passed through to the partners. However, any state or local revenue, excise or franchise taxes that result from the operating activities of the Operating Partnership are recorded at the entity level. The Operating Partnership’s tax returns are subject to examination by federal and state taxing authorities. Net income for financial reporting purposes differs from the net income for income tax reporting purposes primarily due to temporary differences, principally real estate depreciation and the tax deferral of certain gains on property sales. The differences in depreciation result from differences in the book and tax basis of certain real estate assets and the differences in the methods of depreciation and lives of the real estate assets. The Operating Partnership evaluates the accounting and disclosure of tax positions taken or expected to be taken in the course of preparing the Operating Partnership’s tax returns to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. Tax positions not deemed to meet the more-likely-than-not threshold would be recorded as a tax benefit or expense in the current year. Management of the Operating Partnership is required to analyze all open tax years, as defined by the statute of limitations, for all major jurisdictions, which include federal and certain states. The Operating Partnership has no examinations in progress and none are expected at this time. Management of the Operating Partnership has reviewed all open tax years (2016 through 2018) of tax jurisdictions and concluded there is no tax liability resulting from unrecognized tax benefits relating to uncertain income tax positions taken or expected to be taken in future tax returns. ​

REAL ESTATE OWNED (UNITED DOMIN

REAL ESTATE OWNED (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
REAL ESTATE OWNED	3. REAL ESTATE OWNED Real estate assets owned by the Company consist of income producing operating properties, properties under development, land held for future development, and held for disposition properties. As of March 31, 2020, the Company owned and consolidated 150 communities in 13 states plus the District of Columbia totaling 47,579 apartment homes. The following table summarizes the carrying amounts for our real estate owned (at cost) as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 2,163,055 ​ $ 2,164,032 Depreciable property — held and used: ​ ​ Land improvements ​ 225,850 ​ 224,964 Building, improvements, and furniture, fixtures and equipment ​ 10,178,547 ​ 10,102,758 Real estate intangible assets ​ ​ 40,570 ​ ​ 40,570 Under development: ​ ​ Land and land improvements ​ 29,226 ​ 29,226 Building, improvements, and furniture, fixtures and equipment ​ 66,100 ​ 40,551 Real estate held for disposition: ​ ​ Land and land improvements ​ 16,245 ​ — Building, improvements, and furniture, fixtures and equipment ​ 98,405 ​ — Real estate owned ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Real estate owned, net ​ $ 8,545,527 ​ $ 8,470,748 ​ Acquisitions In January 2020, the Company acquired a 294 apartment home operating community located in Tampa, Florida for approximately $85.2 million. The Company increased its real estate assets owned by approximately $83.1 million and recorded approximately $2.1 million of in-place lease intangibles. In January 2020, the Company increased its ownership interest from 49% to 100% in a 276 apartment home operating community located in Hillsboro, Oregon, for a cash purchase price of approximately $21.6 million. In connection with the acquisition, the Company repaid approximately $35.6 million of joint venture construction financing. As a result, the Company consolidated the operating community. The Company had previously accounted for its 49% ownership interest as a preferred equity investment in an unconsolidated joint venture (see Note 5, Joint Ventures and Partnerships no ​ Dispositions ​ In March 2020, the Company received a nonrefundable deposit on the pending sale of an operating community located in Seattle, Washington. The asset is included in Real estate held for disposition Sheet as of March 31, 2020. The sale is expected to close in the second quarter of 2020 at a gross sales price of $49.7 million. In May 2020, the Company sold an operating community in Seattle, Washington with a total of 196 apartment homes for gross proceeds of $92.9 million, resulting in a gain of approximately $31.7 million. The asset is included in Real estate held for disposition Other Activity Predevelopment, development, and redevelopment projects and related costs are capitalized and reported on the Consolidated Balance Sheets as Total real estate owned, net of accumulated depreciation In connection with the acquisition of certain properties, the Company agreed to pay certain of the tax liabilities of certain contributors if the Company sells one or more of the properties contributed in a taxable transaction prior to the expiration of specified periods of time following the acquisition. The Company may, however, sell, without being required to pay any tax liabilities, any of such properties in a non-taxable transaction, including, but not limited to, a tax-deferred Section 1031 exchange. Further, the Company has agreed to maintain certain debt that may be guaranteed by certain contributors for specified periods of time following the acquisition. The Company, however, has the ability to refinance or repay guaranteed debt or to substitute new debt if the debt and the guaranty continue to satisfy certain conditions.
United Dominion Realty L.P.
Entity information
REAL ESTATE OWNED	3. REAL ESTATE OWNED Real estate assets owned by the Operating Partnership consist of income producing operating properties, properties under development, land held for future development, and sold or held for disposition properties. At March 31, 2020, the Operating Partnership owned and consolidated 52 communities in nine states plus the District of Columbia totaling 16,434 apartment homes. The following table summarizes the carrying amounts for our real estate owned (at cost) as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 711,256 ​ $ 711,256 Depreciable property — held and used: ​ ​ ​ ​ Land improvements ​ ​ 97,807 ​ ​ 96,864 Buildings, improvements, and furniture, fixtures and equipment ​ 3,077,550 ​ 3,067,040 Real estate owned ​ 3,886,613 ​ 3,875,160 Accumulated depreciation ​ (1,831,814) ​ (1,796,568) Real estate owned, net ​ $ 2,054,799 ​ $ 2,078,592 ​ Acquisitions The Operating Partnership did not have any acquisitions of real estate during the three months ended March 31, 2020. Dispositions The Operating Partnership did not have any dispositions of real estate during the three months ended March 31, 2020. Other Activity Predevelopment, development, and redevelopment projects and related costs are capitalized and reported on the Consolidated Balance Sheets as Total real estate owned, net of accumulated depreciation In connection with the acquisition of certain properties, the Operating Partnership agreed to pay certain of the tax liabilities of certain contributors if the Operating Partnership sells one or more of the properties contributed in a taxable transaction prior to the expiration of specified periods of time following the acquisition. The Operating Partnership may, however, sell, without being required to pay any tax liabilities, any of such properties in a non-taxable transaction, including, but not limited to, a tax deferred Section 1031 exchange. Further, the Operating Partnership has agreed to maintain certain debt that may be guaranteed by certain contributors for specified periods of time following the acquisition. The Operating Partnership, however, has the ability to refinance or repay guaranteed debt or to substitute new debt if the debt and the guaranty continue to satisfy certain conditions.

UNCONSOLIDATED ENTITIES (UNITED

UNCONSOLIDATED ENTITIES (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Unconsolidated entities
UNCONSOLIDATED ENTITIES	5. JOINT VENTURES AND PARTNERSHIPS UDR has entered into joint ventures and partnerships with unrelated third parties to own, operate, acquire, renovate, develop, redevelop, dispose of, and manage real estate assets that are either consolidated and included in Real estate owned Investment in and advances to unconsolidated joint ventures, net Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest. UDR’s joint ventures and partnerships are funded with a combination of debt and equity. Our losses are typically limited to our investment and except as noted below, the Company does not guarantee any debt, capital payout or other obligations associated with our joint ventures and partnerships. The Company recognizes earnings or losses from our investments in unconsolidated joint ventures and partnerships consisting of our proportionate share of the net earnings or losses of the joint ventures and partnerships. In addition, we may earn fees for providing management services to the unconsolidated joint ventures and partnerships. The following table summarizes the Company’s investment in and advances to unconsolidated joint ventures and partnerships, net, which are accounted for under the equity method of accounting as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Number of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating ​ Apartment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ Communities ​ Homes ​ Investment at ​ UDR’s Ownership Interest ​ ​ Three Months Ended ​ Location of March 31, March 31, March 31, December 31, ​ March 31, ​ December 31, ​ March 31, Joint Venture Properties 2020 2020 2020 2019 ​ 2020 ​ 2019 ​ 2020 2019 Operating: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR/MetLife I ​ Los Angeles, CA ​ 1 ​ 150 ​ $ 28,570 ​ $ 28,812 ​ 50.0 % ​ 50.0 % ​ $ (454) ​ $ (576) UDR/MetLife II Various 7 1,250 ​ 150,652 ​ 150,893 ​ 50.0 % ​ 50.0 % ​ ​ (91) ​ ​ 434 Other UDR/MetLife Joint Ventures Various 5 1,437 ​ 94,109 ​ 98,441 ​ 50.6 % ​ 50.6 % ​ ​ (1,811) ​ ​ (1,777) West Coast Development Joint Ventures ​ Los Angeles, CA ​ 1 ​ 293 ​ ​ 34,943 ​ ​ 34,907 ​ 47.0 % ​ 47.0 % ​ ​ (77) ​ ​ (149) Sold Joint Ventures ​ ​ ​ ​ ​ ​ ​ ​ — ​ ​ — ​ — % ​ — % ​ ​ — ​ ​ (1,819) Investment in and advances to unconsolidated joint ventures, net, before preferred equity investments and other investments ​ $ 308,274 ​ $ 313,053 ​ ​ ​ ​ $ (2,433) ​ $ (3,887) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment at ​ Three Months Ended ​ Developer Capital Program ​ ​ Years To ​ UDR March 31, December 31, March 31, ​ and Other Investments (a) Location Rate Maturity ​ Commitment (b) 2020 2019 2020 2019 ​ Preferred equity investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ West Coast Development Joint Ventures (c) Hillsboro, OR 6.5 % N/A ​ $ — ​ $ — ​ $ 17,064 ​ $ (46) ​ $ (161) ​ 1532 Harrison ​ San Francisco, CA ​ 11.0 % 2.3 ​ ​ 24,645 ​ ​ 31,426 ​ ​ 30,585 ​ ​ 836 ​ ​ 748 ​ 1200 Broadway (d) ​ Nashville, TN ​ 8.0 % 2.5 ​ ​ 55,558 ​ ​ 65,254 ​ ​ 63,958 ​ ​ 1,281 ​ ​ 1,169 ​ Junction ​ Santa Monica, CA ​ 12.0 % 2.3 ​ ​ 8,800 ​ ​ 10,693 ​ ​ 10,379 ​ ​ 314 ​ ​ 275 ​ 1300 Fairmount (d) ​ Philadelphia, PA ​ Variable ​ 3.4 ​ ​ 51,393 ​ ​ 55,840 ​ ​ 51,215 ​ ​ 1,166 ​ ​ 275 ​ Essex ​ Orlando, FL ​ 12.5 % 3.4 ​ ​ 12,886 ​ ​ 15,270 ​ ​ 14,804 ​ ​ 466 ​ ​ 332 ​ Modera Lake Merritt (d) ​ Oakland, CA ​ 9.0 % 4.0 ​ ​ 27,250 ​ ​ 28,653 ​ ​ 22,653 ​ ​ 574 ​ ​ — ​ Thousand Oaks (e) ​ Thousand Oaks, CA ​ 9.0 % 4.9 ​ ​ 20,059 ​ ​ 5,994 ​ ​ — ​ ​ 24 ​ ​ — ​ Other investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The Portals ​ Washington, D.C. ​ 11.0 % 1.2 ​ ​ 38,559 ​ ​ 49,323 ​ ​ 48,181 ​ ​ 1,335 ​ ​ 1,173 ​ Other investment ventures ​ N/A ​ N/A ​ N/A ​ $ 34,500 ​ ​ 14,364 ​ ​ 13,598 ​ ​ (150) ​ ​ 125 ​ Total Developer Capital Program and Other Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 276,817 ​ ​ 272,437 ​ ​ 5,800 ​ ​ 3,936 ​ Total Joint Ventures and Developer Capital Program Investments, net (f) ​ ​ ​ ​ $ 585,091 ​ $ 585,490 ​ $ 3,367 $ 49 ​ (a) The Developer Capital Program is the program through which the Company makes investments, including preferred equity investments, mezzanine loans or other structured investments that may receive a fixed yield on the investment and may include provisions pursuant to which the Company participates in the increase in value of the property upon monetization of the applicable property and/or holds fixed price purchase options. (b) Represents UDR’s maximum funding commitment only and therefore excludes other activity such as income from investments. (c) In January 2020, the Company increased its ownership interest from 49% to 100% in the 276 apartment home operating community located in Hillsboro, Oregon, for a cash purchase price of approximately $21.6 million. As a result, the Company consolidated the operating community and it is no longer accounted for as a preferred equity investment in an unconsolidated joint venture (see Note 3, Real Estate Owned ). In connection with the purchase, the Company repaid the joint venture’s construction loan of approximately $35.6 million. (d) The Company’s preferred equity investment receives a variable percentage of the value created from the project upon a capital or liquidating event. (e) In February 2020, the Company entered into a joint venture agreement with an unaffiliated joint venture partner to develop and operate a 142 apartment home community in Thousand Oaks, CA. The Company’s preferred equity investment of up to $20.1 million earns a preferred return of 9.0% per annum and receives a variable percentage of the value created from the project upon a capital or liquidating event. The unaffiliated joint venture partner is the managing member of the joint venture and the developer of the community. The Company has concluded that it does not control the joint venture and, therefore, accounts for it under the equity method of accounting. (f) As of March 31, 2020, the Company’s negative investment in 13 th and Market Properties LLC of $3.3 million is included in Other UDR/MetLife Joint Ventures in the table above and recorded in Accounts payable, accrued expenses, and other liabilities on the Consolidated Balance Sheet. As of March 31, 2020 and December 31, 2019, the Company had deferred fees of $9.0 million and $9.0 million, respectively, which will be recognized through earnings over the weighted average life of the related properties, upon the disposition of the properties to a third party, or upon completion of certain development obligations. The Company recognized management fees of $1.4 million and $ 2.8 million for the three months ended March 31, 2020 and 2019, respectively, for management of the communities held by the joint ventures and partnerships. The management fees are included in Joint venture management and other fees on the Consolidated Statements of Operations. The Company may, in the future, make additional capital contributions to certain of our joint ventures and partnerships should additional capital contributions be necessary to fund acquisitions or operations. We evaluate our investments in unconsolidated joint ventures and partnerships when events or changes in circumstances indicate that there may be an other-than-temporary decline in value. We consider various factors to determine if a decrease in the value of the investment is other-than-temporary. The Company did not recognize any other-than-temporary impairments in the value of its investments in unconsolidated joint ventures or partnerships during the three months ended March 31, 2020 and 2019. Combined summary balance sheets relating to the unconsolidated joint ventures’ and partnerships’ (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,868,502 $ 1,901,081 Cash and cash equivalents ​ 32,486 ​ 29,823 Other assets ​ ​ 180,893 ​ 172,941 Total assets $ 2,081,881 $ 2,103,845 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,136,306 ​ $ 1,148,048 Accounts payable and accrued liabilities ​ ​ 50,262 ​ ​ 55,114 Total liabilities ​ 1,186,568 ​ 1,203,162 Total equity $ 895,313 $ 900,683 ​ Combined summary financial information relating to the unconsolidated joint ventures’ and partnerships’ operations (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenues $ 41,314 $ 81,532 Property operating expenses ​ 15,297 ​ 30,312 Real estate depreciation and amortization ​ 16,243 ​ 29,580 Operating income/(loss) ​ 9,774 ​ ​ 21,640 Interest expense ​ (10,347) ​ (21,924) Net unrealized gain/(loss) on held investments ​ ​ — ​ ​ 1,522 Other income/(loss) ​ ​ (8) ​ ​ 103 Net income/(loss) $ (581) $ 1,341 (1)
United Dominion Realty L.P.
Unconsolidated entities
UNCONSOLIDATED ENTITIES	4. UNCONSOLIDATED ENTITIES The DownREIT Partnership is accounted for by the Operating Partnership under the equity method of accounting and is included in Investment in unconsolidated entities The DownREIT Partnership is a VIE as the limited partners lack substantive kick-out rights and substantive participating rights. The Operating Partnership is not the primary beneficiary of the DownREIT Partnership as it lacks the power to direct the activities that most significantly impact its economic performance and will continue to account for its interest as an equity method investment. See Note 2, Significant Accounting Policies As of March 31, 2020, the DownREIT Partnership owned 12 communities with 5,657 apartment homes. The Operating Partnership’s investment in the DownREIT Partnership was $69.6 million and $76.2 million as of March 31, 2020 and December 31, 2019, respectively. Combined summary balance sheets relating to all of the DownREIT Partnership (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,088,125 $ 1,106,703 Cash and cash equivalents ​ 20 ​ 20 Note receivable from the General Partner ​ 220,622 ​ 222,853 Other assets ​ 5,312 ​ 4,829 Total assets $ 1,314,079 $ 1,334,405 ​ ​ ​ ​ ​ ​ ​ Secured debt, net ​ $ 426,724 ​ $ 427,592 Other liabilities ​ 23,628 ​ 28,087 Total liabilities ​ 450,352 ​ 455,679 Total capital ​ $ 863,727 ​ $ 878,726 ​ Combined summary financial information relating to all of the DownREIT Partnership (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenue ​ $ 32,678 $ 31,606 Property operating expenses ​ (13,309) ​ (13,096) Real estate depreciation and amortization ​ (20,986) ​ (20,294) Operating income/(loss) ​ (1,617) ​ (1,784) Interest expense ​ (3,618) ​ (3,888) Other income/(loss) ​ 1,889 ​ 1,988 Net income/(loss) ​ $ (3,346) $ (3,684) ​

LEASES (UNITED DOMINION REALTY,

LEASES (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
LEASES	6. LEASES Lessee - Ground Leases UDR owns six communities that are subject to ground leases, under which UDR is the lessee, expiring between 2043 and 2103, inclusive of extension options we are reasonably certain will be exercised. All of these leases are classified as operating leases through the lease term expiration based on our election of the practical expedient provided by the leasing standard. Rental expense for lease payments related to operating leases is recognized on a straight-line basis over the remaining lease term. We currently do not hold any finance leases. The Company also elected the short-term lease exception provided by the leasing standard and therefore only recognizes right-of-use assets and lease liabilities for leases with a term greater than one year. No leases qualified for the short-term lease exception during the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Operating lease right-of-use assets Operating lease liabilities Operating lease right-of-use assets Operating lease liabilities As the discount rate implicit in the leases was not readily determinable, we determined the discount rate for these leases utilizing the Company’s incremental borrowing rate at a portfolio level, adjusted for the remaining lease term, and the form of underlying collateral. The weighted average remaining lease term for these leases was 44.5 years at March 31, 2020 and the weighted average discount rate was 5.0% at March 31, 2020. Future minimum lease payments and total operating lease liabilities from our ground leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2020 ​ $ 9,330 2021 ​ ​ 12,442 2022 ​ ​ 12,442 2023 ​ ​ 12,442 2024 ​ ​ 12,442 Thereafter ​ ​ 455,221 Total future minimum lease payments (undiscounted) ​ ​ 514,319 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) Total operating lease liabilities (discounted) ​ $ 197,829 ​ For purposes of recognizing our ground lease contracts, the Company uses the minimum lease payments, if stated in the agreement. For ground lease agreements where there is a rent reset provision based on a change in an index or a rate (i.e., changes in fair market rental rates or changes in the consumer price index) but that does not include a specified minimum lease payment, the Company uses the current rent over the remainder of the lease term. If there is a contingency upon which some or all of the variable lease payments that will be paid over the remainder of the lease term are based, which is resolved such that those payments now meet the definition of lease payments, the Company will remeasure the right-of-use asset and lease liability on the reset date. The components of operating lease expenses were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2020 ​ 2019 Lease expense: ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,170 ​ $ 2,159 Variable lease expense (a) ​ ​ 43 ​ ​ 139 Total operating lease expense (b)(c) ​ $ 3,213 ​ $ 2,298 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.8 million and $0.7 million, respectively, and for the three months ended March 31, 2019 Operating lease right-of-use assets and Operating lease liabilities amortized by $0.2 million and $0.1 million, respectively. The Company recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization. ​ Lessor - Apartment Home, Retail and Commercial Space Leases ​ UDR’s communities and retail and commercial space are leased to tenants under operating leases. As of March 31, 2020, our apartment home leases generally have initial terms of 12 months or less and represent approximately 98.4% of our total lease revenue. As of March 31, 2020, our retail and commercial space leases generally have initial terms of between 5 and 15 years and represent approximately 1.6% of our total lease revenue. Our apartment home leases are generally renewable at the end of the lease term, subject to potential increases in rental rates, and our retail and commercial space leases generally have renewal options, subject to associated increases in rental rates due to market based or fixed price renewal options and certain other conditions. (See Note 14, Reportable Segments ​ Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 16,849 2021 ​ ​ 22,487 2022 ​ ​ 20,781 2023 ​ ​ 19,317 2024 ​ ​ 17,594 Thereafter ​ ​ 81,662 Total future minimum lease payments (a) ​ $ 178,690 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months or less. Certain of our leases with retail and commercial tenants provide for the payment by the lessee of additional variable rent based on a percentage of the tenant’s revenue. The amounts shown in the table above do not include these variable percentage rents. The Company recorded variable percentage rents of $0.1 million and less than $0.2 million during the three months ended March 31, 2020 and 2019, respectively.
United Dominion Realty L.P.
Entity information
LEASES	5. LEASES Lessee - Ground and Equipment Leases The Operating Partnership owns six communities that are subject to ground leases, under which the Operating Partnership is the lessee, expiring between 2043 and 2103, inclusive of extension options we are reasonably certain will be exercised. All of these leases are classified as operating leases through the lease term expiration based on our election of the practical expedient provided by the leasing standard. Rental expense for lease payments related to operating leases is recognized on a straight-line basis over the remaining lease term. In addition, the Operating Partnership leases equipment at The Operating Partnership also elected the short-term lease exception provided by the leasing standard and therefore only recognizes right-of-use assets and lease liabilities for leases with a term greater than one year. No leases qualified for the short-term lease exception during the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Operating lease right-of-use assets Operating lease liabilities Operating lease right-of-use assets Operating lease liabilities As the discount rate implicit in the leases was not readily determinable, we determined the discount rate for these leases utilizing the Operating Partnership’s incremental borrowing rate at a portfolio level, adjusted for the remaining lease term, and the form of underlying collateral. The weighted average remaining lease term for these leases was 44.5 years at March 31, 2020 and the weighted average discount rate was 5.0% at March 31, 2020. Future minimum lease payments and total operating lease liabilities from our ground and equipment leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ground Leases ​ Equipment Leases ​ Total 2020 ​ $ 9,330 ​ $ 108 ​ $ 9,438 2021 ​ ​ 12,442 ​ ​ 147 ​ ​ 12,589 2022 ​ ​ 12,442 ​ ​ 150 ​ ​ 12,592 2023 ​ ​ 12,442 ​ ​ 153 ​ ​ 12,595 2024 ​ ​ 12,442 ​ ​ 156 ​ ​ 12,598 Thereafter ​ ​ 455,221 ​ ​ 795 ​ ​ 456,016 Total future minimum lease payments (undiscounted) ​ ​ 514,319 ​ ​ 1,509 ​ ​ 515,828 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) ​ ​ (189) ​ ​ (316,679) Total operating lease liabilities (discounted) ​ $ 197,829 ​ $ 1,320 ​ $ 199,149 ​ For purposes of recognizing our ground lease contracts, the Operating Partnership uses the minimum lease payments, if stated in the agreement. For ground lease agreements where there is a rent reset provision based on a change in an index or a rate (i.e., changes in fair market rental rates or changes in the consumer price index) but that does not include a specified minimum lease payment, the Operating Partnership uses the current rent over the remainder of the lease term. If there is a contingency, upon which some or all of the variable lease payments that will be paid over the remainder of the lease term are based, which is resolved such that those payments now meet the definition of lease payments, the Operating Partnership will remeasure the right-of-use asset and lease liability on the reset date. The components of operating lease expenses from our ground and equipment leases were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Ground lease expense: ​ ​ ​ ​ ​ ​ Contractual ground lease rent expense ​ $ 3,170 ​ $ 2,140 Variable ground lease expense (a) ​ ​ 43 ​ ​ 139 Total ground lease expense (b) ​ ​ 3,213 ​ ​ 2,279 Contractual equipment lease expense (b) ​ ​ 36 ​ ​ - Total operating lease expense (c) ​ $ 3,249 ​ $ 2,279 (a) Variable ground lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Ground lease and equipment lease expense are reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.9 million and $0.9 million, respectively. The Operating Partnership recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization. ​ Lessor - Apartment Home and Retail and Commercial Leases ​ The Operating Partnership’s communities and retail and commercial space are leased to tenants under operating leases. As of March 31, 2020, our apartment home leases generally have initial terms of 12 months or less and represent 98.4% of our total lease revenue. As of March 31, 2020, our retail and commercial space leases generally have initial terms between 5 and 15 years and represent approximately 1.6% of our total lease revenue. Our apartment home leases are generally renewable at the end of the lease term, subject to potential increases in rental rates, and our retail and commercial space leases generally have renewal options, subject to associated increases in rental rates and certain other conditions. (See Note 12, Reportable Segments ​ Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 5,678 2021 ​ ​ 7,311 2022 ​ ​ 6,688 2023 ​ ​ 6,361 2024 ​ ​ 5,693 Thereafter ​ ​ 14,807 Total future minimum lease payments (a) ​ $ 46,538 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months of less. Certain of our leases with retail and commercial tenants provide for the payment by the lessee of additional variable rent based on a percentage of the tenant’s revenue. The amounts shown in the table above do not include these variable percentage rents. The Operating Partnership recorded variable percentage rents of less than $0.1 million and less than $0.1 million during the three months ended March 31, 2020 and 2019, respectively.

DEBT, NET (UNITED DOMINION REAL

DEBT, NET (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
DEBT, NET	7. SECURED AND UNSECURED DEBT, NET The following is a summary of our secured and unsecured debt at March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ March 31, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2020 2019 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 883,249 ​ $ 884,869 3.61 % 5.9 15 Credit facilities (b) ​ 203,429 ​ 204,590 4.90 % 2.8 4 Deferred financing costs and other non-cash adjustments ​ 30,585 ​ 33,046 Total fixed rate secured debt, net ​ 1,117,263 ​ 1,122,505 3.85 % 5.3 19 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, net ​ 1,144,201 ​ 1,149,441 3.80 % 5.5 20 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2023 (d) (m) ​ 50,000 ​ — 1.75 % 2.8 Borrowings outstanding under unsecured commercial paper program due April 2020 (e) (m) (n) ​ ​ 215,000 ​ ​ 300,000 ​ 1.58 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2021 ​ 24,797 ​ 16,583 1.82 % 0.8 Term Loan due September 2023 (d) (m) ​ 35,000 ​ 35,000 2.48 % 3.5 Fixed Rate Debt ​ ​ 1.93% Term Loan due September 2023 (d) (m) ​ ​ 315,000 ​ 315,000 1.93 % 3.5 ​ ​ 3.75% Medium-Term Notes due July 2024 (net of discounts of $443 and $470, respectively) (g) (m) ​ 299,557 ​ 299,530 3.75 % 4.3 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 4.5 4.00% Medium-Term Notes due October 2025 (net of discounts of $379 and $396, respectively) (h) (m) ​ 299,621 ​ 299,604 4.00 % 5.5 2.95% Medium-Term Notes due September 2026 (m) ​ 300,000 ​ 300,000 2.95 % 6.4 3.50% Medium-Term Notes due July 2027 (net of discounts of $511 and $529, respectively) (m) ​ ​ 299,489 ​ ​ 299,471 ​ 3.50 % 7.3 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $924 and $954, respectively) (m) ​ ​ 299,076 ​ ​ 299,046 ​ 3.50 % 7.8 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $5 and $5, respectively) (i) (m) ​ ​ 299,995 ​ ​ 299,995 ​ 4.40 % 8.8 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $13,442 and $2,281, respectively) (j) (m) ​ ​ 613,442 ​ ​ 402,281 ​ 3.20 % 9.8 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of discounts of $1,099 and $1,123, respectively) (k) (m) ​ ​ 398,901 ​ ​ 398,877 ​ 3.00 % 11.4 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $1,287 and $1,309, respectively) (l) (m) ​ ​ 298,713 ​ ​ 298,691 ​ 3.10 % 14.6 ​ ​ Other ​ 12 ​ 13 Deferred financing costs ​ (23,310) ​ (21,652) Total Unsecured Debt, net ​ 3,740,937 ​ 3,558,083 3.29 % 7.5 Total Debt, net ​ $ 4,885,138 ​ $ 4,707,524 3.28 % 7.1 ​ For purposes of classification of the above table, variable rate debt with a derivative financial instrument designated as a cash flow hedge is deemed as fixed rate debt due to the Company having effectively established a fixed interest rate for the underlying debt instrument. Our secured debt instruments generally feature either monthly interest and principal or monthly interest-only payments with balloon payments due at maturity. As of March 31, 2020, secured debt encumbered $2.1 billion or 16.6% of UDR’s total real estate owned based upon gross book value ($10.7 billion or 83.4% of UDR’s real estate owned based on gross book value is unencumbered). (a) The Company will from time to time acquire properties subject to fixed rate debt instruments. In those situations, the Company records the debt at its estimated fair value and amortizes any difference between the fair value and par value to interest expense over the life of the underlying debt instrument. (b) During the three months ended March 31, 2020 and 2019, the Company had $2.6 million and $0.6 million, respectively, of amortization of the fair market adjustment of debt assumed in the acquisition of properties inclusive of its fixed rate mortgage notes payable and credit facilities, which was included in Interest expense ​ (c) (d) six-month extension options, subject to certain conditions. The Term Loan has a scheduled maturity date of September 30, 2023. Based on the Company’s current credit rating, the Revolving Credit Facility has an interest rate equal to LIBOR plus a margin of 82.5 basis points and a facility fee of 15 basis points, and the Term Loan has an interest rate equal to LIBOR plus a margin of 90 basis points. Depending on the Company’s credit rating, the margin under the Revolving Credit Facility ranges from 75 to 145 basis points, the facility fee ranges from 10 to 30 basis points, and the margin under the Term Loan ranges from 80 to 165 basis points. The Credit Agreement contains customary representations and warranties and financial and other affirmative and negative covenants. The Credit Agreement also includes customary events of default, in certain cases subject to customary periods to cure. The occurrence of an event of default, following the applicable cure period, would permit the lenders to, among other things, declare the unpaid principal, accrued and unpaid interest and all other amounts payable under the Credit Agreement to be immediately due and payable. The following is a summary of short-term bank borrowings under the Revolving Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 2019 ​ Total revolving credit facility ​ $ 1,100,000 ​ $ 1,100,000 ​ Borrowings outstanding at end of period (1) ​ 50,000 ​ — ​ Weighted average daily borrowings during the period ended ​ 11,538 ​ 55 ​ Maximum daily borrowings during the period ended ​ 50,000 ​ 20,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.6 % Interest rate at end of the period ​ 1.8 % — % (1) Excludes $2.5 million and $2.9 million of letters of credit at March 31, 2020 and December 31, 2019, respectively . (e) The following is a summary of short-term bank borrowings under the unsecured commercial paper program at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total unsecured commercial paper program $ 500,000 ​ $ 500,000 ​ Borrowings outstanding at end of period ​ 215,000 ​ 300,000 ​ Weighted average daily borrowings during the period ended ​ 346,978 ​ 173,353 ​ Maximum daily borrowings during the period ended ​ 500,000 ​ 435,000 ​ Weighted average interest rate during the period ended ​ 1.8 % 2.5 % Interest rate at end of the period ​ 1.6 % 2.0 % ​ (f) 82.5 basis points. Depending on the Company’s credit rating, the margin ranges from 75 to 145 basis points. The following is a summary of short-term bank borrowings under the Working Capital Credit Facility at March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Total working capital credit facility ​ $ 75,000 ​ $ 75,000 ​ Borrowings outstanding at end of period ​ 24,797 ​ 16,583 ​ Weighted average daily borrowings during the period ended ​ 25,212 ​ 23,487 ​ Maximum daily borrowings during the period ended ​ 46,419 ​ 66,170 ​ Weighted average interest rate during the period ended ​ 2.2 % 3.1 % Interest rate at end of the period ​ 1.8 % 2.6 % ​ (g) (h) (i) (j) In February 2020, the Company issued $200.0 million of 3.20% senior unsecured medium-term notes due 2030. Interest is payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2020. The notes were priced at 105.660% of the principal amount at issuance. This was a further issuance of the 2030 notes, and forms a single series with, the $300.0 million aggregate principal amount of the Company’s 3.20% notes due 2030 that were issued in July 2019 and the $100.0 million aggregate principal amount of the Company’s 3.20% notes due 2030 that were issued in October 2019. As of the completion of the offering, the aggregate principal amount of outstanding 2030 notes was $600.0 million. (k) (l) . (m) The aggregate maturities, including amortizing principal payments on secured and unsecured debt, of total debt for the next ten calendar years subsequent to March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2020 ​ $ 112,592 ​ $ — ​ $ 112,592 ​ $ 215,000 (a) $ 327,592 2021 ​ ​ 8,763 ​ ​ — ​ ​ 8,763 ​ ​ 24,797 ​ ​ 33,560 2022 ​ 9,159 ​ — ​ 9,159 ​ — ​ 9,159 2023 ​ 295,965 ​ — ​ 295,965 ​ 400,000 ​ 695,965 2024 ​ 95,280 ​ — ​ 95,280 ​ 315,644 ​ 410,924 2025 ​ 173,189 ​ — ​ 173,189 ​ 300,000 ​ 473,189 2026 ​ 51,070 ​ — ​ 51,070 ​ 300,000 ​ 351,070 2027 ​ 1,111 ​ — ​ 1,111 ​ 300,000 ​ 301,111 2028 ​ 122,465 ​ — ​ 122,465 ​ 300,000 ​ 422,465 2029 ​ 144,584 ​ — ​ 144,584 ​ 300,000 ​ 444,584 Thereafter ​ 72,500 ​ 27,000 ​ 99,500 ​ 1,300,000 ​ 1,399,500 Subtotal ​ 1,086,678 ​ 27,000 ​ 1,113,678 ​ 3,755,441 ​ 4,869,119 Non-cash (b) ​ 30,585 ​ (62) ​ 30,523 ​ (14,504) ​ 16,019 Total ​ $ 1,117,263 ​ $ 26,938 ​ $ 1,144,201 ​ $ 3,740,937 ​ $ 4,885,138 (a) All unsecured debt due in the remainder of 2020 is related to the Company’s commercial paper program. (b) Includes the unamortized balance of fair market value adjustments, premiums/discounts and deferred financing costs . The Company amortized $1.0 million and $1.0 million, respectively, during the three months ended March 31, 2020 and 2019, of deferred financing costs into Interest expense. We were in compliance with the covenants of our debt instruments at March 31, 2020. (n)
United Dominion Realty L.P.
Entity information
DEBT, NET	6. DEBT, NET Our secured debt instruments generally feature either monthly interest and principal or monthly interest-only payments with balloon payments due at maturity. For purposes of classification in the following table, variable rate debt with a derivative financial instrument designated as a cash flow hedge is deemed as fixed rate debt due to the Operating Partnership having effectively established the fixed interest rate for the underlying debt instrument. Secured debt consists of the following as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ March 31, ​ December 31, ​ Average ​ Years to ​ Communities ​ ​ 2020 ​ 2019 ​ Interest Rate ​ Maturity ​ Encumbered Fixed Rate Debt ​ ​ Mortgage note payable ​ $ 72,500 ​ $ 72,500 3.10 % 9.8 1 Deferred financing costs ​ (356) ​ (365) Total fixed rate secured debt, net ​ 72,144 ​ 72,135 3.10 % 9.8 1 Variable Rate Debt ​ ​ Tax-exempt secured note payable ​ $ 27,000 ​ $ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, Net ​ $ 99,082 ​ $ 99,071 2.83 % 10.4 2 ​ The Operating Partnership may from time to time acquire properties subject to fixed rate debt instruments. In those situations, management will record the secured debt at its estimated fair value and amortize any difference between the fair value and par to interest expense over the life of the underlying debt instrument. The Operating Partnership did not have any unamortized fair value adjustments associated with the fixed rate debt instruments on the Operating Partnership’s properties. Fixed Rate Debt Mortgage note payable Variable Rate Debt Tax-exempt secured note payable. Guarantor on Unsecured Debt The Operating Partnership is the guarantor on the General Partner’s unsecured revolving credit facility with an aggregate borrowing capacity of $1.1 billion, an unsecured commercial paper program with an aggregate borrowing capacity of $500 million, a $350 million term loan due September 2023, $300 million of medium-term notes due July 2024, $300 million of medium-term notes due October 2025, $300 million of medium-term notes due September 2026, $300 million of medium-term notes due July 2027, $300 million of medium-term notes due January 2028, $300 million of medium-term notes due January 2029, $600 million of medium-term notes due January 2030, $400 million of medium-term notes due August 2031, and $300 million of medium-term notes due November 2034. As of March 31, 2020 and December 31, 2019, the General Partner had $50.0 million and zero, respectively, outstanding balance under the unsecured revolving credit facility and had $215.0 million and $300.0 million, respectively, outstanding under its unsecured commercial paper program. In April 2020, the entire $215.0 million of outstanding unsecured commercial paper as of March 31, 2020 was repaid at maturity with draws on the General Partner’s Revolving Credit Facility and Working Capital Credit Facility.

RELATED PARTY TRANSACTIONS (UNI

RELATED PARTY TRANSACTIONS (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
United Dominion Realty L.P.
Entity information
RELATED PARTY TRANSACTIONS	7. RELATED PARTY TRANSACTIONS Shared Services The Operating Partnership self-manages its own properties and is party to an Inter-Company Employee and Cost Sharing Agreement with the General Partner. This agreement provides for reimbursements to the General Partner for the Operating Partnership’s allocable share of costs incurred by the General Partner for (a) general and administrative costs, and (b) shared services of corporate level property management employees and related support functions and costs. Allocation of General and Administrative Expenses The General Partner shares various general and administrative costs, employees and other overhead costs with the Operating Partnership including legal assistance, acquisitions analysis, marketing, human resources, IT, accounting, rent, supplies and advertising, and allocates these costs to the Operating Partnership first on the basis of direct usage when identifiable, with the remainder allocated based on the reasonably anticipated benefits to the parties. The general and administrative expenses allocated to the Operating Partnership by UDR were $3.6 million and $3.6 million during both of the three months ended March 31, 2020 and 2019, respectively, and are included in General and administrative During the three months ended March 31, 2020 and 2019, the Operating Partnership reimbursed the General Partner $4.9 million and $4.0 million, respectively, for shared services related to corporate level property management costs incurred by the General Partner. These shared cost reimbursements are initially recorded within the line item General and administrative Property management Notes Payable to the General Partner The following table summarizes the Operating Partnership’s Notes payable due to the General Partner as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, ​ March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due August 2021 5.34 % ​ $ 5,500 ​ $ 5,500 Note due December 2023 5.18 % ​ 83,196 ​ 83,196 Note due April 2026 4.12 % ​ 184,638 ​ 184,638 Note due November 2028 ​ 4.69 % ​ ​ 133,205 ​ ​ 133,205 Note due December 2028 (a) ​ 3.28 % ​ ​ 229,199 ​ ​ 230,694 Total notes payable due to the General Partner ​ ​ $ 635,738 ​ $ 637,233 (a) There is no limit on the total commitments under this unsecured revolving note. Interest is incurred on the unpaid principal balance at a variable interest rate equivalent to the General Partner’s weighted average interest rate on borrowings, or 3.28% as of March 31, 2020. The note matures on December 1, 2028. To the extent there is an outstanding principal balance on the revolving note payable, the General Partner, at its discretion, can demand payment at any time prior to the stated maturity date of the note. Certain limited partners of the Operating Partnership have provided guarantees or reimbursement agreements related to these notes payable. The guarantees were provided by the limited partners in conjunction with their contribution of properties to the Operating Partnership. The Operating Partnership recognized interest expense on the notes payable of $6.7 million and $7.2 million during the three months ended March 31, 2020 and 2019, respectively.

FAIR VALUE OF DERIVATIVES AND_4

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS	10. FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS Fair value is based on the price that would be received to sell an asset or the exit price that would be paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level valuation hierarchy prioritizes observable and unobservable inputs used to measure fair value. The fair value hierarchy consists of three broad levels, which are described below: ● Level 1 — Quoted prices in active markets for identical assets or liabilities that the entity has the ability to access. ● Level 2 — Observable inputs other than prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated with observable market data. ● Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The estimated fair values of the Company’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 Total assets ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 3,075 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 903,243 ​ ​ 908,088 ​ ​ — ​ ​ — ​ ​ 908,088 Credit facilities ​ 216,181 ​ 213,026 ​ — ​ — ​ 213,026 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ Revolving credit facility ​ ​ 50,000 ​ ​ 50,000 ​ ​ — ​ ​ — ​ ​ 50,000 Working capital credit facility ​ ​ 24,797 ​ ​ 24,797 ​ ​ — ​ ​ — ​ ​ 24,797 Commercial paper program ​ ​ 215,000 ​ ​ 215,000 ​ ​ — ​ ​ — ​ ​ 215,000 Unsecured notes ​ ​ 3,474,450 ​ ​ 3,466,082 ​ ​ — ​ ​ — ​ ​ 3,466,082 Total liabilities ​ $ 4,913,746 ​ $ 4,907,068 ​ $ — ​ $ 3,075 ​ $ 4,903,993 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 819,133 ​ $ 819,133 ​ $ — ​ $ 819,133 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 153,650 ​ $ 160,197 ​ $ — ​ $ — ​ $ 160,197 Derivatives - Interest rate contracts (c) ​ 6 ​ 6 ​ — ​ 6 ​ — Total assets ​ $ 153,656 ​ $ 160,203 ​ $ — ​ $ 6 ​ $ 160,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 142 ​ $ 142 ​ $ — ​ $ 142 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 906,228 ​ ​ 898,329 ​ ​ — ​ ​ — ​ ​ 898,329 Credit facilities ​ 218,490 ​ 213,661 ​ — ​ — ​ 213,661 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 16,583 ​ ​ 16,583 ​ ​ — ​ ​ — ​ ​ 16,583 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 3,263,152 ​ ​ 3,397,622 ​ ​ — ​ ​ — ​ ​ 3,397,622 Total liabilities ​ $ 4,731,595 ​ $ 4,853,337 ​ $ — ​ $ 142 ​ $ 4,853,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 1,018,665 ​ $ 1,018,665 ​ $ — ​ $ 1,018,665 ​ $ — (a) Balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) See Note 11, Derivatives and Hedging Activity . (d) See Note 7, Secured and Unsecured Debt, Net . (e) See Note 9, Noncontrolling Interests. There were no transfers into or out of any of the levels of the fair value hierarchy during the three months ended March 31, 2020. Financial Instruments Carried at Fair Value The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The fair values of interest rate options are determined using the market standard methodology of discounting the future expected cash receipts that would occur if variable interest rates rise above the strike rate of the caps. The variable interest rates used in the calculation of projected receipts on the cap are based on an expectation of future interest rates derived from observable market interest rate curves and volatilities. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2020 and December 31, 2019, the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. In conjunction with the FASB’s fair value measurement guidance, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership have a redemption feature and are marked to their redemption value. The redemption value is based on the fair value of the Company’s common stock at the redemption date, and therefore, is calculated based on the fair value of the Company’s common stock at the balance sheet date. Since the valuation is based on observable inputs such as quoted prices for similar instruments in active markets, redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership are classified as Level 2. Financial Instruments Not Carried at Fair Value At March 31, 2020 and December 31, 2019, the fair values of cash and cash equivalents, restricted cash, accounts receivable, prepaids, real estate taxes payable, accrued interest payable, security deposits and prepaid rent, distributions payable and accounts payable approximated their carrying values because of the short term nature of these instruments. The estimated fair values of other financial instruments, which includes notes receivable and debt instruments, are classified in Level 3 of the fair value hierarchy due to the significant unobservable inputs that are utilized in their respective valuations. We record impairment losses on long-lived assets used in operations when events and circumstances indicate that the assets might be impaired and the undiscounted cash flows estimated to be generated by the future operation and disposition of those assets are less than the net book value of those assets. Our cash flow estimates are based upon historical results adjusted to reflect our best estimate of future market and operating conditions and our estimated holding periods. The net book value of impaired assets is reduced to fair value. Our estimates of fair value represent our best estimate based upon Level 3 inputs such as industry trends and reference to market rates and transactions. We consider various factors to determine if a decrease in the value of our Investment in and advances to unconsolidated joint ventures, net After determining that an other-than-temporary decrease in the value of an equity method investment has occurred, we estimate the fair value of our investment by estimating the proceeds we would receive upon a hypothetical liquidation of the investment at the date of measurement. Inputs reflect management’s best estimate of what market participants would use in pricing the investment giving consideration to the terms of the joint venture agreement and the estimated discounted future cash flows to be generated from the underlying joint venture assets. The inputs and assumptions utilized to estimate the future cash flows of the underlying assets are based upon the Company’s evaluation of the economy, market trends, operating results, and other factors, including judgments regarding costs to complete any construction activities, lease up and occupancy rates, rental rates, inflation rates, capitalization rates utilized to estimate the projected cash flows at the disposition, and discount rates.
United Dominion Realty L.P.
Entity information
FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS	8. FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS Fair value is based on the price that would be received to sell an asset or the exit price that would be paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level valuation hierarchy prioritizes observable and unobservable inputs used to measure fair value. The fair value hierarchy consists of three broad levels, which are described below: ● Level 1 — Quoted prices in active markets for identical assets or liabilities that the entity has the ability to access. ● Level 2 — Observable inputs other than prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated with observable market data. ● Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The estimated fair values of the Operating Partnership’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019 are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ Total ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ Secured debt instrument - fixed rate: (b) ​ ​ ​ ​ ​ Mortgage note payable ​ $ 72,500 ​ $ 73,663 ​ $ — ​ $ — ​ $ 73,663 Secured debt instrument - variable rate: (b) ​ ​ ​ ​ ​ ​ Tax-exempt secured note payable ​ ​ 27,000 ​ ​ 27,000 ​ ​ — ​ ​ — ​ ​ 27,000 Total liabilities ​ $ 99,500 ​ $ 100,663 ​ $ — ​ $ — ​ $ 100,663 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Total ​ ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ ​ Markets ​ ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ for Identical ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ Assets ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (b) ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 72,500 ​ $ 71,976 ​ $ — ​ $ — ​ $ 71,976 Secured debt instrument - variable rate: (b) ​ ​ ​ ​ ​ ​ Tax-exempt secured note payable ​ $ 27,000 ​ $ 27,000 ​ $ — ​ $ — ​ $ 27,000 Total liabilities ​ $ 99,500 ​ $ 98,976 ​ $ — ​ $ — ​ $ 98,976 (a) Balances exclude deferred financing costs. (b) See Note 6, Debt, Net. ​ There were no transfers into or out of each of the levels of the fair value hierarchy during the three months ended March 31, 2020. ​ Financial Instruments Carried at Fair Value The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The fair values of interest rate options are determined using the market standard methodology of discounting the future expected cash receipts that would occur if variable interest rates rise above the strike rate of the caps. The variable interest rates used in the calculation of projected receipts on the cap are based on an expectation of future interest rates derived from observable market interest rate curves and volatilities. The General Partner, on behalf of the Operating Partnership, incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Operating Partnership has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although the General Partner, on behalf of the Operating Partnership, has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2020 and December 31, 2019, the Operating Partnership has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Operating Partnership has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. In conjunction with the FASB’s fair value measurement guidance, the Operating Partnership made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Financial Instruments Not Carried at Fair Value As of March 31, 2020, the fair values of cash and cash equivalents, restricted cash, accounts receivable, prepaids, real estate taxes payable, accrued interest payable, security deposits and prepaid rent, distributions payable and accounts payable approximated their carrying values because of the short term nature of these instruments. The estimated fair values of other financial instruments, which includes debt instruments, are classified in Level 3 of the fair value hierarchy due to the significant unobservable inputs that are utilized in their respective valuations. The Operating Partnership records impairment losses on long-lived assets used in operations when events and circumstances indicate that the assets might be impaired and the undiscounted cash flows estimated to be generated by the future operation and disposition of those assets are less than the net book value of those assets. Cash flow estimates are based upon historical results adjusted to reflect management’s best estimate of future market and operating conditions and our estimated holding periods. The net book value of impaired assets is reduced to fair value. The General Partner’s estimates of fair value represent management’s estimates based upon Level 3 inputs such as industry trends and reference to market rates and transactions. The Operating Partnership did not incur any impairments on long-lived assets or any other-than-temporary impairments in the value of its investments in unconsolidated entities during the three months ended March 31, 2020 and 2019.

DERIVATIVES AND HEDGING ACTIV_8

DERIVATIVES AND HEDGING ACTIVITY (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
DERIVATIVES AND HEDGING ACTIVITY	11. DERIVATIVES AND HEDGING ACTIVITY Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its debt funding and through the use of derivative financial instruments. Specifically, the Company may enter into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s investments and borrowings. Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company primarily uses interest rate swaps and caps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for an up-front premium. The changes in the fair value of derivatives designated and that qualify as cash flow hedges are recorded in Accumulated other comprehensive income/(loss), net Amounts reported in Accumulated other comprehensive income/(loss), net Interest expense As of March 31, 2020, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ Product ​ Instruments ​ Notional Interest rate swaps ​ 1 ​ $ 315,000 ​ Derivatives not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of GAAP. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings and resulted in no gain or loss for both the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Company had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps ​ 1 ​ $ 19,880 ​ Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheet The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ March 31, ​ December 31, ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ — ​ $ 6 ​ $ 3,075 ​ $ 142 ​ Tabular Disclosure of the Effect of Derivative Instruments on the Consolidated Statements of Operations The tables below present the effect of the Company’s derivative financial instruments on the Consolidated Statements of Operations for the three months ended March 31, 2020 and 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain/(Loss) Recognized in ​ ​ ​ ​ Gain/(Loss) Reclassified ​ Interest expense ​ ​ Unrealized holding gain/(loss) ​ from Accumulated OCI into ​ (Amount Excluded from ​ ​ Recognized in OCI ​ Interest expense ​ Effectiveness Testing) Derivatives in Cash Flow Hedging Relationships 2020 2019 2020 2019 2020 2019 Three Months Ended March 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ (2,917) ​ $ (2,210) ​ $ (357) ​ $ 945 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Total amount of Interest expense ​ $ 39,317 ​ $ 33,542 ​ The Company did not recognize any gain/(loss) in Interest income and other income/(expense), net Credit-risk-related Contingent Features The Company has agreements with its derivative counterparties that contain a provision where the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company’s default on the indebtedness. The Company has certain agreements with some of its derivative counterparties that contain a provision where, in the event of default by the Company or the counterparty, the right of setoff may be exercised. Any amount payable to one party by the other party may be reduced by its setoff against any amounts payable by the other party. Events that give rise to default by either party may include, but are not limited to, the failure to pay or deliver payment under the derivative agreement, the failure to comply with or perform under the derivative agreement, bankruptcy, a merger without assumption of the derivative agreement, or in a merger, a surviving entity’s creditworthiness is materially weaker than the original party to the derivative agreement. Tabular Disclosure of Offsetting Derivatives The Company has elected not to offset derivative positions on the consolidated financial statements. The tables below present the effect on its financial position had the Company made the election to offset its derivative positions as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount March 31, 2020 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 6 ​ $ — ​ $ 6 ​ $ (3) ​ $ — ​ $ 3 (a) Amounts reconcile to the aggregate fair value of derivative assets in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Liabilities ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount March 31, 2020 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — ​ $ — ​ $ 3,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 142 ​ $ — ​ $ 142 ​ $ (3) ​ $ — ​ $ 139 (a) Amounts reconcile to the aggregate fair value of derivative liabilities in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.
United Dominion Realty L.P.
Entity information
DERIVATIVES AND HEDGING ACTIVITY	9. DERIVATIVES AND HEDGING ACTIVITY Risk Management Objective of Using Derivatives The Operating Partnership is exposed to certain risks arising from both its business operations and economic conditions. The General Partner principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The General Partner manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its debt funding and through the use of derivative financial instruments. Specifically, the General Partner enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The General Partner’s and the Operating Partnership’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the General Partner’s known or expected cash payments principally related to the General Partner’s borrowings Cash Flow Hedges of Interest Rate Risk The General Partner’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the General Partner primarily uses interest rate swaps and caps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the General Partner making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for an up-front premium The changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in Accumulated other comprehensive income/(loss), net Derivatives not designated as hedges are not speculative and are used to manage the Operating Partnership’s exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of GAAP. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings and resulted in no gain or loss for each of the three months ended March 31, 2020 and 2019. As of March 31, 2020, we had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps 1 ​ $ 19,880 ​ Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets As of March 31, 2020 and December 31, 2019, the fair value of the Operating Partnership’s derivative financial instruments was zero. Tabular Disclosure of the Effect of Derivative Instruments on the Consolidated Statements of Operations During the three months ended March 31, 2020 and 2019, the Operating Partnership’s derivative instruments did not impact the Consolidated Statement of Operations. Credit-risk-related Contingent Features The General Partner has agreements with its derivative counterparties that contain a provision where the General Partner could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the General Partner’s default on the indebtedness. The General Partner has certain agreements with some of its derivative counterparties that contain a provision where, in the event of default by the General Partner or the counterparty, the right of setoff may be exercised. Any amount payable to one party by the other party may be reduced by its setoff against any amounts payable by the other party. Events that give rise to default by either party may include, but are not limited to, the failure to pay or deliver payment under the derivative agreement, the failure to comply with or perform under the derivative agreement, bankruptcy, a merger without assumption of the derivative agreement, or in a merger, a surviving entity’s creditworthiness is materially weaker than the original party to the derivative agreement.

CAPITAL STRUCTURE (UNITED DOMIN

CAPITAL STRUCTURE (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
United Dominion Realty L.P.
Entity information
CAPITAL STRUCTURE	10. CAPITAL STRUCTURE General Partnership Units The General Partner has complete discretion to manage and control the operations and business of the Operating Partnership, which includes but is not limited to the acquisition and disposition of real property, construction of buildings and making capital improvements, and the borrowing of funds from outside lenders or UDR and its subsidiaries to finance such activities. The General Partner can generally authorize, issue, sell, redeem or purchase any OP Unit or securities of the Operating Partnership without the approval of the limited partners. The General Partner can also approve, with regard to the issuances of OP Units, the class or one or more series of classes, with designations, preferences, participating, optional or other special rights, powers and duties including rights, powers and duties senior to limited partnership interests without approval of any limited partners except holders of Class A Limited Partnership Units. There were 0.1 million General Partnership units outstanding at March 31, 2020 and December 31, 2019, all of which were held by UDR. Limited Partnership Units As of March 31, 2020 and December 31, 2019, there were 184.7 million and 184.0 million, respectively, of limited partnership units outstanding, of which 1.9 million were Class A Limited Partnership Units for both periods. UDR owned 176.1 million, or 95.3%, and 176.1 million, or 95.7%, of OP Units outstanding at March 31, 2020 and December 31, 2019, respectively, of which 0.1 million were Class A Limited Partnership Units for both periods. The remaining 8.6 million, or 4.7%, and 7.9 million, or 4.3%, of OP Units outstanding were held by non-affiliated partners at March 31, 2020 and December 31, 2019, respectively, of which 1.8 million were Class A Limited Partnership Units for both periods. Subject to the terms of the Operating Partnership Agreement, the limited partners have the right to require the Operating Partnership to redeem all or a portion of the OP Units held by the limited partner at a redemption price equal to and in the form of the Cash Amount (as defined in the Operating Partnership Agreement), provided that such OP Units have been outstanding for at least one year. UDR, as general partner of the Operating Partnership, may, in its sole discretion, purchase the OP Units by paying to the limited partner either the Cash Amount or the REIT Share Amount (generally one share of common stock of UDR for each OP Unit), as defined in the Operating Partnership Agreement. The non-affiliated limited partners’ capital is adjusted to redemption value at the end of each reporting period with the corresponding offset against UDR’s limited partner capital account based on the redemption rights noted above. The aggregate value upon redemption of the then-outstanding OP Units held by non-affiliated limited partners was $314.9 million and $366.4 million as of March 31, 2020 and December 31, 2019, respectively, based on the value of UDR’s common stock at each period end. A limited partner has no right to receive any distributions from the Operating Partnership on or after the date of redemption of its OP Units. Class A Limited Partnership Units Class A Limited Partnership Units have a cumulative, annual, non-compounded preferred return, which is equal to 8% based on a value of $16.61 per Class A Limited Partnership Unit. Holders of the Class A Limited Partnership Units exclusively possess certain voting rights. The Operating Partnership may not do the following without approval of the holders of the Class A Limited Partnership Units: (i) increase the authorized or issued amount of Class A Limited Partnership Units, (ii) reclassify any other partnership interest into Class A Limited Partnership Units, (iii) create, authorize or issue any obligations or security convertible into or the right to purchase Class A Limited Partnership Units, (iv) enter into a merger or acquisition, or (v) amend or modify the Operating Partnership Agreement in a manner that adversely affects the relative rights, preferences or privileges of the Class A Limited Partnership Units. The following table shows OP Units outstanding and OP Unit activity as of and for the three months ended March 31, 2020 ( units in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR, Inc. ​ ​ ​ Class A ​ ​ Class A ​ ​ ​ ​ Limited ​ Limited ​ Limited ​ Limited ​ General ​ ​ ​ ​ Partners ​ Partners ​ Partner ​ Partner ​ Partner ​ Total Ending balance at December 31, 2019 ​ 1,752 ​ 6,094 ​ 175,986 ​ 121 ​ 111 ​ 184,064 Vesting of LTIP Units ​ — ​ 772 ​ — ​ — ​ — ​ 772 Ending balance at March 31, 2020 1,752 6,866 175,986 121 111 184,836 ​ LTIP Units UDR grants long-term incentive plan units (“LTIP Units”) to certain employees and non-employee directors. The LTIP Units represent an ownership interest in the Operating Partnership and have voting and distribution rights consistent with OP Units. The LTIP Units are subject to the terms of UDR’s long-term incentive plan. Two classes of LTIP Units are granted, Class 1 LTIP Units and Class 2 LTIP Units. Class 1 LTIP Units are granted to certain employees and non-employee directors and vest over a period of up to four years. Class 2 LTIP Units are granted to certain employees and vest over a period from one Allocation of Profits and Losses Profit of the Operating Partnership is allocated in the following order: (i) to the General Partner and the Limited Partners in proportion to and up to the amount of cash distributions made during the year, and (ii) to the General Partner and Limited Partners in accordance with their percentage interests. Losses and depreciation and amortization expenses, non-recourse liabilities are allocated to the General Partner and Limited Partners in accordance with their percentage interests. Losses allocated to the Limited Partners are capped to the extent that such an allocation would not cause a deficit in the Limited Partners’ capital account. Such losses are, therefore, allocated to the General Partner. If any Partner’s capital balance were to fall into a deficit, any income and gains are allocated to each Partner sufficient to eliminate its negative capital balance

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
COMMITMENTS AND CONTINGENCIES	13. COMMITMENTS AND CONTINGENCIES Commitments Real Estate Commitments The following summarizes the Company’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Wholly-owned — under development 3 ​ $ 95,326 ​ $ 183,174 Wholly-owned — redevelopment 2 ​ ​ 17,660 ​ ​ 7,840 Joint ventures: ​ ​ Preferred equity investments 2 ​ ​ 34,647 (b) ​ 14,348 (c) Other investments ​ - ​ ​ 14,364 ​ ​ 23,700 (d) Total ​ $ 161,997 ​ $ 229,062 (a) Represents UDR’s investment as of March 31, 2020. (b) Represents UDR’s investment in Modera Lake Merritt and Thousand Oaks, which were under development as of March 31, 2020. (c) Represents UDR’s remaining commitment for Modera Lake Merritt and Thousand Oaks. (d) Represents UDR’s remaining commitment for other investment ventures. ​ Purchase Commitments In 2019, the Company entered into a contract to purchase a development land parcel located in King of Prussia, Pennsylvania for a purchase price of approximately $14.8 million. The Company made a $0.8 million deposit on the purchase, which is generally non-refundable other than due to a failure of closing conditions pursuant to the terms of the purchase agreement. The acquisition is expected to close in 2020, subject to completion of entitlement and customary closing conditions. Contingencies Litigation and Legal Matters The Company is subject to various legal proceedings and claims arising in the ordinary course of business. The Company cannot determine the ultimate liability with respect to such legal proceedings and claims at this time. The Company believes that such liability, to the extent not provided for through insurance or otherwise, will not have a material adverse effect on our financial condition, results of operations or cash flows.
United Dominion Realty L.P.
Entity information
COMMITMENTS AND CONTINGENCIES	11. COMMITMENTS AND CONTINGENCIES Commitments Real Estate Commitments The following summarizes the Operating Partnership’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ ​ ​ Operating Partnership's ​ ​ Properties ​ Investment ​ Remaining Commitment Real estate communities - redevelopment 1 ​ $ 9,150 ​ $ 5,850 ​ Contingencies Litigation and Legal Matters The Operating Partnership is subject to various legal proceedings and claims arising in the ordinary course of business. The Operating Partnership cannot determine the ultimate liability with respect to such legal proceedings and claims at this time. The General Partner believes that such liability, to the extent not provided for through insurance or otherwise, will not have a material adverse effect on the Operating Partnership’s financial condition, results of operations or cash flows.

REPORTABLE SEGMENTS (UNITED DOM

REPORTABLE SEGMENTS (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
REPORTABLE SEGMENTS	14. REPORTABLE SEGMENTS GAAP guidance requires that segment disclosures present the measure(s) used by the Chief Operating Decision Maker to decide how to allocate resources and for purposes of assessing such segments’ performance. UDR’s Chief Operating Decision Maker is comprised of several members of its executive management team who use several generally accepted industry financial measures to assess the performance of the business for our reportable operating segments. UDR owns and operates multifamily apartment communities that generate rental and other property related income through the leasing of apartment homes to a diverse base of tenants. The primary financial measures for UDR’s apartment communities are rental income and net operating income (“NOI”). Rental income represents gross market rent less adjustments for concessions, vacancy loss and bad debt. NOI is defined as rental income less direct property rental expenses. Rental expenses include real estate taxes, insurance, personnel, utilities, repairs and maintenance, administrative and marketing. Excluded from NOI is property management expense, which is calculated as 2.875% of property revenue to cover the regional supervision and accounting costs related to consolidated property operations, and land rent. UDR’s Chief Operating Decision Maker utilizes NOI as the key measure of segment profit or loss. UDR’s two reportable segments are Same-Store Communities Non-Mature Communities/Other ● Same-Store Communities represent those communities acquired, developed, and stabilized prior to January 1, 2019 and held as of March 31, 2020. A comparison of operating results from the prior year is meaningful as these communities were owned and had stabilized occupancy and operating expenses as of the beginning of the prior period, there is no plan to conduct substantial redevelopment activities, and the community is not held for disposition within the current year. A community is considered to have stabilized occupancy once it achieves 90% occupancy for at least three consecutive months. ● Non-Mature Communities/Other represent those communities that do not meet the criteria to be included in Same-Store Communities , including, but not limited to, recently acquired, developed and redeveloped communities, and the non-apartment components of mixed use properties. Management evaluates the performance of each of our apartment communities on a Same-Store Community Non-Mature Community/Other criteria under GAAP as each of our apartment communities generally has similar economic characteristics, facilities, services, and tenants. Therefore, the Company’s reportable segments have been aggregated by geography in a manner identical to that which is provided to the Chief Operating Decision Maker. Revenue is measured based on consideration specified in contracts with customers. The Company recognizes revenue when it satisfies a performance obligation by providing the services specified in a contract to the customer. All revenues are from external customers and no single tenant or related group of tenants contributed 10% or more of UDR’s total revenues during the three months ended March 31, 2020 and 2019. ​ The following is a description of the principal streams from which the Company generates its revenue: Lease Revenue ​ Lease revenue related to leases is recognized on an accrual basis when due from residents or tenants in accordance with ASC 842, Leases ​ Lease revenue also includes all pass-through revenue from retail and residential leases and common area maintenance reimbursements from retail leases. These services represent non-lease components in a contract as the Company transfers a service to the lessee other than the right to use the underlying asset. The Company has elected the practical expedient under the leasing standard to not separate lease and non-lease components from its resident and retail lease contracts as the timing and pattern of revenue recognition for the non-lease component and related lease component are the same and the combined single lease component would be classified as an operating lease. ​ Other Revenue ​ ​ Joint venture management and other fees ​ The Joint venture management and other fees Joint venture management and other fees ​ The following table details rental income and NOI for UDR’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (a) ​ 2020 2019 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 102,616 ​ $ 98,633 Mid-Atlantic Region ​ 56,085 ​ 54,300 Northeast Region ​ 30,942 ​ 30,193 Southeast Region ​ 30,677 ​ 29,531 Southwest Region ​ 16,626 ​ 16,077 Non-Mature Communities/Other ​ 74,676 ​ 30,169 Total segment and consolidated lease revenue ​ $ 311,622 ​ $ 258,903 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 2,774 ​ $ 3,076 Mid-Atlantic Region ​ 1,573 ​ 2,002 Northeast Region ​ 501 ​ 629 Southeast Region ​ 1,429 ​ 1,790 Southwest Region ​ 590 ​ 763 Non-Mature Communities/Other ​ 1,604 ​ 759 Total segment and consolidated other revenue ​ $ 8,471 ​ $ 9,019 ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 105,390 ​ $ 101,709 Mid-Atlantic Region ​ 57,658 ​ 56,302 Northeast Region ​ 31,443 ​ 30,822 Southeast Region ​ 32,106 ​ 31,321 Southwest Region ​ 17,216 ​ 16,840 Non-Mature Communities/Other ​ 76,280 ​ 30,928 Total segment and consolidated rental income ​ $ 320,093 ​ $ 267,922 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ Same-Store Communities (a) ​ ​ West Region ​ $ 79,823 ​ $ 76,984 Mid-Atlantic Region ​ 40,377 ​ 39,179 Northeast Region ​ 20,614 ​ 20,977 Southeast Region ​ 22,617 ​ 22,010 Southwest Region ​ 11,056 ​ 10,328 Non-Mature Communities/Other ​ 50,978 ​ 20,205 Total segment and consolidated NOI ​ 225,465 ​ 189,683 Reconciling items: ​ ​ Joint venture management and other fees ​ 1,388 ​ 2,751 Property management ​ (9,203) ​ (7,703) Other operating expenses ​ (4,966) ​ (5,646) Real estate depreciation and amortization ​ (155,476) ​ (112,468) General and administrative ​ (14,978) ​ (12,467) Casualty-related (charges)/recoveries, net ​ (1,251) ​ — Other depreciation and amortization ​ (2,025) ​ (1,656) Income/(loss) from unconsolidated entities ​ 3,367 ​ 49 Interest expense ​ (39,317) ​ (33,542) Interest income and other income/(expense), net ​ 2,700 ​ 9,813 Tax (provision)/benefit, net ​ (164) ​ (2,212) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) Net income/(loss) attributable to UDR, Inc. ​ $ 5,221 ​ $ 24,503 (a) Same-Store Community population consisted of 37,910 apartment homes. ​ The following table details the assets of UDR’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 3,704,480 ​ $ 3,696,544 Mid-Atlantic Region ​ 2,356,688 ​ 2,350,341 Northeast Region ​ 1,501,767 ​ 1,500,597 Southeast Region ​ 810,984 ​ 806,830 Southwest Region ​ 603,082 ​ 600,350 Non-Mature Communities/Other ​ 3,840,997 ​ 3,647,439 Total segment assets ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Total segment assets — net book value ​ 8,545,527 ​ 8,470,748 Reconciling items: ​ ​ Cash and cash equivalents ​ 980 ​ 8,106 Restricted cash ​ 21,949 ​ 25,185 Notes receivable, net ​ 151,543 ​ 153,650 Investment in and advances to unconsolidated joint ventures, net ​ 588,395 ​ 588,262 Operating lease right-of-use assets ​ ​ 203,410 ​ ​ 204,225 Other assets ​ 179,301 ​ 186,296 Total consolidated assets ​ $ 9,691,105 ​ $ 9,636,472 (a) Same-Store Community population consisted of 37,910 apartment homes. ​ Markets included in the above geographic segments are as follows: i. West Region — Orange County, San Francisco, Seattle, Los Angeles, Monterey Peninsula, Other Southern California and Portland ii. Mid-Atlantic Region — Metropolitan D.C., Richmond and Baltimore iii. Northeast Region — New York and Boston iv. Southeast Region — Orlando, Nashville, Tampa and Other Florida v. Southwest Region — Dallas, Austin and Denver
United Dominion Realty L.P.
Entity information
REPORTABLE SEGMENTS	12. REPORTABLE SEGMENTS GAAP guidance requires that segment disclosures present the measure(s) used by the Chief Operating Decision Maker to decide how to allocate resources and for purposes of assessing such segments’ performance. The Operating Partnership has the same Chief Operating Decision Maker as that of its parent, the General Partner. The Chief Operating Decision Maker consists of several members of UDR’s executive management team who use several generally accepted industry financial measures to assess the performance of the business for our reportable operating segments. The Operating Partnership owns and operates multifamily apartment communities throughout the United States that generate rental and other property related income through the leasing of apartment homes to a diverse base of tenants. The primary financial measures of the Operating Partnership’s apartment communities are rental income and net operating income (“NOI”), and are included in the Chief Operating Decision Maker’s assessment of the Operating Partnership’s performance on a consolidated basis. Rental income represents gross market rent less adjustments for concessions, vacancy loss and bad debt. NOI is defined as total revenues less direct property operating expenses. Rental expenses include real estate taxes, insurance, personnel, utilities, repairs and maintenance, administrative and marketing. Excluded from NOI are property management costs, which are the Operating Partnership’s allocable share of costs incurred by the General Partner for shared services of corporate level property management employees and related support functions and costs. The Chief Operating Decision Maker of the General Partner utilizes NOI as the key measure of segment profit or loss. The Operating Partnership’s two reportable segments are Same-Store Communities Non-Mature Communities/Other: ● Same-Store Communities represent those communities acquired, developed, and stabilized prior to January 1, 2019 and held as of March 31, 2020. A comparison of operating results from the prior year is meaningful as these communities were owned and had stabilized occupancy and operating expenses as of the beginning of the prior period, there is no plan to conduct substantial redevelopment activities, and the community is not held for disposition within the current year. A community is considered to have stabilized occupancy once it achieves 90% occupancy for at least three consecutive months. ● Non-Mature Communities/Other represent those communities that do not meet the criteria to be included in Same-Store Communities , including, but not limited to, recently acquired, developed and redeveloped communities, and the non-apartment components of mixed use properties. Management of the General Partner evaluates the performance of each of the Operating Partnership’s apartment communities on a Same-Store Community Non-Mature Community/Other All revenues are from external customers and no single tenant or related group of tenants contributed 10% or more of the Operating Partnership’s total revenues during the three months ended March 31, 2020 and 2019. The following is a description of the principal streams from which the Operating Partnership generates its revenue: Lease Revenue ​ Lease revenue related to leases is recognized on an accrual basis when due from residents or tenants in accordance with ASC 842, Leases ​ Lease revenue also includes all pass-through revenue from retail and residential leases and common area maintenance reimbursements from retail leases. These services represent non-lease components in a contract as the Operating Partnership transfers a service to the lessee other than the right to use the underlying asset. The Operating Partnership has elected the practical expedient under the leasing standard to not separate lease and non-lease components from its resident and retail lease contracts as the timing and pattern of revenue recognition for the non-lease component and related lease component are the same and the combined single lease component would be classified as an operating lease. ​ Other Revenue ​ ​ The following table details rental income and NOI for the Operating Partnership’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to OP unitholders (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (b) ​ ​ 2020 2019 ​ Reportable apartment home segment lease revenue ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 63,242 ​ $ 60,782 ​ Mid-Atlantic Region ​ 15,164 ​ 14,810 ​ Northeast Region ​ 8,229 ​ 7,972 ​ Southeast Region ​ 12,987 ​ 12,462 ​ Southwest Region ​ ​ 1,830 ​ ​ 1,924 ​ Non-Mature Communities/Other ​ 7,550 ​ 6,726 ​ Total segment and consolidated lease revenue ​ $ 109,002 ​ $ 104,676 ​ Reportable apartment home segment other revenue ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 1,779 ​ $ 1,995 ​ Mid-Atlantic Region ​ 431 ​ 535 ​ Northeast Region ​ 101 ​ 166 ​ Southeast Region ​ 644 ​ 775 ​ Southwest Region ​ ​ 71 ​ ​ 31 ​ Non-Mature Communities/Other ​ 137 ​ 156 ​ Total segment and consolidated other revenue ​ $ 3,163 ​ $ 3,658 ​ Total reportable apartment home segment rental income ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 65,021 ​ $ 62,777 ​ Mid-Atlantic Region ​ 15,595 ​ 15,345 ​ Northeast Region ​ 8,330 ​ 8,138 ​ Southeast Region ​ 13,631 ​ 13,237 ​ Southwest Region ​ ​ 1,901 ​ ​ 1,955 ​ Non-Mature Communities/Other ​ 7,687 ​ 6,882 ​ Total segment and consolidated rental income ​ $ 112,165 ​ $ 108,334 ​ Reportable apartment home segment NOI ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 49,493 ​ $ 47,797 ​ Mid-Atlantic Region ​ 10,796 ​ 10,524 ​ Northeast Region ​ 5,909 ​ 6,205 ​ Southeast Region ​ 9,550 ​ 9,257 ​ Southwest Region ​ ​ 1,391 ​ ​ 1,337 ​ Non-Mature Communities/Other ​ 4,416 ​ 4,019 ​ Total segment and consolidated NOI ​ 81,555 ​ 79,139 ​ Reconciling items: ​ ​ ​ Property management ​ (3,225) ​ (2,979) ​ Other operating expenses ​ (3,859) ​ (2,400) ​ Real estate depreciation and amortization ​ (35,300) ​ (34,654) ​ General and administrative ​ (5,308) ​ (4,661) ​ Casualty-related (charges)/recoveries, net ​ 2 ​ — ​ Income/(loss) from unconsolidated entities ​ (1,761) ​ (2,740) ​ Interest expense ​ (7,464) ​ (7,371) ​ Net (income)/loss attributable to noncontrolling interests ​ (522) ​ (388) ​ Net income/(loss) attributable to OP unitholders ​ $ 24,118 ​ $ 23,946 ​ (a) Same-Store Community population consisted of 15,941 apartment homes. ​ The following table details the assets of the Operating Partnership’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 2,017,542 ​ $ 2,011,495 Mid-Atlantic Region ​ 671,170 ​ 669,417 Northeast Region ​ 408,954 ​ 408,703 Southeast Region ​ 354,058 ​ 352,790 Southwest Region ​ ​ 144,640 ​ ​ 144,210 Non-Mature Communities/Other ​ 290,249 ​ 288,545 Total segment assets ​ 3,886,613 ​ 3,875,160 Accumulated depreciation ​ (1,831,814) ​ (1,796,568) Total segment assets - net book value ​ 2,054,799 ​ 2,078,592 Reconciling items: ​ ​ Cash and cash equivalents ​ 40 ​ 24 Restricted cash ​ 14,121 ​ 13,998 Investment in unconsolidated entities ​ 69,617 ​ 76,222 Operating lease right-of-use assets ​ ​ 204,723 ​ ​ 205,668 Other assets ​ 24,042 ​ 24,241 Total consolidated assets ​ $ 2,367,342 ​ $ 2,398,745 (a) Same-Store Community population consisted of 15,941 apartment homes. ​ Markets included in the above geographic segments are as follows: i. West Region — Orange County, San Francisco, Seattle, Los Angeles, Monterey Peninsula, Other Southern California and Portland ii. Mid-Atlantic Region — Metropolitan, D.C. and Baltimore iii. Northeast Region — New York and Boston iv. Southeast Region — Nashville, Tampa and Other Florida v. Southwest Region — Denver

SUBSEQUENT EVENT (UNITED DOMINI

SUBSEQUENT EVENT (UNITED DOMINION REALTY, L.P.)	3 Months Ended
	Mar. 31, 2020
Entity information
Subsequent Event	15. Subsequent Event ​ The Company is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business. The extent of the pandemic’s effect on our operational and financial performance will depend on future developments, including the duration, spread and intensity of the pandemic and the duration of government measures to mitigate the pandemic, all of which are uncertain and difficult to predict. Although the effect on our results of operations and cash flows through the date of issuance of our financial statements was not material, given the uncertainty, we cannot predict the effect on future periods, but the adverse impact on the Company's future financial condition, results of operations and cash flows could be material ​ ​
United Dominion Realty L.P.
Entity information
Subsequent Event	13. Subsequent Event ​ The Operating Partnership is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business. The extent of the pandemic’s effect on our operational and financial performance will depend on future developments, including the duration, spread and intensity of the pandemic and the duration of government measures to mitigate the pandemic, all of which are uncertain and difficult to predict. Although the effect on our results of operations and cash flows through the date of issuance of our financial statements was not material, given the uncertainty, we cannot predict the effect on future periods, but the adverse impact on the Operating Partnership's future financial condition, results of operations and cash flows could be material ​

SIGNIFICANT ACCOUNTING POLICI_6

SIGNIFICANT ACCOUNTING POLICIES (UNITED DOMINION REALTY, L.P.) (Policies)	3 Months Ended
	Mar. 31, 2020
Entity information
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, basis through a cumulative-effect adjustment to retained earnings of approximately $2.2 million on that date, which was primarily associated with our notes receivable. The Company concluded the cumulative effect was not material to our consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848)
Real Estate Sales Gain Recognition	Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Company generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Company will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Company sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Company will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Company will record a full gain or loss in the period the property is contributed. ​ To the extent that the Company acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Company will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Company will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Company will not recognize a gain or loss on consolidation of a property.
Principles of Consolidation	Principles of Consolidation The Company accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Company first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Company consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Company consolidates an entity when it controls the entity through ownership of a majority voting interest.
Income Taxes	Income Taxes Due to the structure of the Company as a REIT and the nature of the operations for the operating properties, no provision for federal income taxes has been provided for at UDR. Historically, the Company has generally incurred only state and local excise and franchise taxes. UDR has elected for certain consolidated subsidiaries to be treated as taxable REIT subsidiaries (“TRS”). Income taxes for our TRS are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rate is recognized in earnings in the period of the enactment date. The Company’s deferred tax assets/(liabilities) are generally the result of differing depreciable lives on capitalized assets, temporary differences between book and tax basis of assets and liabilities and timing of expense recognition for certain accrued liabilities. As of March 31, 2020 and December 31, 2019, UDR’s net deferred tax asset/(liability) was $(1.4) million and $(1.6) million, respectively. GAAP defines a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. GAAP also provides guidance on derecognition, classification, interest and penalties, accounting for interim periods, disclosure and transition. The Company recognizes its tax positions and evaluates them using a two-step process. First, UDR determines whether a tax position is more likely than not (greater than 50 percent probability) to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. Second, the Company will determine the amount of benefit to recognize and record the amount that is more likely than not to be realized upon ultimate settlement. The Company invests in assets that qualify for federal investment tax credits (“ITC”) through our TRS. An ITC reduces federal income taxes payable when qualifying depreciable property is acquired. The ITC is determined as a percentage of cost of the assets. The Company accounts for ITCs under the deferral method, under which the tax benefit from the ITC is deferred and amortized as a tax benefit into Tax (provision)/benefit, net Accounts payable, accrued expenses and other liabilities UDR had no material unrecognized tax benefit, accrued interest or penalties at March 31, 2020. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2016 through 2018 remain open to examination by tax jurisdictions to which we are subject. When applicable, UDR recognizes interest and/or penalties related to uncertain tax positions in Tax (provision)/benefit, net
Comprehensive Income/(Loss)	Comprehensive Income/(Loss) Comprehensive income/(loss), which is defined as the change in equity during each period from transactions and other events and circumstances from nonowner sources, including all changes in equity during a period except for those resulting from investments by or distributions to stockholders, is displayed in the accompanying Consolidated Statements of Comprehensive Income/(Loss). For the three months ended March 31, 2020 and 2019, the Company’s other comprehensive income/(loss) consisted of the gain/(loss) on derivative instruments that are designated as and qualify as cash flow hedges, (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) into earnings, and the allocation of other comprehensive income/(loss) to noncontrolling interests. The (gain)/loss on derivative instruments reclassified from other comprehensive income/(loss) is included in Interest expense Derivatives and Hedging Activity,
United Dominion Realty L.P.
Entity information
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, updated standard became effective for the Operating Partnership on January 1, 2020 and was adopted on a modified retrospective basis. However, as the Operating Partnership’s financial assets primarily relate to receivables arising from operating leases, the ASU did not have a material impact on the consolidated financial statements. Disclosures were updated pursuant to the requirements of the ASU. ​ In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) ​
Real Estate Sales Gain Recognition	Real Estate Sales Gain Recognition ​ For sale transactions resulting in a transfer of a controlling financial interest of a property, the Operating Partnership generally derecognizes the related assets and liabilities from its Consolidated Balance Sheets and records the gain or loss in the period in which the transfer of control occurs. If control of the property has not transferred to the counterparty, the criteria for derecognition are not met and the Operating Partnership will continue to recognize the related assets and liabilities on its Consolidated Balance Sheets. ​ Sale transactions to entities in which the Operating Partnership sells a controlling financial interest in a property but retains a noncontrolling interest are accounted for as partial sales. Partial sales resulting in a change in control are accounted for at fair value and a full gain or loss is recognized. Therefore, the Operating Partnership will record a gain or loss on the partial interest sold, and the initial measurement of our retained interest will be accounted for at fair value. ​ Sales of real estate to joint ventures or other noncontrolled investees are also accounted for at fair value and the Operating Partnership will record a full gain or loss in the period the property is contributed. ​ To the extent that the Operating Partnership acquires a controlling financial interest in a property that it previously accounted for as an equity method investment, the Operating Partnership will not remeasure its previously held interest if the acquisition is treated as an asset acquisition. The Operating Partnership will include the carrying amount of its previously held equity method interest along with the consideration paid and transaction costs incurred in determining the amounts to allocate to the related assets and liabilities acquired on its Consolidated Balance Sheets. When treated as an asset acquisition, the Operating Partnership will not recognize a gain or loss on consolidation of a property.
Principles of Consolidation	Principles of Consolidation The Operating Partnership accounts for subsidiary partnerships, joint ventures and other similar entities in which it holds an ownership interest in accordance with the consolidation guidance. The Operating Partnership first evaluates whether each entity is a variable interest entity (“VIE”). Under the VIE model, the Operating Partnership consolidates an entity when it has control to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the voting model, the Operating Partnership consolidates an entity when it controls the entity through ownership of a majority voting interest.
Income Taxes	Income Taxes The taxable income or loss of the Operating Partnership is reported on the tax returns of the partners. Accordingly, no provision has been made in the accompanying financial statements for federal or state income taxes on income that is passed through to the partners. However, any state or local revenue, excise or franchise taxes that result from the operating activities of the Operating Partnership are recorded at the entity level. The Operating Partnership’s tax returns are subject to examination by federal and state taxing authorities. Net income for financial reporting purposes differs from the net income for income tax reporting purposes primarily due to temporary differences, principally real estate depreciation and the tax deferral of certain gains on property sales. The differences in depreciation result from differences in the book and tax basis of certain real estate assets and the differences in the methods of depreciation and lives of the real estate assets. The Operating Partnership evaluates the accounting and disclosure of tax positions taken or expected to be taken in the course of preparing the Operating Partnership’s tax returns to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. Tax positions not deemed to meet the more-likely-than-not threshold would be recorded as a tax benefit or expense in the current year. Management of the Operating Partnership is required to analyze all open tax years, as defined by the statute of limitations, for all major jurisdictions, which include federal and certain states. The Operating Partnership has no examinations in progress and none are expected at this time. Management of the Operating Partnership has reviewed all open tax years (2016 through 2018) of tax jurisdictions and concluded there is no tax liability resulting from unrecognized tax benefits relating to uncertain income tax positions taken or expected to be taken in future tax returns.
Income/(Loss) Per Operating Partnership Unit	Income/(Loss) Per Operating Partnership Unit Basic income/(loss) per OP Unit is computed by dividing net income/(loss) attributable to the general and limited partner unitholders by the weighted average number of general and limited partner units outstanding during the year. Diluted income/(loss) per OP Unit reflects the potential dilution that could occur if securities or other contracts to issue OP Units were exercised or converted into OP Units or resulted in the issuance of OP Units and then shared in the income/(loss) of the Operating Partnership.

REAL ESTATE OWNED (UNITED DOM_2

REAL ESTATE OWNED (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Entity information
Summary of carrying amounts for real estate owned (at cost)	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 2,163,055 ​ $ 2,164,032 Depreciable property — held and used: ​ ​ Land improvements ​ 225,850 ​ 224,964 Building, improvements, and furniture, fixtures and equipment ​ 10,178,547 ​ 10,102,758 Real estate intangible assets ​ ​ 40,570 ​ ​ 40,570 Under development: ​ ​ Land and land improvements ​ 29,226 ​ 29,226 Building, improvements, and furniture, fixtures and equipment ​ 66,100 ​ 40,551 Real estate held for disposition: ​ ​ Land and land improvements ​ 16,245 ​ — Building, improvements, and furniture, fixtures and equipment ​ 98,405 ​ — Real estate owned ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Real estate owned, net ​ $ 8,545,527 ​ $ 8,470,748
United Dominion Realty L.P.
Entity information
Summary of carrying amounts for real estate owned (at cost)	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Land ​ $ 711,256 ​ $ 711,256 Depreciable property — held and used: ​ ​ ​ ​ Land improvements ​ ​ 97,807 ​ ​ 96,864 Buildings, improvements, and furniture, fixtures and equipment ​ 3,077,550 ​ 3,067,040 Real estate owned ​ 3,886,613 ​ 3,875,160 Accumulated depreciation ​ (1,831,814) ​ (1,796,568) Real estate owned, net ​ $ 2,054,799 ​ $ 2,078,592

UNCONSOLIDATED ENTITIES (UNIT_2

UNCONSOLIDATED ENTITIES (UNITED DOMINION REALTY, L.P.) Unconsolidated Entities (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Unconsolidated entities
Combined summary of balance sheets relating to unconsolidated joint ventures and partnerships	Combined summary balance sheets relating to the unconsolidated joint ventures’ and partnerships’ (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,868,502 $ 1,901,081 Cash and cash equivalents ​ 32,486 ​ 29,823 Other assets ​ ​ 180,893 ​ 172,941 Total assets $ 2,081,881 $ 2,103,845 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,136,306 ​ $ 1,148,048 Accounts payable and accrued liabilities ​ ​ 50,262 ​ ​ 55,114 Total liabilities ​ 1,186,568 ​ 1,203,162 Total equity $ 895,313 $ 900,683
Schedule of combined financial information relating to unconsolidated joint ventures and partnerships operations (not just proportionate share)	Combined summary financial information relating to the unconsolidated joint ventures’ and partnerships’ operations (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenues $ 41,314 $ 81,532 Property operating expenses ​ 15,297 ​ 30,312 Real estate depreciation and amortization ​ 16,243 ​ 29,580 Operating income/(loss) ​ 9,774 ​ ​ 21,640 Interest expense ​ (10,347) ​ (21,924) Net unrealized gain/(loss) on held investments ​ ​ — ​ ​ 1,522 Other income/(loss) ​ ​ (8) ​ ​ 103 Net income/(loss) $ (581) $ 1,341 (1)
United Dominion Realty L.P.
Unconsolidated entities
Combined summary of balance sheets relating to unconsolidated joint ventures and partnerships	Combined summary balance sheets relating to all of the DownREIT Partnership (not just our proportionate share) are presented below as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2020 2019 Total real estate, net $ 1,088,125 $ 1,106,703 Cash and cash equivalents ​ 20 ​ 20 Note receivable from the General Partner ​ 220,622 ​ 222,853 Other assets ​ 5,312 ​ 4,829 Total assets $ 1,314,079 $ 1,334,405 ​ ​ ​ ​ ​ ​ ​ Secured debt, net ​ $ 426,724 ​ $ 427,592 Other liabilities ​ 23,628 ​ 28,087 Total liabilities ​ 450,352 ​ 455,679 Total capital ​ $ 863,727 ​ $ 878,726 ​
Schedule of combined financial information relating to unconsolidated joint ventures and partnerships operations (not just proportionate share)	Combined summary financial information relating to all of the DownREIT Partnership (not just our proportionate share) is presented below for the three months ended March 31, 2020 and 2019 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2020 2019 Total revenue ​ $ 32,678 $ 31,606 Property operating expenses ​ (13,309) ​ (13,096) Real estate depreciation and amortization ​ (20,986) ​ (20,294) Operating income/(loss) ​ (1,617) ​ (1,784) Interest expense ​ (3,618) ​ (3,888) Other income/(loss) ​ 1,889 ​ 1,988 Net income/(loss) ​ $ (3,346) $ (3,684)

LEASES (UNITED DOMINION REALT_2

LEASES (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Lease
Lessee - Future minimum lease payments and total operating lease liabilities	Future minimum lease payments and total operating lease liabilities from our ground leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2020 ​ $ 9,330 2021 ​ ​ 12,442 2022 ​ ​ 12,442 2023 ​ ​ 12,442 2024 ​ ​ 12,442 Thereafter ​ ​ 455,221 Total future minimum lease payments (undiscounted) ​ ​ 514,319 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) Total operating lease liabilities (discounted) ​ $ 197,829
Lessee - components of operating lease expenses	The components of operating lease expenses were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2020 ​ 2019 Lease expense: ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,170 ​ $ 2,159 Variable lease expense (a) ​ ​ 43 ​ ​ 139 Total operating lease expense (b)(c) ​ $ 3,213 ​ $ 2,298 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.8 million and $0.7 million, respectively, and for the three months ended March 31, 2019 Operating lease right-of-use assets and Operating lease liabilities amortized by $0.2 million and $0.1 million, respectively. The Company recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization. ​
Lessor - Future minimum lease payments	Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 16,849 2021 ​ ​ 22,487 2022 ​ ​ 20,781 2023 ​ ​ 19,317 2024 ​ ​ 17,594 Thereafter ​ ​ 81,662 Total future minimum lease payments (a) ​ $ 178,690 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months or less.
United Dominion Realty L.P.
Lease
Lessee - Future minimum lease payments and total operating lease liabilities	Future minimum lease payments and total operating lease liabilities from our ground and equipment leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ground Leases ​ Equipment Leases ​ Total 2020 ​ $ 9,330 ​ $ 108 ​ $ 9,438 2021 ​ ​ 12,442 ​ ​ 147 ​ ​ 12,589 2022 ​ ​ 12,442 ​ ​ 150 ​ ​ 12,592 2023 ​ ​ 12,442 ​ ​ 153 ​ ​ 12,595 2024 ​ ​ 12,442 ​ ​ 156 ​ ​ 12,598 Thereafter ​ ​ 455,221 ​ ​ 795 ​ ​ 456,016 Total future minimum lease payments (undiscounted) ​ ​ 514,319 ​ ​ 1,509 ​ ​ 515,828 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (316,490) ​ ​ (189) ​ ​ (316,679) Total operating lease liabilities (discounted) ​ $ 197,829 ​ $ 1,320 ​ $ 199,149
Lessee - components of operating lease expenses	The components of operating lease expenses from our ground and equipment leases were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Ground lease expense: ​ ​ ​ ​ ​ ​ Contractual ground lease rent expense ​ $ 3,170 ​ $ 2,140 Variable ground lease expense (a) ​ ​ 43 ​ ​ 139 Total ground lease expense (b) ​ ​ 3,213 ​ ​ 2,279 Contractual equipment lease expense (b) ​ ​ 36 ​ ​ - Total operating lease expense (c) ​ $ 3,249 ​ $ 2,279 (a) Variable ground lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of income of the lessee. (b) Ground lease and equipment lease expense are reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the three months ended March 31, 2020, Operating lease right-of-use assets and Operating lease liabilities amortized by $0.9 million and $0.9 million, respectively. The Operating Partnership recorded $0.1 million and $0.1 million of total operating lease expense during the three months ended March 31, 2020 and 2019, respectively, due to the net impact of the amortization.
Lessor - Future minimum lease payments	Future minimum lease payments from our retail and commercial leases as of March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2020 ​ $ 5,678 2021 ​ ​ 7,311 2022 ​ ​ 6,688 2023 ​ ​ 6,361 2024 ​ ​ 5,693 Thereafter ​ ​ 14,807 Total future minimum lease payments (a) ​ $ 46,538 (a) We have excluded our apartment home leases from this table as our apartment home leases generally have initial terms of 12 months of less.

DEBT, NET (UNITED DOMINION RE_2

DEBT, NET (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Entity information
Schedule of debt instruments	The following is a summary of our secured and unsecured debt at March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ March 31, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2020 2019 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 883,249 ​ $ 884,869 3.61 % 5.9 15 Credit facilities (b) ​ 203,429 ​ 204,590 4.90 % 2.8 4 Deferred financing costs and other non-cash adjustments ​ 30,585 ​ 33,046 Total fixed rate secured debt, net ​ 1,117,263 ​ 1,122,505 3.85 % 5.3 19 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, net ​ 1,144,201 ​ 1,149,441 3.80 % 5.5 20 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2023 (d) (m) ​ 50,000 ​ — 1.75 % 2.8 Borrowings outstanding under unsecured commercial paper program due April 2020 (e) (m) (n) ​ ​ 215,000 ​ ​ 300,000 ​ 1.58 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2021 ​ 24,797 ​ 16,583 1.82 % 0.8 Term Loan due September 2023 (d) (m) ​ 35,000 ​ 35,000 2.48 % 3.5 Fixed Rate Debt ​ ​ 1.93% Term Loan due September 2023 (d) (m) ​ ​ 315,000 ​ 315,000 1.93 % 3.5 ​ ​ 3.75% Medium-Term Notes due July 2024 (net of discounts of $443 and $470, respectively) (g) (m) ​ 299,557 ​ 299,530 3.75 % 4.3 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 4.5 4.00% Medium-Term Notes due October 2025 (net of discounts of $379 and $396, respectively) (h) (m) ​ 299,621 ​ 299,604 4.00 % 5.5 2.95% Medium-Term Notes due September 2026 (m) ​ 300,000 ​ 300,000 2.95 % 6.4 3.50% Medium-Term Notes due July 2027 (net of discounts of $511 and $529, respectively) (m) ​ ​ 299,489 ​ ​ 299,471 ​ 3.50 % 7.3 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $924 and $954, respectively) (m) ​ ​ 299,076 ​ ​ 299,046 ​ 3.50 % 7.8 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $5 and $5, respectively) (i) (m) ​ ​ 299,995 ​ ​ 299,995 ​ 4.40 % 8.8 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $13,442 and $2,281, respectively) (j) (m) ​ ​ 613,442 ​ ​ 402,281 ​ 3.20 % 9.8 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of discounts of $1,099 and $1,123, respectively) (k) (m) ​ ​ 398,901 ​ ​ 398,877 ​ 3.00 % 11.4 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $1,287 and $1,309, respectively) (l) (m) ​ ​ 298,713 ​ ​ 298,691 ​ 3.10 % 14.6 ​ ​ Other ​ 12 ​ 13 Deferred financing costs ​ (23,310) ​ (21,652) Total Unsecured Debt, net ​ 3,740,937 ​ 3,558,083 3.29 % 7.5 Total Debt, net ​ $ 4,885,138 ​ $ 4,707,524 3.28 % 7.1
Schedule of aggregate maturities, including amortizing principal payments of secured and unsecured debt	The aggregate maturities, including amortizing principal payments on secured and unsecured debt, of total debt for the next ten calendar years subsequent to March 31, 2020 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2020 ​ $ 112,592 ​ $ — ​ $ 112,592 ​ $ 215,000 (a) $ 327,592 2021 ​ ​ 8,763 ​ ​ — ​ ​ 8,763 ​ ​ 24,797 ​ ​ 33,560 2022 ​ 9,159 ​ — ​ 9,159 ​ — ​ 9,159 2023 ​ 295,965 ​ — ​ 295,965 ​ 400,000 ​ 695,965 2024 ​ 95,280 ​ — ​ 95,280 ​ 315,644 ​ 410,924 2025 ​ 173,189 ​ — ​ 173,189 ​ 300,000 ​ 473,189 2026 ​ 51,070 ​ — ​ 51,070 ​ 300,000 ​ 351,070 2027 ​ 1,111 ​ — ​ 1,111 ​ 300,000 ​ 301,111 2028 ​ 122,465 ​ — ​ 122,465 ​ 300,000 ​ 422,465 2029 ​ 144,584 ​ — ​ 144,584 ​ 300,000 ​ 444,584 Thereafter ​ 72,500 ​ 27,000 ​ 99,500 ​ 1,300,000 ​ 1,399,500 Subtotal ​ 1,086,678 ​ 27,000 ​ 1,113,678 ​ 3,755,441 ​ 4,869,119 Non-cash (b) ​ 30,585 ​ (62) ​ 30,523 ​ (14,504) ​ 16,019 Total ​ $ 1,117,263 ​ $ 26,938 ​ $ 1,144,201 ​ $ 3,740,937 ​ $ 4,885,138 (a) All unsecured debt due in the remainder of 2020 is related to the Company’s commercial paper program. (b) Includes the unamortized balance of fair market value adjustments, premiums/discounts and deferred financing costs . The Company amortized $1.0 million and $1.0 million, respectively, during the three months ended March 31, 2020 and 2019, of deferred financing costs into Interest expense.
United Dominion Realty L.P.
Entity information
Schedule of debt instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of March 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ March 31, ​ December 31, ​ Average ​ Years to ​ Communities ​ ​ 2020 ​ 2019 ​ Interest Rate ​ Maturity ​ Encumbered Fixed Rate Debt ​ ​ Mortgage note payable ​ $ 72,500 ​ $ 72,500 3.10 % 9.8 1 Deferred financing costs ​ (356) ​ (365) Total fixed rate secured debt, net ​ 72,144 ​ 72,135 3.10 % 9.8 1 Variable Rate Debt ​ ​ Tax-exempt secured note payable ​ $ 27,000 ​ $ 27,000 1.91 % 12.0 1 Deferred financing costs ​ (62) ​ (64) Total variable rate secured debt, net ​ 26,938 ​ 26,936 1.91 % 12.0 1 Total Secured Debt, Net ​ $ 99,082 ​ $ 99,071 2.83 % 10.4 2

RELATED PARTY TRANSACTIONS (U_2

RELATED PARTY TRANSACTIONS (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
United Dominion Realty L.P.
Related Party Transaction [Line Items]
Schedule of Notes payable due to General Partner	The following table summarizes the Operating Partnership’s Notes payable due to the General Partner as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding ​ March 31, ​ March 31, December 31, ​ ​ 2020 ​ 2020 ​ 2019 Note due August 2021 5.34 % ​ $ 5,500 ​ $ 5,500 Note due December 2023 5.18 % ​ 83,196 ​ 83,196 Note due April 2026 4.12 % ​ 184,638 ​ 184,638 Note due November 2028 ​ 4.69 % ​ ​ 133,205 ​ ​ 133,205 Note due December 2028 (a) ​ 3.28 % ​ ​ 229,199 ​ ​ 230,694 Total notes payable due to the General Partner ​ ​ $ 635,738 ​ $ 637,233 (a) There is no limit on the total commitments under this unsecured revolving note. Interest is incurred on the unpaid principal balance at a variable interest rate equivalent to the General Partner’s weighted average interest rate on borrowings, or 3.28% as of March 31, 2020. The note matures on December 1, 2028. To the extent there is an outstanding principal balance on the revolving note payable, the General Partner, at its discretion, can demand payment at any time prior to the stated maturity date of the note.

FAIR VALUE OF DERIVATIVES AND_5

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Entity information
Schedule of estimated fair values	The estimated fair values of the Company’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 Total assets ​ $ 151,543 ​ $ 160,515 ​ $ — ​ $ — ​ $ 160,515 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 3,075 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 903,243 ​ ​ 908,088 ​ ​ — ​ ​ — ​ ​ 908,088 Credit facilities ​ 216,181 ​ 213,026 ​ — ​ — ​ 213,026 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ Revolving credit facility ​ ​ 50,000 ​ ​ 50,000 ​ ​ — ​ ​ — ​ ​ 50,000 Working capital credit facility ​ ​ 24,797 ​ ​ 24,797 ​ ​ — ​ ​ — ​ ​ 24,797 Commercial paper program ​ ​ 215,000 ​ ​ 215,000 ​ ​ — ​ ​ — ​ ​ 215,000 Unsecured notes ​ ​ 3,474,450 ​ ​ 3,466,082 ​ ​ — ​ ​ — ​ ​ 3,466,082 Total liabilities ​ $ 4,913,746 ​ $ 4,907,068 ​ $ — ​ $ 3,075 ​ $ 4,903,993 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 819,133 ​ $ 819,133 ​ $ — ​ $ 819,133 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ Total ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ Active ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable (b) ​ $ 153,650 ​ $ 160,197 ​ $ — ​ $ — ​ $ 160,197 Derivatives - Interest rate contracts (c) ​ 6 ​ 6 ​ — ​ 6 ​ — Total assets ​ $ 153,656 ​ $ 160,203 ​ $ — ​ $ 6 ​ $ 160,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives - Interest rate contracts (c) ​ $ 142 ​ $ 142 ​ $ — ​ $ 142 ​ $ — Secured debt instruments - fixed rate: (d) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ ​ 906,228 ​ ​ 898,329 ​ ​ — ​ ​ — ​ ​ 898,329 Credit facilities ​ 218,490 ​ 213,661 ​ — ​ — ​ 213,661 Secured debt instruments - variable rate: (d) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (d) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 16,583 ​ ​ 16,583 ​ ​ — ​ ​ — ​ ​ 16,583 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 3,263,152 ​ ​ 3,397,622 ​ ​ — ​ ​ — ​ ​ 3,397,622 Total liabilities ​ $ 4,731,595 ​ $ 4,853,337 ​ $ — ​ $ 142 ​ $ 4,853,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (e) ​ $ 1,018,665 ​ $ 1,018,665 ​ $ — ​ $ 1,018,665 ​ $ — (a) Balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) See Note 11, Derivatives and Hedging Activity . (d) See Note 7, Secured and Unsecured Debt, Net . (e) See Note 9, Noncontrolling Interests.
United Dominion Realty L.P.
Entity information
Schedule of estimated fair values	The estimated fair values of the Operating Partnership’s financial instruments either recorded or disclosed on a recurring basis as of March 31, 2020 and December 31, 2019 are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at March 31, 2020, Using ​ Total ​ ​ Quoted ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ Markets ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ for Identical ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ Assets or ​ Observable ​ Unobservable ​ ​ March 31, ​ March 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2020 (a) ​ 2020 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ Secured debt instrument - fixed rate: (b) ​ ​ ​ ​ ​ Mortgage note payable ​ $ 72,500 ​ $ 73,663 ​ $ — ​ $ — ​ $ 73,663 Secured debt instrument - variable rate: (b) ​ ​ ​ ​ ​ ​ Tax-exempt secured note payable ​ ​ 27,000 ​ ​ 27,000 ​ ​ — ​ ​ — ​ ​ 27,000 Total liabilities ​ $ 99,500 ​ $ 100,663 ​ $ — ​ $ — ​ $ 100,663 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2019, Using ​ ​ ​ ​ ​ Quoted ​ ​ ​ ​ ​ ​ Total ​ ​ ​ ​ Prices in ​ ​ ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Active ​ ​ ​ ​ ​ ​ ​ ​ Amount in ​ ​ ​ ​ Markets ​ ​ ​ ​ ​ ​ ​ ​ Statement of ​ ​ ​ ​ for Identical ​ Significant ​ ​ ​ ​ ​ Financial ​ Fair Value ​ Assets ​ Other ​ Significant ​ ​ Position at ​ Estimate at ​ or ​ Observable ​ Unobservable ​ ​ December 31, ​ December 31, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2019 (a) ​ 2019 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (b) ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 72,500 ​ $ 71,976 ​ $ — ​ $ — ​ $ 71,976 Secured debt instrument - variable rate: (b) ​ ​ ​ ​ ​ ​ Tax-exempt secured note payable ​ $ 27,000 ​ $ 27,000 ​ $ — ​ $ — ​ $ 27,000 Total liabilities ​ $ 99,500 ​ $ 98,976 ​ $ — ​ $ — ​ $ 98,976 (a) Balances exclude deferred financing costs. (b) See Note 6, Debt, Net. ​

DERIVATIVES AND HEDGING ACTIV_9

DERIVATIVES AND HEDGING ACTIVITY (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Entity information
Schedule of outstanding interest rate derivatives	As of March 31, 2020, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges of interest rate risk ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ Product ​ Instruments ​ Notional Interest rate swaps ​ 1 ​ $ 315,000 ​ Derivatives not designated as hedges are not speculative and are used to manage the Company’s exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of GAAP. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings and resulted in no gain or loss for both the three months ended March 31, 2020 and 2019. As of March 31, 2020, the Company had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps ​ 1 ​ $ 19,880
Fair value of Company's derivative financial instruments and their classification on Consolidated Balance Sheets	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheets as of March 31, 2020 and December 31, 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ March 31, ​ December 31, ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ — ​ $ 6 ​ $ 3,075 ​ $ 142
Effect of Company's derivative financial instruments on Consolidated Statements of Operations	The tables below present the effect of the Company’s derivative financial instruments on the Consolidated Statements of Operations for the three months ended March 31, 2020 and 2019 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain/(Loss) Recognized in ​ ​ ​ ​ Gain/(Loss) Reclassified ​ Interest expense ​ ​ Unrealized holding gain/(loss) ​ from Accumulated OCI into ​ (Amount Excluded from ​ ​ Recognized in OCI ​ Interest expense ​ Effectiveness Testing) Derivatives in Cash Flow Hedging Relationships 2020 2019 2020 2019 2020 2019 Three Months Ended March 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ (2,917) ​ $ (2,210) ​ $ (357) ​ $ 945 ​ $ — ​ $ —
Effect of Company's derivatives not designated as hedging instruments on the Consolidated Statements of Operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Total amount of Interest expense ​ $ 39,317 ​ $ 33,542 ​
Offsetting of Derivative Assets	The Company has elected not to offset derivative positions on the consolidated financial statements. The tables below present the effect on its financial position had the Company made the election to offset its derivative positions as of March 31, 2020 and December 31, 2019 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount March 31, 2020 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 6 ​ $ — ​ $ 6 ​ $ (3) ​ $ — ​ $ 3 (a) Amounts reconcile to the aggregate fair value of derivative assets in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.
Offsetting of Derivative Liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Liabilities ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheet ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount March 31, 2020 ​ $ 3,075 ​ $ — ​ $ 3,075 ​ $ — ​ $ — ​ $ 3,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ $ 142 ​ $ — ​ $ 142 ​ $ (3) ​ $ — ​ $ 139 (a) Amounts reconcile to the aggregate fair value of derivative liabilities in the “Tabular Disclosure of Fair Values of Derivative Instruments on the Consolidated Balance Sheets” located in this footnote.
United Dominion Realty L.P.
Entity information
Schedule of outstanding interest rate derivatives	As of March 31, 2020, we had the following outstanding derivatives that were not designated as hedges in qualifying hedging relationships ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ Number of ​ ​ Product ​ Instruments ​ Notional Interest rate caps 1 ​ $ 19,880 ​

CAPITAL STRUCTURE (UNITED DOM_2

CAPITAL STRUCTURE (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
United Dominion Realty L.P.
Entity information
Schedule of limited partners' capital account by class	The following table shows OP Units outstanding and OP Unit activity as of and for the three months ended March 31, 2020 ( units in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR, Inc. ​ ​ ​ Class A ​ ​ Class A ​ ​ ​ ​ Limited ​ Limited ​ Limited ​ Limited ​ General ​ ​ ​ ​ Partners ​ Partners ​ Partner ​ Partner ​ Partner ​ Total Ending balance at December 31, 2019 ​ 1,752 ​ 6,094 ​ 175,986 ​ 121 ​ 111 ​ 184,064 Vesting of LTIP Units ​ — ​ 772 ​ — ​ — ​ — ​ 772 Ending balance at March 31, 2020 1,752 6,866 175,986 121 111 184,836

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Loss Contingencies [Line Items]
Summary of real estate commitments	The following summarizes the Company’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Wholly-owned — under development 3 ​ $ 95,326 ​ $ 183,174 Wholly-owned — redevelopment 2 ​ ​ 17,660 ​ ​ 7,840 Joint ventures: ​ ​ Preferred equity investments 2 ​ ​ 34,647 (b) ​ 14,348 (c) Other investments ​ - ​ ​ 14,364 ​ ​ 23,700 (d) Total ​ $ 161,997 ​ $ 229,062 (a) Represents UDR’s investment as of March 31, 2020. (b) Represents UDR’s investment in Modera Lake Merritt and Thousand Oaks, which were under development as of March 31, 2020. (c) Represents UDR’s remaining commitment for Modera Lake Merritt and Thousand Oaks. (d) Represents UDR’s remaining commitment for other investment ventures.
United Dominion Realty L.P.
Loss Contingencies [Line Items]
Summary of real estate commitments	The following summarizes the Operating Partnership’s real estate commitments at March 31, 2020 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ ​ ​ Operating Partnership's ​ ​ Properties ​ Investment ​ Remaining Commitment Real estate communities - redevelopment 1 ​ $ 9,150 ​ $ 5,850 ​

REPORTABLE SEGMENTS (UNITED D_2

REPORTABLE SEGMENTS (UNITED DOMINION REALTY, L.P.) (Tables)	3 Months Ended
	Mar. 31, 2020
Entity information
Summary of rental income and NOI for the Operating Partnerships reportable segments and reconciliation of NOI to Net income/(loss)	The following table details rental income and NOI for UDR’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (a) ​ 2020 2019 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 102,616 ​ $ 98,633 Mid-Atlantic Region ​ 56,085 ​ 54,300 Northeast Region ​ 30,942 ​ 30,193 Southeast Region ​ 30,677 ​ 29,531 Southwest Region ​ 16,626 ​ 16,077 Non-Mature Communities/Other ​ 74,676 ​ 30,169 Total segment and consolidated lease revenue ​ $ 311,622 ​ $ 258,903 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 2,774 ​ $ 3,076 Mid-Atlantic Region ​ 1,573 ​ 2,002 Northeast Region ​ 501 ​ 629 Southeast Region ​ 1,429 ​ 1,790 Southwest Region ​ 590 ​ 763 Non-Mature Communities/Other ​ 1,604 ​ 759 Total segment and consolidated other revenue ​ $ 8,471 ​ $ 9,019 ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 105,390 ​ $ 101,709 Mid-Atlantic Region ​ 57,658 ​ 56,302 Northeast Region ​ 31,443 ​ 30,822 Southeast Region ​ 32,106 ​ 31,321 Southwest Region ​ 17,216 ​ 16,840 Non-Mature Communities/Other ​ 76,280 ​ 30,928 Total segment and consolidated rental income ​ $ 320,093 ​ $ 267,922 ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ Same-Store Communities (a) ​ ​ West Region ​ $ 79,823 ​ $ 76,984 Mid-Atlantic Region ​ 40,377 ​ 39,179 Northeast Region ​ 20,614 ​ 20,977 Southeast Region ​ 22,617 ​ 22,010 Southwest Region ​ 11,056 ​ 10,328 Non-Mature Communities/Other ​ 50,978 ​ 20,205 Total segment and consolidated NOI ​ 225,465 ​ 189,683 Reconciling items: ​ ​ Joint venture management and other fees ​ 1,388 ​ 2,751 Property management ​ (9,203) ​ (7,703) Other operating expenses ​ (4,966) ​ (5,646) Real estate depreciation and amortization ​ (155,476) ​ (112,468) General and administrative ​ (14,978) ​ (12,467) Casualty-related (charges)/recoveries, net ​ (1,251) ​ — Other depreciation and amortization ​ (2,025) ​ (1,656) Income/(loss) from unconsolidated entities ​ 3,367 ​ 49 Interest expense ​ (39,317) ​ (33,542) Interest income and other income/(expense), net ​ 2,700 ​ 9,813 Tax (provision)/benefit, net ​ (164) ​ (2,212) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (313) ​ (2,057) Net (income)/loss attributable to noncontrolling interests ​ (6) ​ (42) Net income/(loss) attributable to UDR, Inc. ​ $ 5,221 ​ $ 24,503 (a) Same-Store Community population consisted of 37,910 apartment homes. ​
Details of assets of the Operating Partnership's reportable segments	The following table details the assets of UDR’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 3,704,480 ​ $ 3,696,544 Mid-Atlantic Region ​ 2,356,688 ​ 2,350,341 Northeast Region ​ 1,501,767 ​ 1,500,597 Southeast Region ​ 810,984 ​ 806,830 Southwest Region ​ 603,082 ​ 600,350 Non-Mature Communities/Other ​ 3,840,997 ​ 3,647,439 Total segment assets ​ 12,817,998 ​ 12,602,101 Accumulated depreciation ​ (4,272,471) ​ (4,131,353) Total segment assets — net book value ​ 8,545,527 ​ 8,470,748 Reconciling items: ​ ​ Cash and cash equivalents ​ 980 ​ 8,106 Restricted cash ​ 21,949 ​ 25,185 Notes receivable, net ​ 151,543 ​ 153,650 Investment in and advances to unconsolidated joint ventures, net ​ 588,395 ​ 588,262 Operating lease right-of-use assets ​ ​ 203,410 ​ ​ 204,225 Other assets ​ 179,301 ​ 186,296 Total consolidated assets ​ $ 9,691,105 ​ $ 9,636,472 (a) Same-Store Community population consisted of 37,910 apartment homes. ​
United Dominion Realty L.P.
Entity information
Summary of rental income and NOI for the Operating Partnerships reportable segments and reconciliation of NOI to Net income/(loss)	The following table details rental income and NOI for the Operating Partnership’s reportable segments for the three months ended March 31, 2020 and 2019, and reconciles NOI to Net income/(loss) attributable to OP unitholders (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, (b) ​ ​ 2020 2019 ​ Reportable apartment home segment lease revenue ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 63,242 ​ $ 60,782 ​ Mid-Atlantic Region ​ 15,164 ​ 14,810 ​ Northeast Region ​ 8,229 ​ 7,972 ​ Southeast Region ​ 12,987 ​ 12,462 ​ Southwest Region ​ ​ 1,830 ​ ​ 1,924 ​ Non-Mature Communities/Other ​ 7,550 ​ 6,726 ​ Total segment and consolidated lease revenue ​ $ 109,002 ​ $ 104,676 ​ Reportable apartment home segment other revenue ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 1,779 ​ $ 1,995 ​ Mid-Atlantic Region ​ 431 ​ 535 ​ Northeast Region ​ 101 ​ 166 ​ Southeast Region ​ 644 ​ 775 ​ Southwest Region ​ ​ 71 ​ ​ 31 ​ Non-Mature Communities/Other ​ 137 ​ 156 ​ Total segment and consolidated other revenue ​ $ 3,163 ​ $ 3,658 ​ Total reportable apartment home segment rental income ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 65,021 ​ $ 62,777 ​ Mid-Atlantic Region ​ 15,595 ​ 15,345 ​ Northeast Region ​ 8,330 ​ 8,138 ​ Southeast Region ​ 13,631 ​ 13,237 ​ Southwest Region ​ ​ 1,901 ​ ​ 1,955 ​ Non-Mature Communities/Other ​ 7,687 ​ 6,882 ​ Total segment and consolidated rental income ​ $ 112,165 ​ $ 108,334 ​ Reportable apartment home segment NOI ​ ​ ​ Same-Store Communities (a) ​ ​ ​ West Region ​ $ 49,493 ​ $ 47,797 ​ Mid-Atlantic Region ​ 10,796 ​ 10,524 ​ Northeast Region ​ 5,909 ​ 6,205 ​ Southeast Region ​ 9,550 ​ 9,257 ​ Southwest Region ​ ​ 1,391 ​ ​ 1,337 ​ Non-Mature Communities/Other ​ 4,416 ​ 4,019 ​ Total segment and consolidated NOI ​ 81,555 ​ 79,139 ​ Reconciling items: ​ ​ ​ Property management ​ (3,225) ​ (2,979) ​ Other operating expenses ​ (3,859) ​ (2,400) ​ Real estate depreciation and amortization ​ (35,300) ​ (34,654) ​ General and administrative ​ (5,308) ​ (4,661) ​ Casualty-related (charges)/recoveries, net ​ 2 ​ — ​ Income/(loss) from unconsolidated entities ​ (1,761) ​ (2,740) ​ Interest expense ​ (7,464) ​ (7,371) ​ Net (income)/loss attributable to noncontrolling interests ​ (522) ​ (388) ​ Net income/(loss) attributable to OP unitholders ​ $ 24,118 ​ $ 23,946 ​ (a) Same-Store Community population consisted of 15,941 apartment homes. ​
Details of assets of the Operating Partnership's reportable segments	The following table details the assets of the Operating Partnership’s reportable segments as of March 31, 2020 and December 31, 2019 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2020 ​ 2019 Reportable apartment home segment assets ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 2,017,542 ​ $ 2,011,495 Mid-Atlantic Region ​ 671,170 ​ 669,417 Northeast Region ​ 408,954 ​ 408,703 Southeast Region ​ 354,058 ​ 352,790 Southwest Region ​ ​ 144,640 ​ ​ 144,210 Non-Mature Communities/Other ​ 290,249 ​ 288,545 Total segment assets ​ 3,886,613 ​ 3,875,160 Accumulated depreciation ​ (1,831,814) ​ (1,796,568) Total segment assets - net book value ​ 2,054,799 ​ 2,078,592 Reconciling items: ​ ​ Cash and cash equivalents ​ 40 ​ 24 Restricted cash ​ 14,121 ​ 13,998 Investment in unconsolidated entities ​ 69,617 ​ 76,222 Operating lease right-of-use assets ​ ​ 204,723 ​ ​ 205,668 Other assets ​ 24,042 ​ 24,241 Total consolidated assets ​ $ 2,367,342 ​ $ 2,398,745 (a) Same-Store Community population consisted of 15,941 apartment homes. ​

CONSOLIDATION AND BASIS OF PR_2

CONSOLIDATION AND BASIS OF PRESENTATION - GP Units (UNITED DOMINION REALTY, L.P.) (Details)	3 Months Ended
	Mar. 31, 2020itemcommunityshares	Mar. 31, 2019	Dec. 31, 2019shares
Basis of presentation
Number of real estate properties | community	150
Number of apartments owned (in apartments homes) | item	47,579
Operating Partnership outstanding units	184.8
Operating Partnership units outstanding related to limited partner	184,836,000		184,064,000
United Dominion Realty L.P.
Basis of presentation
Rental revenues percent of General Partner's consolidated rental revenues	35.00%	40.00%
General Partners' ownership (as a percent)	95.30%
OP units outstanding related to general partner	100,000
Operating Partnership units outstanding related to limited partner	176.2
United Dominion Realty L.P.
Basis of presentation
Number of real estate properties | community	52
Number of markets operating within (in markets) | item	15
Number of apartments owned (in apartments homes) | item	16,434
Operating Partnership outstanding units	184,800,000		184,100,000
OP units outstanding related to general partner	110,883		110,883
Operating Partnership units outstanding related to limited partner	184,724,677		183,952,659
UDR, Inc.
Basis of presentation
General Partners' ownership (as a percent)	57.40%
Operating Partnership outstanding units	18.6
Operating Partnership units outstanding related to limited partner	176,100,000		176,100,000
Percentage of units outstanding in Partnership	95.30%		95.70%
UDR, Inc. | United Dominion Realty L.P.
Basis of presentation
General Partners' ownership (as a percent)	95.30%
Operating Partnership outstanding units			176,200,000
OP units outstanding related to general partner	176.2
Percentage of units outstanding in Partnership			95.70%
Non-affiliated Partners
Basis of presentation
Operating Partnership outstanding units	13.8
Operating Partnership units outstanding related to limited partner	8.6
Percentage of units outstanding in Partnership	4.70%
Non-affiliated Partners | United Dominion Realty L.P.
Basis of presentation
Operating Partnership outstanding units			7.9
Operating Partnership units outstanding related to limited partner	8.6
Percentage of units outstanding in Partnership	4.70%		4.30%
Class A Limited Partner | United Dominion Realty L.P.
Basis of presentation
Operating Partnership units outstanding related to limited partner	1,900,000		1,900,000
Class A Limited Partner | UDR, Inc.
Basis of presentation
Operating Partnership units outstanding related to limited partner	100,000		100,000
Non-affiliated Partners | United Dominion Realty L.P.
Basis of presentation
Operating Partnership units outstanding related to limited partner	8,600,000		7,900,000
Percentage of units outstanding in Partnership	4.70%		4.30%
Non-affiliated Partners | Class A Limited Partner
Basis of presentation
Operating Partnership units outstanding related to limited partner	1,752,000		1,752,000

SIGNIFICANT ACCOUNTING POLICI_7

SIGNIFICANT ACCOUNTING POLICIES (UNITED DOMINION REALTY, L.P.) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accounting policies
Operating lease right-of-use assets	$ 203,410		$ 204,225
Operating lease liabilities	197,829		198,558
Development costs excluding direct costs and capitalized interest	6,900	$ 3,300
Interest capitalized during period	1,400	1,100
United Dominion Realty L.P.
Accounting policies
Operating lease right-of-use assets	204,723		205,668
Operating lease liabilities	199,149		$ 200,001
Development costs excluding direct costs and capitalized interest	400
Unrecognized Tax Benefits	0
United Dominion Realty L.P. | Maximum
Accounting policies
Development costs excluding direct costs and capitalized interest		100
Interest capitalized during period	$ 100	$ 100

REAL ESTATE OWNED (UNITED DOM_3

REAL ESTATE OWNED (UNITED DOMINION REALTY, L.P.) - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned
Land	$ 2,163,055	$ 2,164,032
Depreciable property - held and used:
Land improvements	225,850	224,964
Building, improvements, and furniture, fixtures and equipment	10,178,547	10,102,758
Real estate owned	12,817,998	12,602,101
Accumulated depreciation	(4,272,471)	(4,131,353)
Total real estate owned, net of accumulated depreciation	8,545,527	8,470,748
United Dominion Realty L.P.
Real estate owned
Land	711,256	711,256
Depreciable property - held and used:
Land improvements	97,807	96,864
Building, improvements, and furniture, fixtures and equipment	3,077,550	3,067,040
Real estate owned	3,886,613	3,875,160
Accumulated depreciation	(1,831,814)	(1,796,568)
Total real estate owned, net of accumulated depreciation	$ 2,054,799	$ 2,078,592

REAL ESTATE OWNED (UNITED DOM_4

REAL ESTATE OWNED (UNITED DOMINION REALTY, L.P.) - Acquisitions and Dispositions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)itemcommunitystate	Mar. 31, 2019USD ($)
Real Estate Owned Disclosure
Number of communities owned (in communities) | community	150
Number of states in which there are owned and consolidated communities | state	13
Development costs excluding direct costs and capitalized interest	$ 6.9	$ 3.3
Number of apartments owned (in apartments homes) | item	47,579
Interest capitalized during period	$ 1.4	1.1
United Dominion Realty L.P.
Real Estate Owned Disclosure
Number of communities owned (in communities) | community	52
Number of states in which there are owned and consolidated communities | state	9
Development costs excluding direct costs and capitalized interest	$ 0.4
Number of apartments owned (in apartments homes) | item	16,434
United Dominion Realty L.P. | Maximum
Real Estate Owned Disclosure
Development costs excluding direct costs and capitalized interest		0.1
Interest capitalized during period	$ 0.1	$ 0.1

UNCONSOLIDATED ENTITIES (UNIT_3

UNCONSOLIDATED ENTITIES (UNITED DOMINION REALTY, L.P.) - Summary Financial Information (Details) - UDR Lighthouse DownREIT L.P. - United Dominion Realty L.P. - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Total real estate, net	$ 1,088,125		$ 1,106,703
Cash and cash equivalents	20		20
Note receivable from the General Partner	220,622		222,853
Other assets	5,312		4,829
Total assets	1,314,079		1,334,405
Secured debt, net	426,724		427,592
Other liabilities	23,628		28,087
Liabilities	450,352		455,679
Total capital	863,727		$ 878,726
Total revenues	32,678	$ 31,606
Property operating expenses	(13,309)	(13,096)
Real estate depreciation and amortization	(20,986)	(20,294)
Operating income/(loss)	(1,617)	(1,784)
Interest expense	(3,618)	(3,888)
Other income/(loss)	1,889	1,988
Net income /(loss)	$ (3,346)	$ (3,684)

UNCONSOLIDATED ENTITIES (UNIT_4

UNCONSOLIDATED ENTITIES (UNITED DOMINION REALTY, L.P.) - Additional Information (Details) $ in Thousands	Mar. 31, 2020USD ($)itemcommunity	Dec. 31, 2019USD ($)
Unconsolidated entities
Number of real estate properties | community	150
Number of apartment homes owned and consolidated | item	47,579
Equity Method Investments | $	$ 585,091	$ 585,490
United Dominion Realty L.P.
Unconsolidated entities
Number of real estate properties | community	52
Number of apartment homes owned and consolidated | item	16,434
Equity Method Investments | $	$ 69,617	76,222
United Dominion Realty L.P. | UDR Lighthouse DownREIT L.P.
Unconsolidated entities
Number of real estate properties | community	12
Number of apartment homes owned and consolidated | item	5,657
Equity Method Investments | $	$ 69,600	$ 76,200

LEASES (UNITED DOMINION REALT_3

LEASES (UNITED DOMINION REALTY, L.P.) - Lessee Future Minimum Payments - (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)communitylease	Dec. 31, 2019USD ($)
Lessee operating leases
Number of communities subject to ground leases | community	6
Number of leases | lease	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 203,410	$ 204,225
Weighted average remaining lease term	44 years 6 months
Weighted average discount rate	5.00%
Number of real estate properties | community	150
Future minimum lease payments
Operating lease liabilities	$ 197,829	198,558
Ground Leases
Future minimum lease payments
2020	9,330
2021	12,442
2022	12,442
2023	12,442
2024	12,442
Thereafter	455,221
Total future minimum lease payments (undiscounted)	514,319
Difference between future undiscounted cash flows and discounted cash flows	(316,490)
Operating lease liabilities	$ 197,829
United Dominion Realty L.P.
Lessee operating leases
Number of communities subject to ground leases | community	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 204,723	205,668
Weighted average remaining lease term	44 years 6 months
Weighted average discount rate	5.00%
Number of real estate properties | community	52
Future minimum lease payments
2020	$ 9,438
2021	12,589
2022	12,592
2023	12,595
2024	12,598
Thereafter	456,016
Total future minimum lease payments (undiscounted)	515,828
Difference between future undiscounted cash flows and discounted cash flows	(316,679)
Operating lease liabilities	199,149	$ 200,001
United Dominion Realty L.P. | Ground Leases
Future minimum lease payments
2020	9,330
2021	12,442
2022	12,442
2023	12,442
2024	12,442
Thereafter	455,221
Total future minimum lease payments (undiscounted)	514,319
Difference between future undiscounted cash flows and discounted cash flows	(316,490)
Operating lease liabilities	197,829
United Dominion Realty L.P. | Equipment Leases
Future minimum lease payments
2020	108
2021	147
2022	150
2023	153
2024	156
Thereafter	795
Total future minimum lease payments (undiscounted)	1,509
Difference between future undiscounted cash flows and discounted cash flows	(189)
Operating lease liabilities	$ 1,320

LEASES (UNITED DOMINION REALT_4

LEASES (UNITED DOMINION REALTY, L.P.) - Lessee Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee operating leases
Contractual ground lease expense	$ 100	$ 100
Variable ground lease expense	100	200
Operating lease right-of-use asset amortization	800	200
Operating lease liabilities amortization	700	100
Ground Leases
Lessee operating leases
Contractual ground lease expense	3,170	2,159
Variable ground lease expense	43	139
United Dominion Realty L.P.
Lessee operating leases
Contractual ground lease expense	100	100
Total lease expense	3,249	2,279
Operating lease right-of-use asset amortization	900
Operating lease liabilities amortization	900
United Dominion Realty L.P. | Ground Leases
Lessee operating leases
Contractual ground lease expense	3,170	2,140
Variable ground lease expense	43	139
Total lease expense	3,213	$ 2,279
United Dominion Realty L.P. | Equipment Leases
Lessee operating leases
Total lease expense	$ 36

LEASES (UNITED DOMINION REALT_5

LEASES (UNITED DOMINION REALTY, L.P.) - Lessor (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2020	Mar. 31, 2019
Future minimum lease payments
Variable lease expense		$ 100	$ 200
Apartment Homes
Lessor leases
Percentage of lease revenue		98.40%
Apartment Homes | Maximum
Lessor leases
Lease terms		12 months
Retail and Commercial Spaces
Lessor leases
Percentage of lease revenue		1.60%
Future minimum lease payments
2020		$ 16,849
2021		22,487
2022		20,781
2023		19,317
2024		17,594
Thereafter		81,662
Total future minimum payments		$ 178,690
Retail and Commercial Spaces | Minimum
Lessor leases
Lease terms		5 years
Retail and Commercial Spaces | Maximum
Lessor leases
Lease terms		15 years
United Dominion Realty L.P. | Minimum
Lessor leases
Lease terms	5 years
United Dominion Realty L.P. | Maximum
Lessor leases
Lease terms	15 years
United Dominion Realty L.P. | Apartment Homes
Lessor leases
Percentage of lease revenue		98.40%
United Dominion Realty L.P. | Apartment Homes | Maximum
Lessor leases
Lease terms		12 months
United Dominion Realty L.P. | Retail and Commercial Spaces
Lessor leases
Percentage of lease revenue	1.60%
Future minimum lease payments
2020		$ 5,678
2021		7,311
2022		6,688
2023		6,361
2024		5,693
Thereafter		14,807
Total future minimum payments		46,538
United Dominion Realty L.P. | Retail and Commercial Spaces | Maximum
Future minimum lease payments
Variable lease expense		$ 100	$ 100

DEBT, NET (UNITED DOMINION RE_3

DEBT, NET (UNITED DOMINION REALTY, L.P.) - Summary (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)community	Dec. 31, 2019USD ($)
Fixed and variable rate debt
Weighted Average Interest Rate	3.28%
Long-term Debt	$ 4,885,138	$ 4,707,524
Weighted Average
Fixed and variable rate debt
Years to maturity	7 years 1 month 6 days
Fixed Rate Debt | Mortgages Note Payable
Fixed and variable rate debt
Principal outstanding	$ 883,249	884,869
Weighted Average Interest Rate	3.61%
Communities Encumbered (in communities) | community	15
Fixed Rate Debt | Mortgages Note Payable | Weighted Average
Fixed and variable rate debt
Years to maturity	5 years 10 months 24 days
Fixed Rate Debt | Credit facilities
Fixed and variable rate debt
Principal outstanding	$ 203,429	204,590
Weighted Average Interest Rate	4.90%
Communities Encumbered (in communities) | community	4
Fixed Rate Debt | Credit facilities | Weighted Average
Fixed and variable rate debt
Years to maturity	2 years 9 months 18 days
Variable Rate Debt | Tax-exempt secured notes payable
Fixed and variable rate debt
Principal outstanding	$ 27,000	27,000
Weighted Average Interest Rate	1.91%
Communities Encumbered (in communities) | community	1
Variable Rate Debt | Tax-exempt secured notes payable | Weighted Average
Fixed and variable rate debt
Years to maturity	12 years
United Dominion Realty L.P.
Fixed and variable rate debt
Weighted Average Interest Rate	2.83%
Communities Encumbered (in communities) | community	2
Long-term Debt	$ 99,082	99,071
United Dominion Realty L.P. | Weighted Average
Fixed and variable rate debt
Years to maturity	10 years 4 months 24 days
United Dominion Realty L.P. | Mortgages Note Payable
Fixed and variable rate debt
Principal outstanding	$ 72,500
Interest rate	3.10%
United Dominion Realty L.P. | Fixed Rate Debt
Fixed and variable rate debt
Weighted Average Interest Rate	3.10%
Communities Encumbered (in communities) | community	1
Long-term Debt	$ 72,144	72,135
United Dominion Realty L.P. | Fixed Rate Debt | Weighted Average
Fixed and variable rate debt
Years to maturity	9 years 9 months 18 days
United Dominion Realty L.P. | Fixed Rate Debt | Mortgages Note Payable
Fixed and variable rate debt
Principal outstanding	$ 72,500	72,500
Weighted Average Interest Rate	3.10%
Communities Encumbered (in communities) | community	1
Deferred finance costs, net	$ (356)	(365)
United Dominion Realty L.P. | Fixed Rate Debt | Mortgages Note Payable | Weighted Average
Fixed and variable rate debt
Years to maturity	9 years 9 months 18 days
United Dominion Realty L.P. | Variable Rate Debt
Fixed and variable rate debt
Weighted Average Interest Rate	1.91%
Communities Encumbered (in communities) | community	1
Deferred finance costs, net	$ (62)	(64)
Long-term Debt	$ 26,938	26,936
United Dominion Realty L.P. | Variable Rate Debt | Weighted Average
Fixed and variable rate debt
Years to maturity	12 years
United Dominion Realty L.P. | Variable Rate Debt | Tax-exempt secured notes payable
Fixed and variable rate debt
Principal outstanding	$ 27,000	$ 27,000
Weighted Average Interest Rate	1.91%
Communities Encumbered (in communities) | community	1
United Dominion Realty L.P. | Variable Rate Debt | Tax-exempt secured notes payable | Weighted Average
Fixed and variable rate debt
Years to maturity	12 years
Credit facilities
Fixed and variable rate debt
Principal outstanding	$ 203,400
Credit facilities | Fixed Rate Debt
Fixed and variable rate debt
Weighted Average Interest Rate	4.90%

DEBT, NET (UNITED DOMINION RE_4

DEBT, NET (UNITED DOMINION REALTY, L.P.) - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2020	Mar. 31, 2020	Feb. 29, 2020	Dec. 31, 2019	Oct. 31, 2019	Jul. 31, 2019
Fixed and variable rate debt
Long-term commercial paper		$ 500,000
Borrowings outstanding		2,500		$ 2,900
Repayment of debt	$ 215,000
Unsecured Commercial Bank Credit Facility
Fixed and variable rate debt
Repayment of debt		215,000
Commercial Paper
Fixed and variable rate debt
Commercial paper program		$ 215,000		$ 300,000
Interest rate at the end of the period		1.60%		2.00%
Unsecured Revolving Credit Facility
Fixed and variable rate debt
Borrowings outstanding		$ 50,000		$ 0
3.20% Medium-Term Notes due January 2030
Fixed and variable rate debt
Guarantor borrowing capacity		600,000
Interest rate			3.20%		3.20%	3.20%
Medium-Term Notes Due August 2031
Fixed and variable rate debt
Guarantor borrowing capacity		400,000
3.10% senior unsecured notes due 2034
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | Financial Guarantee
Fixed and variable rate debt
Guarantor borrowing capacity		1,100,000
United Dominion Realty L.P. | Unsecured Commercial Bank Credit Facility
Fixed and variable rate debt
Long-term commercial paper		$ 500,000
United Dominion Realty L.P. | Mortgages Note Payable
Fixed and variable rate debt
Interest rate		3.10%
United Dominion Realty L.P. | Mortgages Note Payable | Variable Rate Debt | Operating Partnership
Fixed and variable rate debt
Interest rate at the end of the period		1.91%
United Dominion Realty L.P. | Unsecured Commercial Paper
Fixed and variable rate debt
Borrowings outstanding		$ 215,000		$ 300,000
United Dominion Realty L.P. | 3.70% Term Notes Due October 2020
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | Term Loan due September 2023
Fixed and variable rate debt
Guarantor borrowing capacity		350,000
United Dominion Realty L.P. | 3.75% Medium-Term Notes Due July 2024
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | 4.00% Medium-Term Note due October 2025
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | 2.95% Medium-Term Note due September 2026
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | 3.50 Medium-Term Note due July 2027
Fixed and variable rate debt
Guarantor borrowing capacity		300,000
United Dominion Realty L.P. | Medium-Term note due January 2029
Fixed and variable rate debt
Guarantor borrowing capacity		$ 300,000

RELATED PARTY TRANSACTIONS (U_3

RELATED PARTY TRANSACTIONS (UNITED DOMINION REALTY, L.P.) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Related party transactions
Related party management fees	$ 4,900	$ 4,000
United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	3.28%
Notes payable due to the General Partner	$ 635,738		$ 637,233
Interest expense, related party	6,722	7,181
United Dominion Realty L.P. | UDR, Inc.
Related party transactions
General and administrative expenses allocated to the Operating Partnership by UDR	$ 3,600	$ 3,600
Note due August 2021 | United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	5.34%
Notes payable due to the General Partner	$ 5,500		5,500
Note due December 2023 | United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	5.18%
Notes payable due to the General Partner	$ 83,196		83,196
Note due April 2026 | United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	4.12%
Notes payable due to the General Partner	$ 184,638		184,638
Note due November 2028 | United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	4.69%
Notes payable due to the General Partner	$ 133,205		133,205
Note due December 2028 | United Dominion Realty L.P.
Related party transactions
Debt Instrument, Interest Rate Period End	3.28%
Notes payable due to the General Partner	$ 229,199		$ 230,694

FAIR VALUE OF DERIVATIVES AND_6

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (UNITED DOMINION REALTY, L.P.) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt instruments - fair value
Transfer between the levels	$ 0
Fair Value, Measurements, Recurring | Carrying Amount
Debt instruments - fair value
Total liabilities	4,913,746	$ 4,731,595
Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Total liabilities	4,907,068	4,853,337
Level 2 | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Total liabilities	3,075	142
Level 3 | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Total liabilities	4,903,993	4,853,195
United Dominion Realty L.P. | Fair Value, Measurements, Recurring | Carrying Amount
Debt instruments - fair value
Total liabilities	99,500	99,500
United Dominion Realty L.P. | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Total liabilities	100,663	98,976
United Dominion Realty L.P. | Mortgages Note Payable | Fair Value, Measurements, Recurring | Carrying Amount
Debt instruments - fair value
Fair value		72,500
United Dominion Realty L.P. | Mortgages Note Payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value		71,976
United Dominion Realty L.P. | Level 3 | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Total liabilities	100,663	98,976
United Dominion Realty L.P. | Level 3 | Mortgages Note Payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value		71,976
Fixed Rate Debt | United Dominion Realty L.P. | Mortgages Note Payable | Fair Value, Measurements, Recurring | Carrying Amount
Debt instruments - fair value
Fair value	72,500
Fixed Rate Debt | United Dominion Realty L.P. | Mortgages Note Payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value	73,663
Fixed Rate Debt | United Dominion Realty L.P. | Level 3 | Mortgages Note Payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value	73,663
Variable Rate Debt | United Dominion Realty L.P. | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring | Carrying Amount
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt | United Dominion Realty L.P. | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt | United Dominion Realty L.P. | Level 3 | Tax-exempt secured notes payable | Fair Value, Measurements, Recurring | Fair Value
Debt instruments - fair value
Fair value	$ 27,000	$ 27,000

DERIVATIVES AND HEDGING ACTI_10

DERIVATIVES AND HEDGING ACTIVITY (UNITED DOMINION REALTY, L.P.) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)instrument	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Derivatives
Estimated additional accumulated other comprehensive Income/(Loss) transferred to interest expense	$ 4,600
Interest rate caps | Not Designated as Hedging Instrument
Outstanding interest rate derivatives not designated as hedging instrument
Number instruments | instrument	1
Notional	$ 19,880
United Dominion Realty L.P.
Derivatives
Derivatives	0		$ 0
United Dominion Realty L.P. | Interest rate contracts
Derivatives
Gain/(Loss) recognized in Interest Income and Other Income/(Expense), net	$ 0	$ 0
United Dominion Realty L.P. | Interest rate caps | Not Designated as Hedging Instrument
Outstanding interest rate derivatives not designated as hedging instrument
Number instruments | instrument	1
Notional	$ 19,880
Other income/(expense) | Interest rate contracts
Derivatives
Gain/(Loss) recognized in Interest Income and Other Income/(Expense), net	0	0
Other income/(expense) | United Dominion Realty L.P. | Interest rate contracts
Derivatives
Gain/(Loss) recognized in Interest Income and Other Income/(Expense), net	$ 0	$ 0

CAPITAL STRUCTURE (UNITED DOM_3

CAPITAL STRUCTURE (UNITED DOMINION REALTY, L.P.) - Units Rollforward (Details)	3 Months Ended
	Mar. 31, 2020shares
Capital structure
Balance	184,064,000
Vesting of LTIP Units	772,000
Balance	184,836,000
UDR, Inc.
Capital structure
Balance	176,100,000
Balance	176,100,000
Non-affiliated Partners
Capital structure
Balance	8.6
Class A Limited Partner | UDR, Inc.
Capital structure
Balance	100,000
Balance	100,000
Non-affiliated Partners | Class A Limited Partner
Capital structure
Balance	1,752,000
Balance	1,752,000
Limited Partner
Capital structure
Balance	6,094,000
Vesting of LTIP Units	772,000
Balance	6,866,000
Limited Partner | UDR, Inc.
Capital structure
Balance	175,986,000
Balance	175,986,000
Class A Limited Partner | UDR, Inc.
Capital structure
Balance	121,000
Balance	121,000
General Partner | UDR, Inc.
Capital structure
Balance	111,000
Balance	111,000

CAPITAL STRUCTURE (UNITED DOM_4

CAPITAL STRUCTURE (UNITED DOMINION REALTY, L.P.) - Ownership Interests (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)class$ / sharesshares	Dec. 31, 2019USD ($)shares
Capital structure
Limited partnership units owned	184,836,000	184,064,000
Redeemable noncontrolling interests in the Operating Partnership | $	$ 819,133	$ 1,018,665
Number of classes of LTIP Units | class	2
United Dominion Realty L.P.
Capital structure
General Partnership units outstanding	100,000
Limited partnership units owned	176.2
United Dominion Realty L.P.
Capital structure
General Partnership units outstanding	110,883	110,883
Limited partnership units owned	184,724,677	183,952,659
Required period to be outstanding before unit is redeemable (in years)	1 year
Redeemable noncontrolling interests in the Operating Partnership | $	$ 314,900	$ 366,400
UDR, Inc.
Capital structure
Limited partnership units owned	176,100,000	176,100,000
Percentage of units	95.30%	95.70%
UDR, Inc. | United Dominion Realty L.P.
Capital structure
General Partnership units outstanding	176.2
Percentage of units		95.70%
Non-affiliated Partners
Capital structure
Limited partnership units owned	8.6
Percentage of units	4.70%
Non-affiliated Partners | United Dominion Realty L.P.
Capital structure
Limited partnership units owned	8.6
Percentage of units	4.70%	4.30%
Class A Limited Partner
Capital structure
Cumulative, annual, non-compounded preferred return on Class A Partnership units	8.00%
Value of Class A Partnership units (in dollars per share) | $ / shares	$ 16.61
Class A Limited Partner | United Dominion Realty L.P.
Capital structure
Limited partnership units owned	1,900,000	1,900,000
Class A Limited Partner | UDR, Inc.
Capital structure
Limited partnership units owned	100,000	100,000
Non-affiliated Partners | United Dominion Realty L.P.
Capital structure
Limited partnership units owned	8,600,000	7,900,000
Percentage of units	4.70%	4.30%
Non-affiliated Partners | Class A Limited Partner
Capital structure
Limited partnership units owned	1,752,000	1,752,000
LTIP Units One
Capital structure
Vesting period	4 years
Minimum | LTIP Units
Capital structure
Vesting period	1 year
Period of time LTIP units have been outstanding	2 years
Minimum | Employee Director | LTIP Units Two
Capital structure
Vesting period	1 year
Maximum | LTIP Units
Capital structure
Vesting period	3 years
Maximum | Employee Director | LTIP Units Two
Capital structure
Vesting period	3 years

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES (UNITED DOMINION REALTY, L.P.) Commitments and Contingencies (Details) $ in Thousands	Mar. 31, 2020USD ($)community
Commitments
Number of communities owned (in communities) | community	150
Cost Incurred to Date	$ 161,997
UDR's Remaining Commitment	$ 229,062
United Dominion Realty L.P.
Commitments
Number of communities owned (in communities) | community	52
Real estate communities - redevelopment | United Dominion Realty L.P.
Commitments
Number of communities owned (in communities) | community	1
Cost Incurred to Date	$ 9,150
UDR's Remaining Commitment	$ 5,850

REPORTABLE SEGMENTS (UNITED D_3

REPORTABLE SEGMENTS (UNITED DOMINION REALTY, L.P.) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)segment	Mar. 31, 2020USD ($)item	Mar. 31, 2020USD ($)	Mar. 31, 2020USD ($)home	Mar. 31, 2019USD ($)item	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segments
Same store communities			37,910		37,910	37,910
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Rental income				$ 320,093		$ 267,922
Reconciling items:
Property management				(9,203)		(7,703)
Other operating expenses				(4,966)		(5,646)
Real estate depreciation and amortization				(155,476)		(112,468)
General and administrative				(14,978)		(12,467)
Casualty-related (charges)/recoveries, net				(1,251)
Income/(loss) from unconsolidated entities				3,367		49
Interest expense				(39,317)		(33,542)
Net (income)/loss attributable to noncontrolling interests				(6)		(42)
Net income/(loss) attributable to OP unitholders				5,221		24,503
Reportable apartment home segment assets:
Total segment assets	$ 12,817,998	$ 12,817,998	$ 12,817,998	12,817,998	$ 12,817,998		$ 12,602,101
Accumulated depreciation	(4,272,471)	(4,272,471)	(4,272,471)	(4,272,471)	(4,272,471)		(4,131,353)
Total real estate owned, net of accumulated depreciation	8,545,527	8,545,527	8,545,527	8,545,527	8,545,527		8,470,748
Total segment asset - net book value	8,545,527	8,545,527	8,545,527	8,545,527	8,545,527		8,470,748
Reconciling items:
Cash and cash equivalents	980	980	980	980	980	1,043	8,106	$ 185,216
Restricted cash	21,949	21,949	21,949	21,949	21,949	23,111	25,185	23,675
Investment in unconsolidated entities	588,395	588,395	588,395	588,395	588,395		588,262
Operating lease right-of-use assets	203,410	203,410	203,410	203,410	203,410		204,225
Other assets	179,301	179,301	179,301	179,301	179,301		186,296
Total assets	$ 9,691,105	$ 9,691,105	9,691,105	9,691,105	9,691,105		9,636,472
Reportable Segments
Number of reportable segments | segment		2
Condition for Community considered to have stabilized occupancy	90%
Time to maintain percent occupancy to be considered a community	3 months
Practical expedient, single lease component	true
Same Store Communities West Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				102,616		98,633
Other revenue				2,774		3,076
Rental income				105,390		101,709
Reportable apartment home segment NOI				79,823		76,984
Reportable apartment home segment assets:
Total segment assets	$ 3,704,480	$ 3,704,480	3,704,480	3,704,480	3,704,480		3,696,544
Same Store Communities Mid-Atlantic Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				56,085		54,300
Other revenue				1,573		2,002
Rental income				57,658		56,302
Reportable apartment home segment NOI				40,377		39,179
Reportable apartment home segment assets:
Total segment assets	2,356,688	2,356,688	2,356,688	2,356,688	2,356,688		2,350,341
Same Store Communities Northeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				30,942		30,193
Other revenue				501		629
Rental income				31,443		30,822
Reportable apartment home segment NOI				20,614		20,977
Reportable apartment home segment assets:
Total segment assets	1,501,767	1,501,767	1,501,767	1,501,767	1,501,767		1,500,597
Same Store Communities Southeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				30,677		29,531
Other revenue				1,429		1,790
Rental income				32,106		31,321
Reportable apartment home segment NOI				22,617		22,010
Reportable apartment home segment assets:
Total segment assets	810,984	810,984	810,984	810,984	810,984		806,830
Same Store Communities Southwest Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				16,626		16,077
Other revenue				590		763
Rental income				17,216		16,840
Reportable apartment home segment NOI				11,056		10,328
Reportable apartment home segment assets:
Total segment assets	603,082	603,082	603,082	603,082	603,082		600,350
Non-Mature communities/Other
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				74,676		30,169
Other revenue				1,604		759
Rental income				76,280		30,928
Reportable apartment home segment NOI				50,978		20,205
Reportable apartment home segment assets:
Total segment assets	3,840,997	3,840,997	$ 3,840,997	3,840,997	$ 3,840,997		3,647,439
Total Communities
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				311,622		258,903
Other revenue				8,471		9,019
Rental income				320,093		267,922
Reportable apartment home segment NOI				225,465		189,683
United Dominion Realty L.P.
Segments
Same store communities			15,941		15,941
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Rental income				112,165		108,334
Reconciling items:
Property management				(3,225)		(2,979)
Other operating expenses				(3,859)		(2,400)
Real estate depreciation and amortization				(35,300)		(34,654)
General and administrative				(5,308)		(4,661)
Casualty-related (charges)/recoveries, net				2
Income/(loss) from unconsolidated entities				(1,761)		(2,740)
Interest expense				(7,464)		(7,371)
Net (income)/loss attributable to noncontrolling interests				(522)		(388)
Net income/(loss) attributable to OP unitholders				24,118		23,946
Reportable apartment home segment assets:
Total segment assets	3,886,613	3,886,613	$ 3,886,613	3,886,613	$ 3,886,613		3,875,160
Accumulated depreciation	(1,831,814)	(1,831,814)	(1,831,814)	(1,831,814)	(1,831,814)		(1,796,568)
Total real estate owned, net of accumulated depreciation	2,054,799	2,054,799	2,054,799	2,054,799	2,054,799		2,078,592
Total segment asset - net book value	2,054,799	2,054,799	2,054,799	2,054,799	2,054,799		2,078,592
Reconciling items:
Cash and cash equivalents	40	40	40	40	40	59	24	125
Restricted cash	14,121	14,121	14,121	14,121	14,121	14,010	13,998	$ 13,563
Investment in unconsolidated entities	69,617	69,617	69,617	69,617	69,617		76,222
Operating lease right-of-use assets	204,723	204,723	204,723	204,723	204,723		205,668
Other assets	24,042	24,042	24,042	24,042	24,042		24,241
Total assets	$ 2,367,342	$ 2,367,342	2,367,342	2,367,342	2,367,342		2,398,745
Reportable Segments
Number of reportable segments | segment		2
Condition for Community considered to have stabilized occupancy	90%
Time to maintain percent occupancy to be considered a community	3 months
Practical expedient, single lease component	true
United Dominion Realty L.P. | Same Store Communities West Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				63,242		60,782
Other revenue				1,779		1,995
Rental income				65,021		62,777
Reportable apartment home segment NOI				49,493		47,797
Reportable apartment home segment assets:
Total segment assets	$ 2,017,542	$ 2,017,542	2,017,542	2,017,542	2,017,542		2,011,495
United Dominion Realty L.P. | Same Store Communities Mid-Atlantic Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				15,164		14,810
Other revenue				431		535
Rental income				15,595		15,345
Reportable apartment home segment NOI				10,796		10,524
Reportable apartment home segment assets:
Total segment assets	671,170	671,170	671,170	671,170	671,170		669,417
United Dominion Realty L.P. | Same Store Communities Northeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				8,229		7,972
Other revenue				101		166
Rental income				8,330		8,138
Reportable apartment home segment NOI				5,909		6,205
Reportable apartment home segment assets:
Total segment assets	408,954	408,954	408,954	408,954	408,954		408,703
United Dominion Realty L.P. | Same Store Communities Southeast Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				12,987		12,462
Other revenue				644		775
Rental income				13,631		13,237
Reportable apartment home segment NOI				9,550		9,257
Reportable apartment home segment assets:
Total segment assets	354,058	354,058	354,058	354,058	354,058		352,790
United Dominion Realty L.P. | Same Store Communities Southwest Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				1,830		1,924
Other revenue				71		31
Rental income				1,901		1,955
Reportable apartment home segment NOI				1,391		1,337
Reportable apartment home segment assets:
Total segment assets	144,640	144,640	144,640	144,640	144,640		144,210
United Dominion Realty L.P. | Non-Mature communities/Other
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				7,550		6,726
Other revenue				137		156
Rental income				7,687		6,882
Reportable apartment home segment NOI				4,416		4,019
Reportable apartment home segment assets:
Total segment assets	$ 290,249	$ 290,249	$ 290,249	290,249	$ 290,249		$ 288,545
United Dominion Realty L.P. | Total Communities
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue				109,002		104,676
Other revenue				3,163		3,658
Rental income				112,165		108,334
Reportable apartment home segment NOI				$ 81,555		$ 79,139