UDR (UDR) 10-Q 27 Oct 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Oct. 24, 2023
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
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, par value $0.01
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		328,928,134
Entity Central Index Key	0000074208
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Real estate owned:
Real estate held for investment	$ 15,779,481	$ 15,365,928
Less: accumulated depreciation	(6,117,312)	(5,762,205)
Real estate held for investment, net	9,662,169	9,603,723
Real estate under development (net of accumulated depreciation of $0 and $296, respectively)	139,143	189,809
Real estate held for disposition (net of accumulated depreciation of $0 and $0, respectively)		14,039
Total real estate owned, net of accumulated depreciation	9,801,312	9,807,571
Cash and cash equivalents	1,624	1,193
Restricted cash	30,831	29,001
Notes receivable, net	209,297	54,707
Investment in and advances to unconsolidated joint ventures, net	963,927	754,446
Operating lease right-of-use assets	191,499	194,081
Other assets	221,572	197,471
Total assets	11,420,062	11,038,470
Liabilities:
Secured debt, net	1,238,240	1,052,281
Unsecured debt, net	4,514,582	4,435,022
Operating lease liabilities	186,701	189,238
Real estate taxes payable	68,900	37,681
Accrued interest payable	27,071	46,671
Security deposits and prepaid rent	50,571	51,999
Distributions payable	149,615	134,213
Accounts payable, accrued expenses, and other liabilities	125,979	153,220
Total liabilities	6,361,659	6,100,325
Commitments and contingencies (Note 13)
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	907,269	839,850
Equity:
Common stock, $0.01 par value; 450,000,000 shares authorized at September 30, 2023 and December 31, 2022: 328,904,161 and 328,993,088 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	3,289	3,290
Additional paid-in capital	7,487,515	7,493,423
Distributions in excess of net income	(3,392,855)	(3,451,587)
Accumulated other comprehensive income/(loss), net	8,360	8,344
Total stockholders' equity	4,150,924	4,098,085
Noncontrolling interests	210	210
Total equity	4,151,134	4,098,295
Total liabilities and equity	11,420,062	11,038,470
8.00% Series E Cumulative Convertible Preferred Stock
Equity:
Preferred stock, no par value; 50,000,000 shares authorized at September 30, 2023 and December 31, 2022:	44,614	44,614
Series F
Equity:
Preferred stock, no par value; 50,000,000 shares authorized at September 30, 2023 and December 31, 2022:	$ 1	$ 1

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Real estate owned:
Real estate under development accumulated depreciation	$ 0	$ 296
Real estate held for disposition accumulated depreciation	$ 0	$ 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	450,000,000	450,000,000
Common stock, shares issued	328,904,161	328,993,088
Common stock, shares outstanding	328,904,161	328,993,088
8.00% Series E Cumulative Convertible Preferred Stock
Equity:
Preferred stock, dividend rate percentage	8%	8%
Preferred stock, shares issued	2,686,308	2,686,308
Preferred stock, shares outstanding	2,686,308	2,686,308
Series F
Equity:
Preferred stock, shares issued	11,891,530	12,100,514
Preferred stock, shares outstanding	11,891,530	12,100,514

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
REVENUES:
Rental income	$ 408,359	$ 390,023	$ 1,209,764	$ 1,113,952
Joint venture management and other fees	$ 1,772	$ 1,274	$ 4,464	$ 3,778
Type of revenue	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
Total revenues	$ 410,131	$ 391,297	$ 1,214,228	$ 1,117,730
OPERATING EXPENSES:
Property operating and maintenance	71,599	66,769	205,294	185,658
Real estate taxes and insurance	58,104	58,236	173,590	164,788
Property management	13,271	12,675	39,317	36,203
Other operating expenses	4,611	3,746	11,902	13,485
Real estate depreciation and amortization	167,551	166,781	505,776	497,987
General and administrative	15,159	15,840	49,091	47,333
Casualty-related charges/(recoveries), net	(1,928)	901	3,362	1,210
Other depreciation and amortization	3,692	3,430	11,022	9,521
Total operating expenses	332,059	328,378	999,354	956,185
Gain/(loss) on sale of real estate owned	0	0	325,885	0
Operating income	78,072	62,919	540,759	161,545
Income/(loss) from unconsolidated entities	5,508	10,003	24,912	4,186
Interest expense	(44,664)	(39,905)	(133,519)	(112,653)
Interest income and other income/(expense), net	(3,069)	(7,495)	8,388	(6,934)
Income/(loss) before income taxes	35,847	25,522	440,540	46,144
Tax (provision)/benefit, net	(428)	(377)	(2,013)	(1,032)
Net income/(loss)	35,419	25,145	438,527	45,112
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(2,554)	(1,533)	(27,137)	(2,684)
Net (income)/loss attributable to noncontrolling interests	(7)	(7)	(23)	(34)
Net income/(loss) attributable to UDR, Inc.	32,858	23,605	411,367	42,394
Distributions to preferred stockholders - Series E (Convertible)	(1,221)	(1,106)	(3,626)	(3,307)
Net income/(loss) attributable to common stockholders	$ 31,637	$ 22,499	$ 407,741	$ 39,087
Income/(loss) per weighted average common share - basic	$ 0.10	$ 0.07	$ 1.24	$ 0.12
Income/(loss) per weighted average common share - diluted	$ 0.10	$ 0.07	$ 1.24	$ 0.12
Weighted average number of common shares outstanding - basic	328,760	324,701	328,835	320,378
Weighted average number of common shares outstanding - diluted	329,201	325,686	329,283	321,629

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS)
Net income/(loss)	$ 35,419	$ 25,145	$ 438,527	$ 45,112
Other comprehensive income/(loss), including portion attributable to noncontrolling interests:
Unrealized holding gain/(loss)	1,314	5,048	5,336	13,988
(Gain)/loss reclassified into earnings from other comprehensive income/(loss)	(2,110)	(313)	(5,332)	(28)
Other comprehensive income/(loss), including portion attributable to noncontrolling interests	(796)	4,735	4	13,960
Comprehensive income/(loss)	34,623	29,880	438,531	59,072
Comprehensive (income)/loss attributable to noncontrolling interests	(2,521)	(1,840)	(27,148)	(3,638)
Comprehensive income/(loss) attributable to UDR, Inc.	$ 32,102	$ 28,040	$ 411,383	$ 55,434

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)	Noncontrolling Interest	Total
Beginning Balance at Dec. 31, 2021	$ 44,765	$ 3,181	$ 6,884,269	$ (3,485,080)	$ (4,261)	$ 31,430	$ 3,474,304
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				42,394			42,394
Long Term Incentive Plan Unit grants/(vestings), net						(31,220)	(31,220)
Other comprehensive income/(loss)					13,040		13,040
Issuance/(forfeiture) of common and restricted shares, net		1	2,857				2,858
Issuance of common shares through public offering, net		83	449,862				449,945
Conversion of Series E Cumulative Convertible shares	(150)	1	149
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership		2	10,136				10,138
Common stock distributions declared				(368,549)			(368,549)
Repurchase of common shares		(4)	(15,146)				(15,150)
Preferred stock distributions declared-Series E				(3,307)			(3,307)
Adjustment to reflect redemption value of redeemable noncontrolling interests				376,515			376,515
Ending Balance at Sep. 30, 2022	44,615	3,264	7,332,127	(3,438,027)	8,779	210	3,950,968
Beginning Balance at Jun. 30, 2022	44,765	3,249	7,243,825	(3,426,760)	4,345	210	3,869,634
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				23,605			23,605
Other comprehensive income/(loss)					4,434		4,434
Issuance/(forfeiture) of common and restricted shares, net			2,082				2,082
Issuance of common shares through public offering, net		18	99,659				99,677
Conversion of Series E Cumulative Convertible shares	(150)	1	149
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership			1,558				1,558
Common stock distributions declared				(124,018)			(124,018)
Repurchase of common shares		(4)	(15,146)				(15,150)
Preferred stock distributions declared-Series E				(1,106)			(1,106)
Adjustment to reflect redemption value of redeemable noncontrolling interests				90,252			90,252
Ending Balance at Sep. 30, 2022	44,615	3,264	7,332,127	(3,438,027)	8,779	210	3,950,968
Beginning Balance at Dec. 31, 2022	44,615	3,290	7,493,423	(3,451,587)	8,344	210	4,098,295
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				411,367			411,367
Other comprehensive income/(loss)					16		16
Issuance/(forfeiture) of common and restricted shares, net		2	4,808				4,810
Issuance of common shares through public offering, net			(473)				(473)
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership		3	14,760				14,763
Common stock distributions declared				(414,808)			(414,808)
Repurchase of common shares		(6)	(25,003)				(25,009)
Preferred stock distributions declared-Series E				(3,626)			(3,626)
Adjustment to reflect redemption value of redeemable noncontrolling interests				65,799			65,799
Ending Balance at Sep. 30, 2023	44,615	3,289	7,487,515	(3,392,855)	8,360	210	4,151,134
Beginning Balance at Jun. 30, 2023	44,615	3,295	7,508,616	(3,445,679)	9,116	210	4,120,173
Consolidated Statements of Changes in Equity
Net income/(loss) attributable to UDR, Inc.				32,858			32,858
Other comprehensive income/(loss)					(756)		(756)
Issuance/(forfeiture) of common and restricted shares, net			1,842				1,842
Adjustment for conversion of noncontrolling interest of unitholders in the Operating Partnership and DownREIT Partnership			2,060				2,060
Common stock distributions declared				(138,111)			(138,111)
Repurchase of common shares		(6)	(25,003)				(25,009)
Preferred stock distributions declared-Series E				(1,221)			(1,221)
Adjustment to reflect redemption value of redeemable noncontrolling interests				159,298			159,298
Ending Balance at Sep. 30, 2023	$ 44,615	$ 3,289	$ 7,487,515	$ (3,392,855)	$ 8,360	$ 210	$ 4,151,134

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Common stock distributions declared per share	$ 0.42	$ 0.38	$ 1.26	$ 1.14
8.00% Series E Cumulative Convertible Preferred Stock
Preferred stock distributions declared	$ 0.4548	$ 0.4114	$ 1.3644	$ 1.2342

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities
Net income/(loss)	$ 438,527	$ 45,112
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:
Depreciation and amortization	516,798	507,508
(Gain)/loss on sale of real estate owned	(325,885)	0
(Income)/loss from unconsolidated entities	(24,912)	(4,186)
Return on investment in unconsolidated joint ventures and partnerships	11,969	17,430
Amortization of share-based compensation	22,770	20,458
Other	10,516	22,898
Changes in operating assets and liabilities:
(Increase)/decrease in operating assets	(20,164)	(4,372)
Increase/(decrease) in operating liabilities	(16,026)	(2,210)
Net cash provided by/(used in) operating activities	613,593	602,638
Investing Activities
Acquisition of real estate assets	(17,848)	(341,149)
Proceeds from sales of real estate investments, net	247,935
Development of real estate assets	(120,644)	(159,455)
Capital expenditures and other major improvements - real estate assets	(220,341)	(144,673)
Capital expenditures - non-real estate assets	(14,081)	(12,631)
Investment in unconsolidated joint ventures and partnerships	(27,775)	(199,057)
Distributions received from unconsolidated joint ventures and partnerships	9,315	77,838
Purchase deposits on pending acquisitions	(1,000)	1,000
Repayment/(issuance) of notes receivable, net	(71,786)	(60,532)
Net cash provided by/(used in) investing activities	(216,225)	(838,659)
Financing Activities
Payments on secured debt	(884)	(852)
Net proceeds/(repayment) of commercial paper	80,000	205,000
Net proceeds/(repayment) of revolving bank debt	(1,316)	11,636
Proceeds from the issuance of common shares through public offering, net	(473)	449,945
Repurchase of common shares	(25,009)	(15,150)
Distributions paid to redeemable noncontrolling interests	(25,869)	(25,673)
Distributions paid to preferred stockholders	(3,540)	(3,268)
Distributions paid to common stockholders	(401,686)	(359,864)
Other	(16,330)	(24,276)
Net cash provided by/(used in) financing activities	(395,107)	237,498
Net increase/(decrease) in cash, cash equivalents, and restricted cash	2,261	1,477
Cash, cash equivalents, and restricted cash, beginning of year	30,194	28,418
Cash, cash equivalents, and restricted cash, end of period	32,455	29,895
Supplemental Information:
Interest paid during the period, net of amounts capitalized	156,606	131,588
Operating cash flows from operating leases	9,377	9,377
Cash paid/(refunds received) for income taxes	1,914	1,012
Non-cash transactions:
Secured debt assumed upon acquisition of real estate assets	191,737
OP Units issued for real estate, net	141,359
Redeemable long-term and short-term incentive plan units	19,334	50,084
Development costs and capital expenditures incurred, but not yet paid	42,760	47,862
Conversion of Operating Partnership and DownREIT Partnership noncontrolling interests to common stock (357,813 shares and 172,755 shares, respectively)	14,763	10,138
Distribution of equity securities from unconsolidated real estate technology investments	7,749	16,329
Contribution of operating properties to unconsolidated joint venture	258,056
Transfer of preferred equity investment to note receivable	73,453
Dividends declared, but not yet paid	$ 149,615	$ 133,341

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS - CASH RECONCILIATION - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
The following reconciles cash, cash equivalents, and restricted cash to amounts as shown above:
Cash and cash equivalents	$ 1,624	$ 1,193	$ 1,532	$ 967
Restricted cash	30,831	29,001	28,363	27,451
Total cash, cash equivalents, and restricted cash as shown above	$ 32,455	$ 30,194	$ 29,895	$ 28,418

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Non-cash transactions:
Conversion of OP Units into common shares (in shares)	357,813	172,755

BASIS OF PRESENTATION

BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2023
BASIS OF PRESENTATION
BASIS OF PRESENTATION	1. BASIS OF PRESENTATION Organization and Formation UDR, Inc. (“UDR,” the “Company,” “we,” or “our”) is a self-administered real estate investment trust, or REIT, that owns, operates, acquires, renovates, develops, redevelops, and manages apartment communities in targeted markets located in the United States. At September 30, 2023, our consolidated apartment portfolio consisted of 168 communities with a total of 55,597 apartment homes located in 21 markets. In addition, the Company has an ownership interest in 9,956 completed or to-be-completed apartment homes through unconsolidated joint ventures or partnerships, including 5,791 apartment homes owned by entities in which we hold preferred equity investments. Basis of Presentation The accompanying consolidated financial statements of UDR include its wholly-owned and/or controlled subsidiaries (see Note 4, Variable Interest Entities , Joint Ventures and Partnerships 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 September 30, 2023, there were 189.9 million units in the Operating Partnership (“OP Units”) outstanding, of which 176.4 million OP Units (including 0.1 million of general partnership units), or 92.9%, were owned by UDR and 13.5 million OP Units, or 7.1%, were owned by outside limited partners. As of September 30, 2023, there were 32.4 million units in the DownREIT Partnership (“DownREIT Units”) outstanding, of which 21.3 million, or 65.7%, were owned by UDR and its subsidiaries and 11.1 million, or 34.3%, 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 (the “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 September 30, 2023, and results of operations for the three and nine months ended September 30, 2023 and 2022, 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. 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, 2022 appearing in UDR’s Annual Report on Form 10-K, filed with the SEC on February 13, 2023. 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.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2023
SIGNIFICANT ACCOUNTING POLICIES
SIGNIFICANT ACCOUNTING POLICIES	2. SIGNIFICANT ACCOUNTING POLICIES 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 been transferred by the Company, 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 the Company’s 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 assets of the borrower that may include real estate 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 of the existing loans. 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 Accounting Standards Codification (“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 (a) ​ September 30, September 30, December 31, ​ ​ 2023 ​ 2023 ​ 2022 Notes due October 2024 (b) ​ 9.50 % $ 95,734 ​ $ — Note due December 2024 (c) ​ 12.00 % ​ 35,309 ​ ​ 30,377 Note due December 2026 (d) ​ 11.00 % ​ 51,309 ​ ​ 17,292 Note due December 2026 (e) ​ 11.00 % ​ 24,276 ​ ​ 5,813 Notes due June 2027 (f) ​ 18.00 % ​ 3,573 ​ ​ 1,500 Notes Receivable ​ ​ ​ ​ 210,201 ​ ​ 54,982 Allowance for credit losses ​ ​ ​ ​ (904) ​ ​ (275) Total notes receivable, net ​ $ 209,297 ​ $ 54,707 (a) Outstanding note amounts include any accrued and unpaid interest, as applicable. (b) In June 2023, the Company amended the agreement for a preferred equity investment in a joint venture that owns a 471 apartment home operating community located in Philadelphia, Pennsylvania, which resulted in the Company’s investment, inclusive of accrued preferred return, being classified as a note receivable. In connection with the amendment, the Company also advanced $20.0 million to the joint venture, which is also classified as a note receivable (collectively the “Notes”) and was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to January 2024. Furthermore, the contractual interest rate on the Notes increased to 9.5% (previously 8.5% ) in exchange for eliminating the Company’s upside participation in the joint venture. Interest payments accrue monthly and are due at maturity, but can be paid earlier. The Notes had an original scheduled maturity date in October 2023, with three one-year extension options. In September 2023, the developer extended the maturity date to October 2024. Commencing in October 2023, the contractual interest rate on the Notes increased to 10.5% when the developer exercised its option to extend the maturity date of the Notes. (See Note 5, Joint Ventures and Partnerships for further discussion.) (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $32.5 million, of which $30.9 million was funded as of September 30, 2023. During 2023, the terms of this secured note were amended to increase the aggregate commitment from $31.4 million to $32.5 million and to increase the interest rate from 10.0% to 12.0% . Interest payments are due monthly, with the exception of payments from June 2022 to December 2024, which are accrued and added to the principal balance and will be due at maturity of the note. The additional amount accrued and added to the principal balance was $4.4 million as of September 30, 2023. The note is secured by substantially all of the borrower’s assets and 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) December 2024. (d) The Company has a secured mezzanine loan with a third party developer of a 482 apartment home community located in Riverside, California, which is expected to be completed in 2025, with an aggregate commitment of $59.7 million (exclusive of accrued interest), of which $30.7 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (e) The Company has a secured mezzanine loan with a third party developer of a 237 apartment home community located in Menifee, California, which is expected to be completed in 2025, with an aggregate commitment of $24.4 million (exclusive of accrued interest), of which $17.5 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (f) The Company and a syndicate of lenders previously entered into a $16.0 million secured credit facility with an unaffiliated third party. During the nine months ended September 30, 2023, the secured credit facility was amended to provide a new term loan in the amount of $19.0 million, and increase the Company’s commitment from $1.5 million to $3.0 million (exclusive of accrued interest) , all of which has been funded. Interest payments will accrue and be due at maturity of the facility. The facility is secured by substantially all of the borrower’s assets and matures at the earliest of the following: (a) acceleration in the event of default; or (b) June 2027. The Company recognized $5.0 million and $1.0 million of interest income for the notes receivable described above during the three months ended September 30, 2023 and 2022, respectively, and $8.4 million and $2.4 million of interest income for the notes receivable described above during the nine months ended September 30, 2023 and 2022, 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 and nine months ended September 30, 2023 and 2022, 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 September 30, 2023 and December 31, 2022, UDR’s net deferred tax asset/(liability) was $(0.8) million and $(0.8) million, respectively, and are recorded in Accounts payable, accrued expenses and other liabilities 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 and evaluates its tax positions 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 September 30, 2023. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2020 through 2022 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 ​ From time to time 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 the entity’s 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 ​ Lease Receivables ​ During the three and nine months ended September 30, 2023 and 2022, the Company performed an analysis in accordance with the ASC 842, Leases, guidance to assess the collectibility of its operating lease receivables. This analysis included an assessment of collectibility of current and future rents and whether those lease payments were no longer probable of collection. In accordance with the leases guidance, if lease payments are no longer deemed to be probable over the life of the lease contract, we recognize revenue only when cash is received, and all existing contractual operating lease receivables and straight-line lease receivables are reserved. ​ As of September 30, 2023, the Company’s multifamily tenant lease receivables balance, net of its reserve, was approximately $9.2 million, including its share from unconsolidated joint ventures. The Company’s retail tenant lease receivables balance (exclusive of straight-line rent receivables), net of its reserve, was approximately $0.3 million, including its share from unconsolidated joint ventures, as of September 30, 2023.

REAL ESTATE OWNED

REAL ESTATE OWNED	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023, the Company owned and consolidated 168 communities in 13 states plus the District of Columbia totaling 55,597 apartment homes. The following table summarizes the carrying amounts for our real estate owned (at cost) as of September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Land ​ $ 2,558,608 ​ $ 2,539,499 Depreciable property — held and used: ​ ​ ​ Land improvements ​ 250,623 ​ 254,578 Building, improvements, and furniture, fixtures and equipment ​ 12,920,237 ​ 12,521,838 Real estate intangible assets ​ ​ 50,013 ​ ​ 50,013 Under development: ​ ​ Land and land improvements ​ 16,576 ​ 43,711 Building, improvements, and furniture, fixtures and equipment ​ 122,567 ​ 146,394 Real estate held for disposition: ​ ​ Building, improvements, and furniture, fixtures and equipment ​ — ​ 14,039 Real estate owned ​ 15,918,624 ​ 15,570,072 Accumulated depreciation (a) ​ (6,117,312) ​ (5,762,501) Real estate owned, net ​ $ 9,801,312 ​ $ 9,807,571 (a) Accumulated depreciation is inclusive of $16.2 million and $13.1 million of accumulated amortization related to real estate intangible assets as of September 30, 2023 and December 31, 2022, respectively. ​ Acquisitions In February 2023, the Company took Joint Ventures and Partnerships . ​ In August 2023, the Company acquired a portfolio of six operating communities totaling 1,753 apartment homes, which included four operating communities in Dallas, Texas and two operating communities in Austin, Texas, for a purchase price of $354.6 million. The Company acquired the portfolio with a combination of cash, the assumption of six mortgage loans and the issuance of 3.6 million OP Units to the seller valued at $141.4 million. The OP Units were valued based on the closing price per share of UDR’s common stock on the date of acquisition in accordance with GAAP. ​ Dispositions ​ In January 2023, the Company sold the retail component of a development community located in Washington D.C. for gross proceeds of approximately $14.4 million, resulting in an estimated gain of less than $0.1 million. ​ In June 2023, the Company contributed four wholly owned operating communities, totaling 1,328 apartment homes located in various markets, to a newly formed joint venture in exchange for a 51.0% interest in the venture. The contribution resulted in the Company no longer retaining a controlling interest in the communities, and the Company deconsolidated the operating communities. The Company received approximately $247.9 million in cash proceeds from our joint venture partner at formation. The transaction was accounted for as a partial sale and resulted in a gain of approximately $325.9 million, which was recorded in Gain/(loss) on sale of real estate owned Joint Ventures and Partnerships ​ Other Activity Total real estate owned, net of accumulated depreciation 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. The Company did not recognize any impairments in the value of its long-lived assets during the three and nine months ended September 30, 2023 and 2022. 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	9 Months Ended
	Sep. 30, 2023
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.

JOINT VENTURES AND PARTNERSHIPS

JOINT VENTURES AND PARTNERSHIPS	9 Months Ended
	Sep. 30, 2023
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 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. Consolidated joint venture ​ The Company previously held a preferred equity investment in a joint venture that owned a 136 apartment home community located in San Francisco, California. In 2022, the joint venture was deemed to be a VIE and the Company concluded that it was the primary beneficiary of the VIE, and therefore began consolidating the joint venture. In February 2023, the Company took title to the property pursuant to a foreclosure resulting in it being a wholly-owned community. ​ Unconsolidated 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 for the communities held by 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 September 30, 2023 and December 31, 2022 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Number of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating ​ Apartment ​ UDR's Weighted Average ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ Income/(loss) from investments ​ ​ Communities ​ Homes ​ Ownership Interest ​ ​ Investment at ​ Three Months Ended ​ Nine Months Ended ​ September 30, September 30, ​ September 30, ​ December 31, September 30, December 31, ​ September 30, ​ September 30, Joint Ventures 2023 2023 ​ 2023 ​ 2022 2023 2022 ​ 2023 2022 ​ 2023 2022 Operating: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR/MetLife (a) ​ 13 ​ 2,837 ​ 50.1 % ​ 50.1 % ​ $ 231,240 ​ $ 247,160 ​ $ (1,455) ​ $ (1,827) ​ $ (3,930) ​ $ (6,266) UDR/LaSalle (b) ​ 4 ​ 1,328 ​ 51.0 % ​ — % ​ ​ 255,181 ​ ​ — ​ ​ (1,647) ​ ​ — ​ ​ (1,689) ​ ​ — Total Joint Ventures ​ 17 4,165 ​ ​ ​ ​ $ 486,421 ​ $ 247,160 ​ $ (3,102) ​ $ (1,827) ​ $ (5,619) ​ $ (6,266) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Apartment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ Income/(loss) from investments ​ ​ Communities ​ Homes ​ Weighted ​ ​ ​ ​ ​ ​ ​ Investment at ​ Three Months Ended ​ Nine Months Ended Developer Capital Program September 30, ​ September 30, ​ Average ​ Years To ​ UDR September 30, December 31, September 30, ​ September 30, and Real Estate Technology Investments (c) 2023 ​ 2023 ​ Rate ​ Maturity ​ Commitment (d) 2023 2022 2023 2022 2023 2022 Preferred equity investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating (e) ​ 22 ​ 4,718 ​ 9.3 % ​ 3.1 ​ $ 297,177 ​ ​ 348,171 ​ ​ 315,438 ​ $ 6,059 ​ $ 4,751 ​ $ 20,643 ​ $ 13,783 Development ​ 2 ​ 1,073 ​ 10.7 % ​ 3.4 ​ ​ 68,207 ​ ​ 80,860 ​ ​ 74,648 ​ ​ 2,152 ​ ​ 1,909 ​ ​ 6,214 ​ ​ 4,190 Total Preferred Equity Investments ​ 24 ​ 5,791 ​ 9.5 % ​ 3.1 ​ ​ 365,384 ​ ​ 429,031 ​ ​ 390,086 ​ ​ 8,211 ​ ​ 6,660 ​ ​ 26,857 ​ ​ 17,973 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate technology investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RETV I (f) ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 18,000 ​ ​ 10,360 ​ ​ 16,601 ​ ​ (876) ​ ​ (1,458) ​ ​ (101) ​ ​ (28,009) RETV II ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 18,000 ​ ​ 14,222 ​ ​ 11,670 ​ ​ 1,547 ​ ​ 122 ​ ​ 1,116 ​ ​ (603) RETV III ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 15,000 ​ ​ 1,423 ​ ​ — ​ ​ (117) ​ ​ — ​ ​ (117) ​ ​ — RET Strategic Fund ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 25,000 ​ ​ 11,040 ​ ​ 8,078 ​ ​ (87) ​ ​ (37) ​ ​ (183) ​ ​ (115) RET ESG ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 10,000 ​ ​ 2,719 ​ ​ 2,898 ​ ​ (52) ​ ​ (72) ​ ​ (181) ​ ​ (72) Total Preferred Equity Investments and Real Estate Technology Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 468,795 ​ ​ 429,333 ​ ​ 8,626 ​ ​ 5,215 ​ ​ 27,391 ​ ​ (10,826) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sold joint ventures and other investments (g) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ — ​ ​ 70,501 ​ ​ (16) ​ ​ 6,615 ​ ​ 3,140 ​ ​ 21,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Joint Ventures, Developer Capital Program and Real Estate Technology Investments, net (a) ​ ​ ​ ​ $ 955,216 ​ $ 746,994 ​ $ 5,508 $ 10,003 ​ $ 24,912 $ 4,186 (a) As of September 30, 2023 and December 31, 2022, the Company’s negative investment in one UDR/MetLife community of $8.7 million and $7.5 million, respectively, is recorded in Accounts payable, accrued expenses, and other liabilities on the Consolidated Balance Sheets. (b) In June 2023, the Company formed a new real estate joint venture, UDR/LaSalle, with LaSalle Investment Management on behalf of an institutional client (“LaSalle”). Four operating communities, located in various markets, were contributed by the Company. The joint venture partner paid the Company approximately $247.9 million at formation of the joint venture. The Company will have the potential to earn a promoted return should certain return hurdles be achieved . Our initial investment was $258.2 million and consisted solely of our equity in the four operating communities contributed to the joint venture. (c) 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. At September 30, 2023, our preferred equity investment portfolio consisted of 24 communities located in various markets, consisting of 5,791 completed or under development homes. In addition, the Company’s preferred equity investments include five investments that receive a variable percentage of the value created from the project upon a capital or liquidating event. During the nine months ended September 30, 2023, the Company did not enter into or fund any new preferred equity investments or redeem any preferred equity investments. (d) Represents UDR’s maximum funding commitment only and therefore excludes other activity such as income from investments. (e) In June 2023, two preferred equity investment agreements were amended. In connection with the amendments, the Company funded an incremental $17.0 million to one joint venture, which was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to April 2025, and funded an incremental $1.8 million to the other joint venture, which was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to June 2025. (f) The Company recognized $(0.9) million and $(1.5) million of investment income/(loss) from RETV I for the three months ended September 30, 2023 and 2022, respectively, and $(0.1 ) million and $(28.0) million of investment income/(loss) from RETV for the nine months ended September 30, 2023 and 2022, respectively, which primarily related to unrealized gains/(losses) from one portfolio investment held by RETV I, SmartRent, Inc. (“SmartRent”). (g) The agreement for one preferred equity investment was amended, resulting in the Company’s investment, inclusive of accrued preferred return, being classified as a note receivable on the Consolidated Balance Sheet as of September 30, 2023. (See Note 2, Significant Accounting Policies for further discussion.) ​ As of September 30, 2023 and December 31, 2022, the Company had deferred fees of $7.6 million and $8.1 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 $1.8 million and $ 1.3 million for the three months ended September 30, 2023 and 2022, respectively, and $4.5 million and $3.8 million for the nine months ended September 30, 2023 and 2022, 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 consider various factors to determine if a decrease in the value of our Investment in and advances to unconsolidated joint ventures, net Combined summary balance sheets relating to the unconsolidated joint ventures and partnerships (not just our proportionate share) are presented below as of September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2023 2022 Total real estate, net $ 3,131,728 $ 2,739,784 Investments, at fair value ​ ​ 234,081 ​ ​ 213,743 Cash and cash equivalents ​ 78,614 ​ 38,999 Other assets ​ ​ 148,478 ​ 121,759 Total assets $ 3,592,901 $ 3,114,285 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,966,904 ​ $ 1,937,329 Accounts payable and accrued liabilities ​ ​ 166,978 ​ ​ 217,148 Total liabilities ​ 2,133,882 ​ 2,154,477 Total equity $ 1,459,019 $ 959,808 ​ Combined summary financial information relating to the unconsolidated joint ventures’ and partnerships’ operations (not just our proportionate share) is presented below for the three and nine months ended September 30, 2023 and 2022 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Total revenues $ 70,375 $ 38,093 $ 194,752 $ 110,451 Property operating expenses ​ 32,268 ​ 18,326 ​ 86,779 ​ 52,805 Real estate depreciation and amortization ​ 34,874 ​ 16,233 ​ 84,907 ​ 50,689 Gain/(loss) on sale of property ​ ​ — ​ ​ — ​ ​ — ​ ​ 127,542 Operating income/(loss) ​ 3,233 ​ ​ 3,534 ​ 23,066 ​ ​ 134,499 Interest expense ​ (18,138) ​ (9,829) ​ (65,202) ​ (26,598) Net realized gain/(loss) on held investments ​ ​ — ​ ​ 19,331 ​ ​ 38,863 ​ ​ 95,953 Net unrealized gain/(loss) on held investments ​ ​ 13,580 ​ ​ (24,561) ​ ​ (21,757) ​ ​ (263,202) Other income/(loss) ​ ​ (1,234) ​ ​ (478) ​ ​ (236) ​ ​ (877) Net income/(loss) $ (2,559) $ (12,003) $ (25,266) $ (60,225) ​

LEASES

LEASES	9 Months Ended
	Sep. 30, 2023
LEASES
LEASES	6. LEASES Lessee - Ground Leases UDR has six communities that are subject to ground leases, under which UDR is the lessee, that expire 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 and nine months ended September 30, 2023 and 2022. As of September 30, 2023 and December 31, 2022, 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 42.1 years and 42.6 years at September 30, 2023 and December 31, 2022, respectively, and the weighted average discount rate was 5.0% at both September 30, 2023 and December 31, 2022. Future minimum lease payments and total operating lease liabilities from our ground leases as of September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2023 ​ $ 3,110 2024 ​ ​ 12,442 2025 ​ ​ 12,442 2026 ​ ​ 12,442 2027 ​ ​ 12,442 Thereafter ​ ​ 417,895 Total future minimum lease payments (undiscounted) ​ ​ 470,773 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (284,072) Total operating lease liabilities (discounted) ​ $ 186,701 ​ 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 September 30, ​ Nine Months Ended September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Lease expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,293 ​ $ 3,226 ​ $ 9,877 ​ $ 9,760 Variable lease expense (a) ​ ​ 42 ​ ​ 28 ​ ​ 103 ​ ​ 81 Total operating lease expense (b)(c) ​ $ 3,335 ​ $ 3,254 ​ $ 9,980 ​ $ 9,841 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of a community’s revenue. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the nine months ended September 30, 2023, Operating lease right-of-use assets and Operating lease liabilities amortized by $2.6 million and $2.5 million, respectively. For the nine months ended September 30, 2022, Operating lease right-of-use assets and Operating lease liabilities amortized by $2.5 million and $2.4 million, respectively. Due to the net impact of the amortization, the Company recorded less than $0.1 million and $0.1 million of total operating lease expense during the three months ended September 30, 2023 and 2022, respectively, and $0.1 million and $0.3 million of total operating lease expense during the nine months ended September 30, 2023 and 2022, respectively. ​ 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 September 30, 2023, our apartment home leases generally have initial terms of 12 months or less. As of September 30, 2023, our retail and commercial space leases generally have initial terms of between 5 and 15 years and represent approximately 1% to 2% of our total lease revenue. Our apartment home leases are generally renewable at the end of the lease term, subject to potential changes 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 September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2023 ​ $ 6,564 2024 ​ ​ 26,561 2025 ​ ​ 23,717 2026 ​ ​ 21,032 2027 ​ ​ 17,155 Thereafter ​ ​ 70,079 Total future minimum lease payments (a) ​ $ 165,108 (a) 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 $0.2 million and $0.1 million for the three months ended September 30, 2023 and 2022, respectively, and $1.0 million and $0.5 million during the nine months ended September 30, 2023 and 2022, respectively.

SECURED AND UNSECURED DEBT, NET

SECURED AND UNSECURED DEBT, NET	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of September 30, 2023 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ September 30, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2023 2022 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 1,214,110 ​ $ 1,005,622 3.48 % 4.9 20 Deferred financing costs and other non-cash adjustments (b) ​ (2,823) ​ 19,712 Total fixed rate secured debt, net ​ 1,211,287 ​ 1,025,334 3.48 % 4.9 20 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 4.42 % 8.5 1 Deferred financing costs ​ (47) ​ (53) Total variable rate secured debt, net ​ 26,953 ​ 26,947 4.42 % 8.5 1 Total Secured Debt, net ​ 1,238,240 ​ 1,052,281 3.45 % 5.0 21 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2026 (d) (m) ​ — ​ — — % 2.3 Borrowings outstanding under unsecured commercial paper program due October 2023 (e) (m) ​ ​ 380,000 ​ ​ 300,000 ​ 5.59 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2024 ​ 26,700 ​ 28,015 6.19 % 0.3 Term Loan due January 2027 (d) (m) ​ — ​ 175,000 — % 3.3 Fixed Rate Debt ​ ​ Term Loan due January 2027 (d) (m) ​ ​ 350,000 ​ 175,000 3.36 % 3.3 ​ ​ 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 1.0 2.95% Medium-Term Notes due September 2026 (g) (m) ​ 300,000 ​ 300,000 2.89 % 2.9 3.50% Medium-Term Notes due July 2027 (net of discounts of $264 and $317, respectively) (h) (m) ​ ​ 299,736 ​ ​ 299,683 ​ 4.03 % 3.8 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $509 and $598, respectively) (m) ​ ​ 299,491 ​ ​ 299,402 ​ 3.50 % 4.3 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $3 and $4, respectively) (i) (m) ​ ​ 299,997 ​ ​ 299,996 ​ 4.27 % 5.3 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $8,637 and $9,667, respectively) (j) (m) ​ ​ 608,637 ​ ​ 609,667 ​ 3.32 % 6.3 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of premiums of $9,408 and $10,304, respectively) (k) (m) ​ ​ 609,408 ​ ​ 610,304 ​ 3.01 % 7.9 ​ ​ 2.10% Medium-Term Notes due August 2032 (net of discounts of $311 and $338, respectively) (m) ​ ​ 399,689 ​ ​ 399,662 ​ 2.10 % 8.8 ​ ​ 1.90% Medium-Term Notes due March 2033 (net of discounts of $1,140 and $1,230, respectively) (m) ​ ​ 348,860 ​ ​ 348,770 ​ 1.90 % 9.5 ​ ​ 2.10% Medium-Term Notes due June 2033 (net of discounts of $966 and $1,041, respectively) (m) ​ ​ 299,034 ​ ​ 298,959 ​ 2.10 % 9.7 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $978 and $1,045, respectively) (l) (m) ​ ​ 299,022 ​ ​ 298,955 ​ 3.13 % 11.1 ​ ​ Other ​ 2 ​ 5 Deferred financing costs ​ (21,638) ​ (24,040) Total Unsecured Debt, net ​ 4,514,582 ​ 4,435,022 3.34 % 6.1 Total Debt, net ​ $ 5,752,822 ​ $ 5,487,303 3.37 % 5.9 ​ 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 September 30, 2023, secured debt encumbered 13% of UDR’s total real estate owned based upon gross book value (approximately 87% 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 term of the underlying debt instrument. In August 2023, the Company assumed secured fixed rate mortgage notes payable with an outstanding balance of $209.4 million and a fair value of $191.7 million in connection with the acquisition of six operating communities. The six mortgages had outstanding balances ranging from $28.0 million to $40.0 million and carry interest rates from 3.24% to 4.12% (see Note 3, Real Estate Owned ). (b) Interest expense ​ (c) (d) Based on the Company’s current credit rating, the Revolving Credit Facility has an interest rate equal to Adjusted SOFR plus a margin of 75.5 basis points and a facility fee of 15 basis points, and the Term Loan has an interest rate equal to Adjusted SOFR plus a margin of 83.0 basis points. Depending on the Company’s credit rating, the margin under the Revolving Credit Facility ranges from 70 to 140 basis points, the facility fee ranges from 10 to 30 basis points, and the margin under the Term Loan ranges from 75 to 160 basis points. F urther, the Credit Agreement includes sustainability adjustments pursuant to which the applicable margin for the Revolving Credit Facility and the Term Loan were reduced by two basis points upon the Company receiving certain green building certifications, which is reflected in the margins noted above. In August 2021 and March 2023, the Company entered into five interest rate swaps totaling $350.0 million of notional value, which became effective in July 2022 and in March 2023, to hedge against interest rate risk on all or a portion of the Term Loan debt until July 2025. $350.0 million of the Term Loan debt has a weighted average interest rate, inclusive of the impact of the interest rate swaps, of 3.36% from March 2023 until January 2024, $262.5 million of the Term Loan debt has a weighted average interest rate, inclusive of the impact of interest rate swaps, of 2.68% from January 2024 until July 2024, and $175.0 million of the Term Loan debt has a weighted average interest rate, inclusive of the impact of interest rate swaps, of 1.43% from July 2024 until July 2025 ​ 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 September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 2022 ​ Total revolving credit facility ​ $ 1,300,000 ​ $ 1,300,000 ​ Borrowings outstanding at end of period (1) ​ — ​ — ​ Weighted average daily borrowings during the period ended ​ 2,747 ​ 3,776 ​ Maximum daily borrowings during the period ended ​ 250,000 ​ 205,000 ​ Weighted average interest rate during the period ended ​ 5.6 % 3.9 % Interest rate at end of the period ​ — % — % (1) Excludes $2.3 million and $2.6 million of letters of credit at September 30, 2023 and December 31, 2022, respectively . (e) The following is a summary of short-term bank borrowings under the unsecured commercial paper program at September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Total unsecured commercial paper program $ 700,000 ​ $ 700,000 ​ Borrowings outstanding at end of period ​ 380,000 ​ 300,000 ​ Weighted average daily borrowings during the period ended ​ 378,941 ​ 405,671 ​ Maximum daily borrowings during the period ended ​ 505,000 ​ 700,000 ​ Weighted average interest rate during the period ended ​ 5.3 % 2.3 % Interest rate at end of the period ​ 5.6 % 4.7 % ​ (f) The following is a summary of short-term bank borrowings under the Working Capital Credit Facility at September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Total working capital credit facility ​ $ 75,000 ​ $ 75,000 ​ Borrowings outstanding at end of period ​ 26,700 ​ 28,015 ​ Weighted average daily borrowings during the period ended ​ 16,920 ​ 15,080 ​ Maximum daily borrowings during the period ended ​ 57,107 ​ 55,812 ​ Weighted average interest rate during the period ended ​ 5.8 % 3.0 % Interest rate at end of the period ​ 6.2 % 5.2 % ​ (g) (h) (i) (j) The all-in weighted average interest rate, inclusive of the impact of the forward starting swaps and treasury locks, was 3.32% . (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 September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2023 ​ $ 359 ​ $ — ​ $ 359 ​ $ 380,000 (a) $ 380,359 2024 ​ ​ 97,578 ​ ​ — ​ ​ 97,578 ​ ​ 42,344 ​ ​ 139,922 2025 ​ 178,568 ​ — ​ 178,568 ​ — ​ 178,568 2026 ​ 56,665 ​ — ​ 56,665 ​ 300,000 ​ 356,665 2027 ​ 6,931 ​ — ​ 6,931 ​ 650,000 ​ 656,931 2028 ​ 166,518 ​ — ​ 166,518 ​ 300,000 ​ 466,518 2029 ​ 315,802 ​ — ​ 315,802 ​ 300,000 ​ 615,802 2030 ​ 230,759 ​ — ​ 230,759 ​ 600,000 ​ 830,759 2031 ​ 160,930 ​ — ​ 160,930 ​ 600,000 ​ 760,930 2032 ​ — ​ 27,000 ​ 27,000 ​ 400,000 ​ 427,000 Thereafter ​ — ​ — ​ — ​ 950,000 ​ 950,000 Subtotal ​ 1,214,110 ​ 27,000 ​ 1,241,110 ​ 4,522,344 ​ 5,763,454 Non-cash (b) ​ (2,823) ​ (47) ​ (2,870) ​ (7,762) ​ (10,632) Total ​ $ 1,211,287 ​ $ 26,953 ​ $ 1,238,240 ​ $ 4,514,582 ​ $ 5,752,822 (a) All unsecured debt due in the remainder of 2023 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 September 30, 2023 and 2022, respectively, and $2.9 million and $2.9 million, respectively, during the nine months ended September 30, 2023 and 2022, of deferred financing costs into Interest expense. We were in compliance with the covenants of our debt instruments at September 30, 2023.

INCOME_(LOSS) PER SHARE

INCOME/(LOSS) PER SHARE	9 Months Ended
	Sep. 30, 2023
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 ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 ​ Numerator for income/(loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income/(loss) ​ $ 35,419 ​ $ 25,145 ​ $ 438,527 ​ $ 45,112 ​ Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (2,554) ​ (1,533) ​ (27,137) ​ (2,684) ​ Net (income)/loss attributable to noncontrolling interests ​ (7) ​ (7) ​ (23) ​ (34) ​ Net income/(loss) attributable to UDR, Inc. ​ 32,858 ​ 23,605 ​ 411,367 ​ 42,394 ​ Distributions to preferred stockholders — Series E (Convertible) ​ (1,221) ​ (1,106) ​ (3,626) ​ (3,307) ​ Income/(loss) attributable to common stockholders - basic and diluted ​ ​ 31,637 ​ ​ 22,499 ​ ​ 407,741 ​ ​ 39,087 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for income/(loss) per share: ​ ​ ​ ​ ​ Weighted average common shares outstanding ​ 329,130 ​ 324,983 ​ 329,207 ​ 320,654 ​ Non-vested restricted stock awards ​ (370) ​ (282) ​ (372) ​ (276) ​ Denominator for basic income/(loss) per share ​ 328,760 ​ 324,701 ​ 328,835 ​ 320,378 ​ Incremental shares issuable from assumed conversion of unvested LTIP Units, performance units, unvested restricted stock and shares issuable upon settlement of forward sales agreements ​ 441 ​ 985 ​ 448 ​ 1,251 ​ Denominator for diluted income/(loss) per share ​ 329,201 ​ 325,686 ​ 329,283 ​ 321,629 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) per weighted average common share: ​ ​ ​ ​ ​ Basic ​ $ 0.10 ​ $ 0.07 ​ $ 1.24 ​ $ 0.12 ​ Diluted ​ $ 0.10 ​ $ 0.07 ​ $ 1.24 ​ $ 0.12 ​ ​ 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”), performance 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 and nine months ended September 30, 2023 and 2022, the effect of the conversion of the OP Units, DownREIT Units and the Company’s Series E preferred stock was not dilutive and therefore not included in the above calculation. In July 2021, 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 July 2017. During the three and nine months ended September 30, 2023, the Company did not sell any shares of common stock through its ATM program. As of September 30, 2023, we had 14.0 million shares of common stock available for future issuance under the ATM program. 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. For the three and nine months ended September 30, 2023, the Company did not enter into any forward purchase agreements under its continuous equity program. ​ During the three and nine months ended September 30, 2023, the Company repurchased 0.6 million shares of its common stock at an average price of $40.13 per share for total consideration of approximately $25.0 million under its share repurchase program. ​ The following table sets forth the additional shares of common stock outstanding, by equity instrument, if converted to common stock for each of the three and nine months ended September 30, 2023 and 2022 (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ OP/DownREIT Units 22,511 21,474 21,699 21,514 Convertible preferred stock 2,908 2,918 2,908 2,918 Unvested LTIP Units and unvested restricted stock 441 985 448 1,251 ​

NONCONTROLLING INTERESTS

NONCONTROLLING INTERESTS	9 Months Ended
	Sep. 30, 2023
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 at December 31, 2022 $ 839,850 ​ Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (65,799) ​ OP Units issued for real estate, net ​ 141,359 ​ Conversion of OP Units/DownREIT Units to Common Stock or Cash ​ (26,537) ​ Net income/(loss) attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ 27,137 ​ Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (29,203) ​ Redeemable Long-Term and Short-Term Incentive Plan Units ​ ​ 20,474 ​ Allocation of other comprehensive income/(loss) ​ (12) ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership at September 30, 2023 ​ $ 907,269 ​ ​ Noncontrolling Interests Noncontrolling interests represent interests of unrelated partners 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

FAIR VALUE OF DERIVATIVES AND F

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 and December 31, 2022, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at September 30, 2023, 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 ​ ​ September 30, ​ September 30, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2023 (a) ​ 2023 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable, net (b) ​ $ 209,297 ​ $ 211,278 ​ $ — ​ $ — ​ $ 211,278 Equity securities (c) ​ ​ 17,780 ​ ​ 17,780 ​ ​ 17,780 ​ ​ — ​ ​ — Derivatives - Interest rate contracts (d) ​ 14,150 ​ 14,150 ​ — ​ 14,150 ​ — Total assets ​ $ 241,227 ​ $ 243,208 ​ $ 17,780 ​ $ 14,150 ​ $ 211,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (e) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 1,215,988 ​ $ 1,078,613 ​ $ — ​ $ — ​ $ 1,078,613 Secured debt instruments - variable rate: (e) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (e) ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 26,700 ​ ​ 26,700 ​ ​ — ​ ​ — ​ ​ 26,700 Commercial paper program ​ ​ 380,000 ​ ​ 380,000 ​ ​ — ​ ​ — ​ ​ 380,000 Unsecured notes ​ ​ 4,129,520 ​ ​ 3,418,985 ​ ​ — ​ ​ — ​ ​ 3,418,985 Total liabilities ​ $ 5,779,208 ​ $ 4,931,298 ​ $ — ​ $ — ​ $ 4,931,298 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (f) ​ $ 907,269 ​ $ 907,269 ​ $ — ​ $ 907,269 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2022, 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 ​ 2022 (a) ​ 2022 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable, net (b) ​ $ 54,707 ​ $ 55,514 ​ $ — ​ $ — ​ $ 55,514 Equity securities (c) ​ ​ 9,707 ​ ​ 9,707 ​ ​ 9,707 ​ ​ — ​ ​ — Derivatives - Interest rate contracts (d) ​ 15,270 ​ 15,270 ​ — ​ 15,270 ​ — Total assets ​ $ 79,684 ​ $ 80,491 ​ $ 9,707 ​ $ 15,270 ​ $ 55,514 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (e) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 1,028,169 ​ $ 909,041 ​ $ — ​ $ — ​ $ 909,041 Secured debt instruments - variable rate: (e) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (e) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 28,015 ​ ​ 28,015 ​ ​ — ​ ​ — ​ ​ 28,015 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 4,131,047 ​ ​ 3,448,632 ​ ​ — ​ ​ — ​ ​ 3,448,632 Total liabilities ​ $ 5,514,231 ​ $ 4,712,688 ​ $ — ​ $ — ​ $ 4,712,688 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (f) ​ $ 839,850 ​ $ 839,850 ​ $ — ​ $ 839,850 ​ $ — (a) Certain balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) The Company holds a direct investment in a publicly traded real estate technology company, SmartRent. The investment is valued at the market price on September 30, 2023 and December 31, 2022. The Company currently classifies the investment as Level 1 in the fair value hierarchy. During the nine months ended September 30, 2023, the Company increased its direct investment in SmartRent due to stock distributions from its unconsolidated real estate technology investments. (d) See Note 11, Derivatives and Hedging Activity . (e) See Note 7, Secured and Unsecured Debt, Net . (f) See Note 9, Noncontrolling Interests. There were no transfers into or out of any of the levels of the fair value hierarchy during the nine months ended September 30, 2023. 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 swaps and caps 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 September 30, 2023 and December 31, 2022, 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 September 30, 2023 and December 31, 2022, 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.

DERIVATIVES AND HEDGING ACTIVIT

DERIVATIVES AND HEDGING ACTIVITY	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023, 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 and caps ​ 6 ​ $ 369,880 ​ 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. As of September 30, 2023, no derivatives not designated as hedges were held by the Company. Tabular Disclosure of Fair Values of Derivative Instruments on the 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 September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ September 30, ​ December 31, ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ 14,150 ​ $ 15,270 ​ $ — ​ $ — ​ 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 and nine months ended September 30, 2023 and 2022 ( 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 2023 2022 2023 2022 2023 2022 Three Months Ended September 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ 1,314 ​ $ 5,048 ​ $ 2,110 ​ $ 313 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ 5,336 ​ $ 13,988 ​ $ 5,332 ​ $ 28 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Total amount of Interest expense ​ $ 44,664 ​ $ 39,905 ​ $ 133,519 ​ $ 112,653 ​ 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 September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheets ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount September 30, 2023 ​ $ 14,150 ​ $ — ​ $ 14,150 ​ $ — ​ $ — ​ $ 14,150 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ $ 15,270 ​ $ — ​ $ 15,270 ​ $ — ​ $ — ​ $ 15,270 (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 Sheets ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount September 30, 2023 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — (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	9 Months Ended
	Sep. 30, 2023
STOCK BASED COMPENSATION
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 $7.1 million and $6.7 million during the three months ended September 30, 2023 and 2022, respectively, and $22.8 million and $20.5 million during the nine months ended September 30, 2023 and 2022, respectively, which are included in General and Administrative

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2023
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	13. COMMITMENTS AND CONTINGENCIES Commitments The following summarizes the Company’s commitments at September 30, 2023 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Real estate commitments ​ ​ ​ ​ ​ ​ ​ ​ ​ Wholly-owned — under development 2 ​ $ 139,143 ​ $ 48,357 Wholly-owned — redevelopment (b) 8 ​ ​ 35,253 ​ ​ 69,747 Other unconsolidated investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate technology investments (c) ​ - ​ ​ 50,931 ​ ​ 45,069 ​ Total ​ $ 225,327 ​ $ 163,173 (a) Represents UDR’s investment as of September 30, 2023. (b) Projects consist of unit renovations and/or renovation of related common area amenities. (c) As of September 30, 2023, the investments were recorded in either Investment in and advances to unconsolidated joint ventures, net or Other Assets on the Consolidated Balance Sheets . ​ 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	9 Months Ended
	Sep. 30, 2023
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 3.25% of property revenue, and land rent. Property management expense covers costs directly related to consolidated property operations, inclusive of corporate management, regional supervision, accounting and other costs. 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 July 1, 2022 (for quarter-to-date comparison) and January 1, 2022 (for year-to-date comparison) and held as of September 30, 2023. 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 classified as 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 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 and nine months ended September 30, 2023 and 2022. ​ 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 ​ Other revenue is generated by services provided by the Company to its retail and residential tenants and other unrelated third parties. Revenue is measured based on consideration specified in contracts with customers. The Company recognizes when it satisfies a performance obligation by providing the services specified in a contract to the customer. ​ 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 and nine months ended September 30, 2023 and 2022, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, (a) ​ September 30, (b) ​ 2023 2022 2023 2022 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 119,203 ​ $ 114,322 ​ $ 351,822 ​ $ 334,229 Mid-Atlantic Region ​ 78,462 ​ 74,999 ​ 231,564 ​ 219,043 Northeast Region ​ 79,958 ​ 74,857 ​ 225,868 ​ 208,950 Southeast Region ​ 57,035 ​ 53,811 ​ 169,613 ​ 154,306 Southwest Region ​ 37,872 ​ 36,801 ​ 113,139 ​ 106,220 Non-Mature Communities/Other ​ 22,364 ​ 22,057 ​ 80,536 ​ 55,613 Total segment and consolidated lease revenue ​ $ 394,894 ​ $ 376,847 ​ $ 1,172,542 ​ $ 1,078,361 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 3,106 ​ $ 3,220 ​ $ 8,837 ​ $ 9,059 Mid-Atlantic Region ​ 3,436 ​ 3,149 ​ 8,884 ​ 8,534 Northeast Region ​ 2,095 ​ 2,295 ​ 5,282 ​ 5,232 Southeast Region ​ 2,571 ​ 2,245 ​ 7,030 ​ 6,576 Southwest Region ​ 1,813 ​ 1,647 ​ 4,795 ​ 4,337 Non-Mature Communities/Other ​ 444 ​ 620 ​ 2,394 ​ 1,853 Total segment and consolidated other revenue ​ $ 13,465 ​ $ 13,176 ​ $ 37,222 ​ $ 35,591 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 122,309 ​ $ 117,542 ​ $ 360,659 ​ $ 343,288 Mid-Atlantic Region ​ 81,898 ​ 78,148 ​ 240,448 ​ 227,577 Northeast Region ​ 82,053 ​ 77,152 ​ 231,150 ​ 214,182 Southeast Region ​ 59,606 ​ 56,056 ​ 176,643 ​ 160,882 Southwest Region ​ 39,685 ​ 38,448 ​ 117,934 ​ 110,557 Non-Mature Communities/Other ​ 22,808 ​ 22,677 ​ 82,930 ​ 57,466 Total segment and consolidated rental income ​ $ 408,359 ​ $ 390,023 ​ $ 1,209,764 ​ $ 1,113,952 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ West Region ​ $ 90,574 ​ $ 87,095 ​ $ 269,108 ​ $ 256,265 Mid-Atlantic Region ​ 55,921 ​ 53,317 ​ 165,552 ​ 156,286 Northeast Region ​ 53,392 ​ 49,990 ​ 152,212 ​ 139,301 Southeast Region ​ 40,667 ​ 37,854 ​ 121,018 ​ 108,904 Southwest Region ​ 25,587 ​ 23,611 ​ 75,449 ​ 69,356 Non-Mature Communities/Other ​ 12,515 ​ 13,151 ​ 47,541 ​ 33,394 Total segment and consolidated NOI ​ 278,656 ​ 265,018 ​ 830,880 ​ 763,506 Reconciling items: ​ ​ ​ ​ Joint venture management and other fees ​ 1,772 ​ 1,274 ​ 4,464 ​ 3,778 Property management ​ (13,271) ​ (12,675) ​ (39,317) ​ (36,203) Other operating expenses ​ (4,611) ​ (3,746) ​ (11,902) ​ (13,485) Real estate depreciation and amortization ​ (167,551) ​ (166,781) ​ (505,776) ​ (497,987) General and administrative ​ (15,159) ​ (15,840) ​ (49,091) ​ (47,333) Casualty-related (charges)/recoveries, net ​ 1,928 ​ (901) ​ (3,362) ​ (1,210) Other depreciation and amortization ​ (3,692) ​ (3,430) ​ (11,022) ​ (9,521) Gain/(loss) on sale of real estate owned ​ ​ — ​ ​ — ​ ​ 325,885 ​ ​ — Income/(loss) from unconsolidated entities ​ 5,508 ​ 10,003 ​ 24,912 ​ 4,186 Interest expense ​ (44,664) ​ (39,905) ​ (133,519) ​ (112,653) Interest income and other income/(expense), net ​ (3,069) ​ (7,495) ​ 8,388 ​ (6,934) Tax (provision)/benefit, net ​ (428) ​ (377) ​ (2,013) ​ (1,032) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (2,554) ​ (1,533) ​ (27,137) ​ (2,684) Net (income)/loss attributable to noncontrolling interests ​ (7) ​ (7) ​ (23) ​ (34) Net income/(loss) attributable to UDR, Inc. ​ $ 32,858 ​ $ 23,605 ​ $ 411,367 ​ $ 42,394 (a) Same-Store Community population consisted of 52,291 apartment homes. (b) Same-Store Community population consisted of 51,858 apartment homes. ​ The following table details the assets of UDR’s reportable segments as of September 30, 2023 and December 31, 2022 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 4,415,840 ​ $ 4,363,452 Mid-Atlantic Region ​ 3,295,218 ​ 3,245,297 Northeast Region ​ 3,876,325 ​ 3,834,761 Southeast Region ​ 1,572,392 ​ 1,521,489 Southwest Region ​ 1,319,617 ​ 1,287,332 Non-Mature Communities/Other ​ 1,439,232 ​ 1,317,741 Total segment assets ​ 15,918,624 ​ 15,570,072 Accumulated depreciation ​ (6,117,312) ​ (5,762,501) Total segment assets — net book value ​ 9,801,312 ​ 9,807,571 Reconciling items: ​ ​ Cash and cash equivalents ​ 1,624 ​ 1,193 Restricted cash ​ 30,831 ​ 29,001 Notes receivable, net ​ 209,297 ​ 54,707 Investment in and advances to unconsolidated joint ventures, net ​ 963,927 ​ 754,446 Operating lease right-of-use assets ​ ​ 191,499 ​ ​ 194,081 Other assets ​ 221,572 ​ 197,471 Total consolidated assets ​ $ 11,420,062 ​ $ 11,038,470 (a) Same-Store Community population consisted of 52,291 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., Baltimore and Richmond iii. Northeast Region — Boston, New York and Philadelphia iv. Southeast Region — Tampa, Orlando, Nashville and Other Florida v. Southwest Region — Dallas, Austin and Denver

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2023
SIGNIFICANT ACCOUNTING POLICIES
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 been transferred by the Company, 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 the Company’s 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 assets of the borrower that may include real estate 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 of the existing loans. 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 Accounting Standards Codification (“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 (a) ​ September 30, September 30, December 31, ​ ​ 2023 ​ 2023 ​ 2022 Notes due October 2024 (b) ​ 9.50 % $ 95,734 ​ $ — Note due December 2024 (c) ​ 12.00 % ​ 35,309 ​ ​ 30,377 Note due December 2026 (d) ​ 11.00 % ​ 51,309 ​ ​ 17,292 Note due December 2026 (e) ​ 11.00 % ​ 24,276 ​ ​ 5,813 Notes due June 2027 (f) ​ 18.00 % ​ 3,573 ​ ​ 1,500 Notes Receivable ​ ​ ​ ​ 210,201 ​ ​ 54,982 Allowance for credit losses ​ ​ ​ ​ (904) ​ ​ (275) Total notes receivable, net ​ $ 209,297 ​ $ 54,707 (a) Outstanding note amounts include any accrued and unpaid interest, as applicable. (b) In June 2023, the Company amended the agreement for a preferred equity investment in a joint venture that owns a 471 apartment home operating community located in Philadelphia, Pennsylvania, which resulted in the Company’s investment, inclusive of accrued preferred return, being classified as a note receivable. In connection with the amendment, the Company also advanced $20.0 million to the joint venture, which is also classified as a note receivable (collectively the “Notes”) and was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to January 2024. Furthermore, the contractual interest rate on the Notes increased to 9.5% (previously 8.5% ) in exchange for eliminating the Company’s upside participation in the joint venture. Interest payments accrue monthly and are due at maturity, but can be paid earlier. The Notes had an original scheduled maturity date in October 2023, with three one-year extension options. In September 2023, the developer extended the maturity date to October 2024. Commencing in October 2023, the contractual interest rate on the Notes increased to 10.5% when the developer exercised its option to extend the maturity date of the Notes. (See Note 5, Joint Ventures and Partnerships for further discussion.) (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $32.5 million, of which $30.9 million was funded as of September 30, 2023. During 2023, the terms of this secured note were amended to increase the aggregate commitment from $31.4 million to $32.5 million and to increase the interest rate from 10.0% to 12.0% . Interest payments are due monthly, with the exception of payments from June 2022 to December 2024, which are accrued and added to the principal balance and will be due at maturity of the note. The additional amount accrued and added to the principal balance was $4.4 million as of September 30, 2023. The note is secured by substantially all of the borrower’s assets and 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) December 2024. (d) The Company has a secured mezzanine loan with a third party developer of a 482 apartment home community located in Riverside, California, which is expected to be completed in 2025, with an aggregate commitment of $59.7 million (exclusive of accrued interest), of which $30.7 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (e) The Company has a secured mezzanine loan with a third party developer of a 237 apartment home community located in Menifee, California, which is expected to be completed in 2025, with an aggregate commitment of $24.4 million (exclusive of accrued interest), of which $17.5 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (f) The Company and a syndicate of lenders previously entered into a $16.0 million secured credit facility with an unaffiliated third party. During the nine months ended September 30, 2023, the secured credit facility was amended to provide a new term loan in the amount of $19.0 million, and increase the Company’s commitment from $1.5 million to $3.0 million (exclusive of accrued interest) , all of which has been funded. Interest payments will accrue and be due at maturity of the facility. The facility is secured by substantially all of the borrower’s assets and matures at the earliest of the following: (a) acceleration in the event of default; or (b) June 2027. The Company recognized $5.0 million and $1.0 million of interest income for the notes receivable described above during the three months ended September 30, 2023 and 2022, respectively, and $8.4 million and $2.4 million of interest income for the notes receivable described above during the nine months ended September 30, 2023 and 2022, 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 and nine months ended September 30, 2023 and 2022, 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 September 30, 2023 and December 31, 2022, UDR’s net deferred tax asset/(liability) was $(0.8) million and $(0.8) million, respectively, and are recorded in Accounts payable, accrued expenses and other liabilities 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 and evaluates its tax positions 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 September 30, 2023. UDR and its subsidiaries are subject to federal income tax as well as income tax of various state and local jurisdictions. The tax years 2020 through 2022 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 ​ From time to time 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 the entity’s 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
Lease Receivables	Lease Receivables ​ During the three and nine months ended September 30, 2023 and 2022, the Company performed an analysis in accordance with the ASC 842, Leases, guidance to assess the collectibility of its operating lease receivables. This analysis included an assessment of collectibility of current and future rents and whether those lease payments were no longer probable of collection. In accordance with the leases guidance, if lease payments are no longer deemed to be probable over the life of the lease contract, we recognize revenue only when cash is received, and all existing contractual operating lease receivables and straight-line lease receivables are reserved. ​ As of September 30, 2023, the Company’s multifamily tenant lease receivables balance, net of its reserve, was approximately $9.2 million, including its share from unconsolidated joint ventures. The Company’s retail tenant lease receivables balance (exclusive of straight-line rent receivables), net of its reserve, was approximately $0.3 million, including its share from unconsolidated joint ventures, as of September 30, 2023.

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2023
SIGNIFICANT ACCOUNTING POLICIES
Summary of notes receivable, net	The following table summarizes our Notes receivable, net dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate at ​ Balance Outstanding (a) ​ September 30, September 30, December 31, ​ ​ 2023 ​ 2023 ​ 2022 Notes due October 2024 (b) ​ 9.50 % $ 95,734 ​ $ — Note due December 2024 (c) ​ 12.00 % ​ 35,309 ​ ​ 30,377 Note due December 2026 (d) ​ 11.00 % ​ 51,309 ​ ​ 17,292 Note due December 2026 (e) ​ 11.00 % ​ 24,276 ​ ​ 5,813 Notes due June 2027 (f) ​ 18.00 % ​ 3,573 ​ ​ 1,500 Notes Receivable ​ ​ ​ ​ 210,201 ​ ​ 54,982 Allowance for credit losses ​ ​ ​ ​ (904) ​ ​ (275) Total notes receivable, net ​ $ 209,297 ​ $ 54,707 (a) Outstanding note amounts include any accrued and unpaid interest, as applicable. (b) In June 2023, the Company amended the agreement for a preferred equity investment in a joint venture that owns a 471 apartment home operating community located in Philadelphia, Pennsylvania, which resulted in the Company’s investment, inclusive of accrued preferred return, being classified as a note receivable. In connection with the amendment, the Company also advanced $20.0 million to the joint venture, which is also classified as a note receivable (collectively the “Notes”) and was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to January 2024. Furthermore, the contractual interest rate on the Notes increased to 9.5% (previously 8.5% ) in exchange for eliminating the Company’s upside participation in the joint venture. Interest payments accrue monthly and are due at maturity, but can be paid earlier. The Notes had an original scheduled maturity date in October 2023, with three one-year extension options. In September 2023, the developer extended the maturity date to October 2024. Commencing in October 2023, the contractual interest rate on the Notes increased to 10.5% when the developer exercised its option to extend the maturity date of the Notes. (See Note 5, Joint Ventures and Partnerships for further discussion.) (c) The Company has a secured note with an unaffiliated third party with an aggregate commitment of $32.5 million, of which $30.9 million was funded as of September 30, 2023. During 2023, the terms of this secured note were amended to increase the aggregate commitment from $31.4 million to $32.5 million and to increase the interest rate from 10.0% to 12.0% . Interest payments are due monthly, with the exception of payments from June 2022 to December 2024, which are accrued and added to the principal balance and will be due at maturity of the note. The additional amount accrued and added to the principal balance was $4.4 million as of September 30, 2023. The note is secured by substantially all of the borrower’s assets and 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) December 2024. (d) The Company has a secured mezzanine loan with a third party developer of a 482 apartment home community located in Riverside, California, which is expected to be completed in 2025, with an aggregate commitment of $59.7 million (exclusive of accrued interest), of which $30.7 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (e) The Company has a secured mezzanine loan with a third party developer of a 237 apartment home community located in Menifee, California, which is expected to be completed in 2025, with an aggregate commitment of $24.4 million (exclusive of accrued interest), of which $17.5 million was funded during the nine months ended September 30, 2023. Interest payments accrue for 36 months and are due monthly after the loan has been outstanding for 36 months . The secured mezzanine loan has a scheduled maturity date in December 2026, with two one-year extension options. (f) The Company and a syndicate of lenders previously entered into a $16.0 million secured credit facility with an unaffiliated third party. During the nine months ended September 30, 2023, the secured credit facility was amended to provide a new term loan in the amount of $19.0 million, and increase the Company’s commitment from $1.5 million to $3.0 million (exclusive of accrued interest) , all of which has been funded. Interest payments will accrue and be due at maturity of the facility. The facility is secured by substantially all of the borrower’s assets and matures at the earliest of the following: (a) acceleration in the event of default; or (b) June 2027.

REAL ESTATE OWNED (Tables)

REAL ESTATE OWNED (Tables)	9 Months Ended
	Sep. 30, 2023
REAL ESTATE OWNED
Summary of carrying amounts for real estate owned (at cost)	The following table summarizes the carrying amounts for our real estate owned (at cost) as of September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Land ​ $ 2,558,608 ​ $ 2,539,499 Depreciable property — held and used: ​ ​ ​ Land improvements ​ 250,623 ​ 254,578 Building, improvements, and furniture, fixtures and equipment ​ 12,920,237 ​ 12,521,838 Real estate intangible assets ​ ​ 50,013 ​ ​ 50,013 Under development: ​ ​ Land and land improvements ​ 16,576 ​ 43,711 Building, improvements, and furniture, fixtures and equipment ​ 122,567 ​ 146,394 Real estate held for disposition: ​ ​ Building, improvements, and furniture, fixtures and equipment ​ — ​ 14,039 Real estate owned ​ 15,918,624 ​ 15,570,072 Accumulated depreciation (a) ​ (6,117,312) ​ (5,762,501) Real estate owned, net ​ $ 9,801,312 ​ $ 9,807,571 (a) Accumulated depreciation is inclusive of $16.2 million and $13.1 million of accumulated amortization related to real estate intangible assets as of September 30, 2023 and December 31, 2022, respectively.

JOINT VENTURES AND PARTNERSHI_2

JOINT VENTURES AND PARTNERSHIPS (Tables)	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 and December 31, 2022 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Number of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating ​ Apartment ​ UDR's Weighted Average ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ Income/(loss) from investments ​ ​ Communities ​ Homes ​ Ownership Interest ​ ​ Investment at ​ Three Months Ended ​ Nine Months Ended ​ September 30, September 30, ​ September 30, ​ December 31, September 30, December 31, ​ September 30, ​ September 30, Joint Ventures 2023 2023 ​ 2023 ​ 2022 2023 2022 ​ 2023 2022 ​ 2023 2022 Operating: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ UDR/MetLife (a) ​ 13 ​ 2,837 ​ 50.1 % ​ 50.1 % ​ $ 231,240 ​ $ 247,160 ​ $ (1,455) ​ $ (1,827) ​ $ (3,930) ​ $ (6,266) UDR/LaSalle (b) ​ 4 ​ 1,328 ​ 51.0 % ​ — % ​ ​ 255,181 ​ ​ — ​ ​ (1,647) ​ ​ — ​ ​ (1,689) ​ ​ — Total Joint Ventures ​ 17 4,165 ​ ​ ​ ​ $ 486,421 ​ $ 247,160 ​ $ (3,102) ​ $ (1,827) ​ $ (5,619) ​ $ (6,266) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Apartment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) from investments ​ Income/(loss) from investments ​ ​ Communities ​ Homes ​ Weighted ​ ​ ​ ​ ​ ​ ​ Investment at ​ Three Months Ended ​ Nine Months Ended Developer Capital Program September 30, ​ September 30, ​ Average ​ Years To ​ UDR September 30, December 31, September 30, ​ September 30, and Real Estate Technology Investments (c) 2023 ​ 2023 ​ Rate ​ Maturity ​ Commitment (d) 2023 2022 2023 2022 2023 2022 Preferred equity investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating (e) ​ 22 ​ 4,718 ​ 9.3 % ​ 3.1 ​ $ 297,177 ​ ​ 348,171 ​ ​ 315,438 ​ $ 6,059 ​ $ 4,751 ​ $ 20,643 ​ $ 13,783 Development ​ 2 ​ 1,073 ​ 10.7 % ​ 3.4 ​ ​ 68,207 ​ ​ 80,860 ​ ​ 74,648 ​ ​ 2,152 ​ ​ 1,909 ​ ​ 6,214 ​ ​ 4,190 Total Preferred Equity Investments ​ 24 ​ 5,791 ​ 9.5 % ​ 3.1 ​ ​ 365,384 ​ ​ 429,031 ​ ​ 390,086 ​ ​ 8,211 ​ ​ 6,660 ​ ​ 26,857 ​ ​ 17,973 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate technology investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RETV I (f) ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 18,000 ​ ​ 10,360 ​ ​ 16,601 ​ ​ (876) ​ ​ (1,458) ​ ​ (101) ​ ​ (28,009) RETV II ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 18,000 ​ ​ 14,222 ​ ​ 11,670 ​ ​ 1,547 ​ ​ 122 ​ ​ 1,116 ​ ​ (603) RETV III ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 15,000 ​ ​ 1,423 ​ ​ — ​ ​ (117) ​ ​ — ​ ​ (117) ​ ​ — RET Strategic Fund ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 25,000 ​ ​ 11,040 ​ ​ 8,078 ​ ​ (87) ​ ​ (37) ​ ​ (183) ​ ​ (115) RET ESG ​ N/A ​ N/A ​ N/A ​ ​ N/A ​ ​ 10,000 ​ ​ 2,719 ​ ​ 2,898 ​ ​ (52) ​ ​ (72) ​ ​ (181) ​ ​ (72) Total Preferred Equity Investments and Real Estate Technology Investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 468,795 ​ ​ 429,333 ​ ​ 8,626 ​ ​ 5,215 ​ ​ 27,391 ​ ​ (10,826) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Sold joint ventures and other investments (g) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ — ​ ​ 70,501 ​ ​ (16) ​ ​ 6,615 ​ ​ 3,140 ​ ​ 21,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Joint Ventures, Developer Capital Program and Real Estate Technology Investments, net (a) ​ ​ ​ ​ $ 955,216 ​ $ 746,994 ​ $ 5,508 $ 10,003 ​ $ 24,912 $ 4,186 (a) As of September 30, 2023 and December 31, 2022, the Company’s negative investment in one UDR/MetLife community of $8.7 million and $7.5 million, respectively, is recorded in Accounts payable, accrued expenses, and other liabilities on the Consolidated Balance Sheets. (b) In June 2023, the Company formed a new real estate joint venture, UDR/LaSalle, with LaSalle Investment Management on behalf of an institutional client (“LaSalle”). Four operating communities, located in various markets, were contributed by the Company. The joint venture partner paid the Company approximately $247.9 million at formation of the joint venture. The Company will have the potential to earn a promoted return should certain return hurdles be achieved . Our initial investment was $258.2 million and consisted solely of our equity in the four operating communities contributed to the joint venture. (c) 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. At September 30, 2023, our preferred equity investment portfolio consisted of 24 communities located in various markets, consisting of 5,791 completed or under development homes. In addition, the Company’s preferred equity investments include five investments that receive a variable percentage of the value created from the project upon a capital or liquidating event. During the nine months ended September 30, 2023, the Company did not enter into or fund any new preferred equity investments or redeem any preferred equity investments. (d) Represents UDR’s maximum funding commitment only and therefore excludes other activity such as income from investments. (e) In June 2023, two preferred equity investment agreements were amended. In connection with the amendments, the Company funded an incremental $17.0 million to one joint venture, which was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to April 2025, and funded an incremental $1.8 million to the other joint venture, which was used to pay down the senior construction loan in connection with an extension of the maturity date of the senior construction loan to June 2025. (f) The Company recognized $(0.9) million and $(1.5) million of investment income/(loss) from RETV I for the three months ended September 30, 2023 and 2022, respectively, and $(0.1 ) million and $(28.0) million of investment income/(loss) from RETV for the nine months ended September 30, 2023 and 2022, respectively, which primarily related to unrealized gains/(losses) from one portfolio investment held by RETV I, SmartRent, Inc. (“SmartRent”). (g) The agreement for one preferred equity investment was amended, resulting in the Company’s investment, inclusive of accrued preferred return, being classified as a note receivable on the Consolidated Balance Sheet as of September 30, 2023. (See Note 2, Significant Accounting Policies for further discussion.) ​
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 September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2023 2022 Total real estate, net $ 3,131,728 $ 2,739,784 Investments, at fair value ​ ​ 234,081 ​ ​ 213,743 Cash and cash equivalents ​ 78,614 ​ 38,999 Other assets ​ ​ 148,478 ​ 121,759 Total assets $ 3,592,901 $ 3,114,285 ​ ​ ​ ​ ​ ​ ​ Third party debt, net ​ $ 1,966,904 ​ $ 1,937,329 Accounts payable and accrued liabilities ​ ​ 166,978 ​ ​ 217,148 Total liabilities ​ 2,133,882 ​ 2,154,477 Total equity $ 1,459,019 $ 959,808
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 and nine months ended September 30, 2023 and 2022 ( dollars in thousands : ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2023 2022 2023 2022 Total revenues $ 70,375 $ 38,093 $ 194,752 $ 110,451 Property operating expenses ​ 32,268 ​ 18,326 ​ 86,779 ​ 52,805 Real estate depreciation and amortization ​ 34,874 ​ 16,233 ​ 84,907 ​ 50,689 Gain/(loss) on sale of property ​ ​ — ​ ​ — ​ ​ — ​ ​ 127,542 Operating income/(loss) ​ 3,233 ​ ​ 3,534 ​ 23,066 ​ ​ 134,499 Interest expense ​ (18,138) ​ (9,829) ​ (65,202) ​ (26,598) Net realized gain/(loss) on held investments ​ ​ — ​ ​ 19,331 ​ ​ 38,863 ​ ​ 95,953 Net unrealized gain/(loss) on held investments ​ ​ 13,580 ​ ​ (24,561) ​ ​ (21,757) ​ ​ (263,202) Other income/(loss) ​ ​ (1,234) ​ ​ (478) ​ ​ (236) ​ ​ (877) Net income/(loss) $ (2,559) $ (12,003) $ (25,266) $ (60,225) ​

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Ground Leases 2023 ​ $ 3,110 2024 ​ ​ 12,442 2025 ​ ​ 12,442 2026 ​ ​ 12,442 2027 ​ ​ 12,442 Thereafter ​ ​ 417,895 Total future minimum lease payments (undiscounted) ​ ​ 470,773 Difference between future undiscounted cash flows and discounted cash flows ​ ​ (284,072) Total operating lease liabilities (discounted) ​ $ 186,701
Lessee - components of operating lease expenses	The components of operating lease expenses were as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Lease expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual lease expense ​ $ 3,293 ​ $ 3,226 ​ $ 9,877 ​ $ 9,760 Variable lease expense (a) ​ ​ 42 ​ ​ 28 ​ ​ 103 ​ ​ 81 Total operating lease expense (b)(c) ​ $ 3,335 ​ $ 3,254 ​ $ 9,980 ​ $ 9,841 (a) Variable lease expense includes adjustments such as changes in the consumer price index and payments based on a percentage of a community’s revenue. (b) Lease expense is reported within the line item Other operating expenses on the Consolidated Statements of Operations. (c) For the nine months ended September 30, 2023, Operating lease right-of-use assets and Operating lease liabilities amortized by $2.6 million and $2.5 million, respectively. For the nine months ended September 30, 2022, Operating lease right-of-use assets and Operating lease liabilities amortized by $2.5 million and $2.4 million, respectively. Due to the net impact of the amortization, the Company recorded less than $0.1 million and $0.1 million of total operating lease expense during the three months ended September 30, 2023 and 2022, respectively, and $0.1 million and $0.3 million of total operating lease expense during the nine months ended September 30, 2023 and 2022, respectively.
Lessor - Future minimum lease payments	Future minimum lease payments from our retail and commercial leases as of September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ Retail and Commercial Leases 2023 ​ $ 6,564 2024 ​ ​ 26,561 2025 ​ ​ 23,717 2026 ​ ​ 21,032 2027 ​ ​ 17,155 Thereafter ​ ​ 70,079 Total future minimum lease payments (a) ​ $ 165,108 (a)

SECURED AND UNSECURED DEBT, N_2

SECURED AND UNSECURED DEBT, NET (Tables)	9 Months Ended
	Sep. 30, 2023
Secured and Unsecured Debt
Schedule of debt instruments	The following is a summary of our secured and unsecured debt at September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Principal Outstanding ​ As of September 30, 2023 ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ Average ​ Number of ​ ​ September 30, ​ December 31, ​ Interest ​ Years to ​ Communities ​ 2023 2022 Rate Maturity Encumbered Secured Debt: ​ ​ ​ ​ ​ ​ ​ Fixed Rate Debt ​ ​ Mortgage notes payable (a) ​ $ 1,214,110 ​ $ 1,005,622 3.48 % 4.9 20 Deferred financing costs and other non-cash adjustments (b) ​ (2,823) ​ 19,712 Total fixed rate secured debt, net ​ 1,211,287 ​ 1,025,334 3.48 % 4.9 20 Variable Rate Debt ​ ​ Tax-exempt secured notes payable (c) ​ 27,000 ​ 27,000 4.42 % 8.5 1 Deferred financing costs ​ (47) ​ (53) Total variable rate secured debt, net ​ 26,953 ​ 26,947 4.42 % 8.5 1 Total Secured Debt, net ​ 1,238,240 ​ 1,052,281 3.45 % 5.0 21 Unsecured Debt: ​ ​ Variable Rate Debt ​ ​ Borrowings outstanding under unsecured credit facility due January 2026 (d) (m) ​ — ​ — — % 2.3 Borrowings outstanding under unsecured commercial paper program due October 2023 (e) (m) ​ ​ 380,000 ​ ​ 300,000 ​ 5.59 % 0.1 ​ ​ Borrowings outstanding under unsecured working capital credit facility due January 2024 ​ 26,700 ​ 28,015 6.19 % 0.3 Term Loan due January 2027 (d) (m) ​ — ​ 175,000 — % 3.3 Fixed Rate Debt ​ ​ Term Loan due January 2027 (d) (m) ​ ​ 350,000 ​ 175,000 3.36 % 3.3 ​ ​ 8.50% Debentures due September 2024 ​ 15,644 ​ 15,644 8.50 % 1.0 2.95% Medium-Term Notes due September 2026 (g) (m) ​ 300,000 ​ 300,000 2.89 % 2.9 3.50% Medium-Term Notes due July 2027 (net of discounts of $264 and $317, respectively) (h) (m) ​ ​ 299,736 ​ ​ 299,683 ​ 4.03 % 3.8 ​ ​ 3.50% Medium-Term Notes due January 2028 (net of discounts of $509 and $598, respectively) (m) ​ ​ 299,491 ​ ​ 299,402 ​ 3.50 % 4.3 ​ ​ 4.40% Medium-Term Notes due January 2029 (net of discounts of $3 and $4, respectively) (i) (m) ​ ​ 299,997 ​ ​ 299,996 ​ 4.27 % 5.3 ​ ​ 3.20% Medium-Term Notes due January 2030 (net of premiums of $8,637 and $9,667, respectively) (j) (m) ​ ​ 608,637 ​ ​ 609,667 ​ 3.32 % 6.3 ​ ​ 3.00% Medium-Term Notes due August 2031 (net of premiums of $9,408 and $10,304, respectively) (k) (m) ​ ​ 609,408 ​ ​ 610,304 ​ 3.01 % 7.9 ​ ​ 2.10% Medium-Term Notes due August 2032 (net of discounts of $311 and $338, respectively) (m) ​ ​ 399,689 ​ ​ 399,662 ​ 2.10 % 8.8 ​ ​ 1.90% Medium-Term Notes due March 2033 (net of discounts of $1,140 and $1,230, respectively) (m) ​ ​ 348,860 ​ ​ 348,770 ​ 1.90 % 9.5 ​ ​ 2.10% Medium-Term Notes due June 2033 (net of discounts of $966 and $1,041, respectively) (m) ​ ​ 299,034 ​ ​ 298,959 ​ 2.10 % 9.7 ​ ​ 3.10% Medium-Term Notes due November 2034 (net of discounts of $978 and $1,045, respectively) (l) (m) ​ ​ 299,022 ​ ​ 298,955 ​ 3.13 % 11.1 ​ ​ Other ​ 2 ​ 5 Deferred financing costs ​ (21,638) ​ (24,040) Total Unsecured Debt, net ​ 4,514,582 ​ 4,435,022 3.34 % 6.1 Total Debt, net ​ $ 5,752,822 ​ $ 5,487,303 3.37 % 5.9
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 September 30, 2023 are as follows (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Fixed Total Variable Total Total Total Year ​ Secured Debt ​ Secured Debt ​ Secured Debt ​ Unsecured Debt ​ Debt 2023 ​ $ 359 ​ $ — ​ $ 359 ​ $ 380,000 (a) $ 380,359 2024 ​ ​ 97,578 ​ ​ — ​ ​ 97,578 ​ ​ 42,344 ​ ​ 139,922 2025 ​ 178,568 ​ — ​ 178,568 ​ — ​ 178,568 2026 ​ 56,665 ​ — ​ 56,665 ​ 300,000 ​ 356,665 2027 ​ 6,931 ​ — ​ 6,931 ​ 650,000 ​ 656,931 2028 ​ 166,518 ​ — ​ 166,518 ​ 300,000 ​ 466,518 2029 ​ 315,802 ​ — ​ 315,802 ​ 300,000 ​ 615,802 2030 ​ 230,759 ​ — ​ 230,759 ​ 600,000 ​ 830,759 2031 ​ 160,930 ​ — ​ 160,930 ​ 600,000 ​ 760,930 2032 ​ — ​ 27,000 ​ 27,000 ​ 400,000 ​ 427,000 Thereafter ​ — ​ — ​ — ​ 950,000 ​ 950,000 Subtotal ​ 1,214,110 ​ 27,000 ​ 1,241,110 ​ 4,522,344 ​ 5,763,454 Non-cash (b) ​ (2,823) ​ (47) ​ (2,870) ​ (7,762) ​ (10,632) Total ​ $ 1,211,287 ​ $ 26,953 ​ $ 1,238,240 ​ $ 4,514,582 ​ $ 5,752,822 (a) All unsecured debt due in the remainder of 2023 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 September 30, 2023 and 2022, respectively, and $2.9 million and $2.9 million, respectively, during the nine months ended September 30, 2023 and 2022, of deferred financing costs into Interest expense.
Commercial Paper
Secured and Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the unsecured commercial paper program at September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Total unsecured commercial paper program $ 700,000 ​ $ 700,000 ​ Borrowings outstanding at end of period ​ 380,000 ​ 300,000 ​ Weighted average daily borrowings during the period ended ​ 378,941 ​ 405,671 ​ Maximum daily borrowings during the period ended ​ 505,000 ​ 700,000 ​ Weighted average interest rate during the period ended ​ 5.3 % 2.3 % Interest rate at end of the period ​ 5.6 % 4.7 %
Revolving Credit Facility
Secured and Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the Revolving Credit Facility at September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 2022 ​ Total revolving credit facility ​ $ 1,300,000 ​ $ 1,300,000 ​ Borrowings outstanding at end of period (1) ​ — ​ — ​ Weighted average daily borrowings during the period ended ​ 2,747 ​ 3,776 ​ Maximum daily borrowings during the period ended ​ 250,000 ​ 205,000 ​ Weighted average interest rate during the period ended ​ 5.6 % 3.9 % Interest rate at end of the period ​ — % — % (1) Excludes $2.3 million and $2.6 million of letters of credit at September 30, 2023 and December 31, 2022, respectively .
Working capital credit facility
Secured and Unsecured Debt
Schedule of short-term debt	The following is a summary of short-term bank borrowings under the Working Capital Credit Facility at September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Total working capital credit facility ​ $ 75,000 ​ $ 75,000 ​ Borrowings outstanding at end of period ​ 26,700 ​ 28,015 ​ Weighted average daily borrowings during the period ended ​ 16,920 ​ 15,080 ​ Maximum daily borrowings during the period ended ​ 57,107 ​ 55,812 ​ Weighted average interest rate during the period ended ​ 5.8 % 3.0 % Interest rate at end of the period ​ 6.2 % 5.2 %

INCOME_(LOSS) PER SHARE (Tables

INCOME/(LOSS) PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2023
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 ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 ​ Numerator for income/(loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income/(loss) ​ $ 35,419 ​ $ 25,145 ​ $ 438,527 ​ $ 45,112 ​ Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (2,554) ​ (1,533) ​ (27,137) ​ (2,684) ​ Net (income)/loss attributable to noncontrolling interests ​ (7) ​ (7) ​ (23) ​ (34) ​ Net income/(loss) attributable to UDR, Inc. ​ 32,858 ​ 23,605 ​ 411,367 ​ 42,394 ​ Distributions to preferred stockholders — Series E (Convertible) ​ (1,221) ​ (1,106) ​ (3,626) ​ (3,307) ​ Income/(loss) attributable to common stockholders - basic and diluted ​ ​ 31,637 ​ ​ 22,499 ​ ​ 407,741 ​ ​ 39,087 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for income/(loss) per share: ​ ​ ​ ​ ​ Weighted average common shares outstanding ​ 329,130 ​ 324,983 ​ 329,207 ​ 320,654 ​ Non-vested restricted stock awards ​ (370) ​ (282) ​ (372) ​ (276) ​ Denominator for basic income/(loss) per share ​ 328,760 ​ 324,701 ​ 328,835 ​ 320,378 ​ Incremental shares issuable from assumed conversion of unvested LTIP Units, performance units, unvested restricted stock and shares issuable upon settlement of forward sales agreements ​ 441 ​ 985 ​ 448 ​ 1,251 ​ Denominator for diluted income/(loss) per share ​ 329,201 ​ 325,686 ​ 329,283 ​ 321,629 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income/(loss) per weighted average common share: ​ ​ ​ ​ ​ Basic ​ $ 0.10 ​ $ 0.07 ​ $ 1.24 ​ $ 0.12 ​ Diluted ​ $ 0.10 ​ $ 0.07 ​ $ 1.24 ​ $ 0.12 ​
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table sets forth the additional shares of common stock outstanding, by equity instrument, if converted to common stock for each of the three and nine months ended September 30, 2023 and 2022 (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ OP/DownREIT Units 22,511 21,474 21,699 21,514 Convertible preferred stock 2,908 2,918 2,908 2,918 Unvested LTIP Units and unvested restricted stock 441 985 448 1,251 ​

NONCONTROLLING INTERESTS (Table

NONCONTROLLING INTERESTS (Tables)	9 Months Ended
	Sep. 30, 2023
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 at December 31, 2022 $ 839,850 ​ Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (65,799) ​ OP Units issued for real estate, net ​ 141,359 ​ Conversion of OP Units/DownREIT Units to Common Stock or Cash ​ (26,537) ​ Net income/(loss) attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ 27,137 ​ Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (29,203) ​ Redeemable Long-Term and Short-Term Incentive Plan Units ​ ​ 20,474 ​ Allocation of other comprehensive income/(loss) ​ (12) ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership at September 30, 2023 ​ $ 907,269 ​

FAIR VALUE OF DERIVATIVES AND_2

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 and December 31, 2022, are summarized as follows (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at September 30, 2023, 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 ​ ​ September 30, ​ September 30, ​ Liabilities ​ Inputs ​ Inputs ​ ​ 2023 (a) ​ 2023 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable, net (b) ​ $ 209,297 ​ $ 211,278 ​ $ — ​ $ — ​ $ 211,278 Equity securities (c) ​ ​ 17,780 ​ ​ 17,780 ​ ​ 17,780 ​ ​ — ​ ​ — Derivatives - Interest rate contracts (d) ​ 14,150 ​ 14,150 ​ — ​ 14,150 ​ — Total assets ​ $ 241,227 ​ $ 243,208 ​ $ 17,780 ​ $ 14,150 ​ $ 211,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (e) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 1,215,988 ​ $ 1,078,613 ​ $ — ​ $ — ​ $ 1,078,613 Secured debt instruments - variable rate: (e) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (e) ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 26,700 ​ ​ 26,700 ​ ​ — ​ ​ — ​ ​ 26,700 Commercial paper program ​ ​ 380,000 ​ ​ 380,000 ​ ​ — ​ ​ — ​ ​ 380,000 Unsecured notes ​ ​ 4,129,520 ​ ​ 3,418,985 ​ ​ — ​ ​ — ​ ​ 3,418,985 Total liabilities ​ $ 5,779,208 ​ $ 4,931,298 ​ $ — ​ $ — ​ $ 4,931,298 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (f) ​ $ 907,269 ​ $ 907,269 ​ $ — ​ $ 907,269 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value at December 31, 2022, 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 ​ 2022 (a) ​ 2022 ​ (Level 1) ​ (Level 2) ​ (Level 3) Description: ​ ​ ​ ​ ​ ​ Notes receivable, net (b) ​ $ 54,707 ​ $ 55,514 ​ $ — ​ $ — ​ $ 55,514 Equity securities (c) ​ ​ 9,707 ​ ​ 9,707 ​ ​ 9,707 ​ ​ — ​ ​ — Derivatives - Interest rate contracts (d) ​ 15,270 ​ 15,270 ​ — ​ 15,270 ​ — Total assets ​ $ 79,684 ​ $ 80,491 ​ $ 9,707 ​ $ 15,270 ​ $ 55,514 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Secured debt instruments - fixed rate: (e) ​ ​ ​ ​ ​ ​ Mortgage notes payable ​ $ 1,028,169 ​ $ 909,041 ​ $ — ​ $ — ​ $ 909,041 Secured debt instruments - variable rate: (e) ​ ​ ​ ​ ​ ​ Tax-exempt secured notes payable ​ 27,000 ​ 27,000 ​ — ​ — ​ 27,000 Unsecured debt instruments: (e) ​ ​ ​ ​ ​ ​ ​ Working capital credit facility ​ ​ 28,015 ​ ​ 28,015 ​ ​ — ​ ​ — ​ ​ 28,015 Commercial paper program ​ ​ 300,000 ​ ​ 300,000 ​ ​ — ​ ​ — ​ ​ 300,000 Unsecured notes ​ ​ 4,131,047 ​ ​ 3,448,632 ​ ​ — ​ ​ — ​ ​ 3,448,632 Total liabilities ​ $ 5,514,231 ​ $ 4,712,688 ​ $ — ​ $ — ​ $ 4,712,688 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership (f) ​ $ 839,850 ​ $ 839,850 ​ $ — ​ $ 839,850 ​ $ — (a) Certain balances include fair market value adjustments and exclude deferred financing costs. (b) See Note 2, Significant Accounting Policies . (c) The Company holds a direct investment in a publicly traded real estate technology company, SmartRent. The investment is valued at the market price on September 30, 2023 and December 31, 2022. The Company currently classifies the investment as Level 1 in the fair value hierarchy. During the nine months ended September 30, 2023, the Company increased its direct investment in SmartRent due to stock distributions from its unconsolidated real estate technology investments. (d) See Note 11, Derivatives and Hedging Activity . (e) See Note 7, Secured and Unsecured Debt, Net . (f) See Note 9, Noncontrolling Interests.

DERIVATIVES AND HEDGING ACTIV_2

DERIVATIVES AND HEDGING ACTIVITY (Tables)	9 Months Ended
	Sep. 30, 2023
DERIVATIVES AND HEDGING ACTIVITY
Schedule of outstanding interest rate derivatives	As of September 30, 2023, 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 and caps ​ 6 ​ $ 369,880 ​
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 September 30, 2023 and December 31, 2022 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset Derivatives ​ Liability Derivatives ​ ​ (included in Other assets ) ​ (included in Other liabilities ) ​ ​ Fair Value at: ​ Fair Value at: ​ ​ September 30, ​ December 31, ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Derivatives designated as hedging instruments: ​ ​ ​ ​ Interest rate products ​ $ 14,150 ​ $ 15,270 ​ $ — ​ $ —
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 and nine months ended September 30, 2023 and 2022 ( 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 2023 2022 2023 2022 2023 2022 Three Months Ended September 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ 1,314 ​ $ 5,048 ​ $ 2,110 ​ $ 313 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate products ​ $ 5,336 ​ $ 13,988 ​ $ 5,332 ​ $ 28 ​ $ — ​ $ —
Effect of Company's derivatives not designated as hedging instruments on the Consolidated Statements of Operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 Total amount of Interest expense ​ $ 44,664 ​ $ 39,905 ​ $ 133,519 ​ $ 112,653
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 September 30, 2023 and December 31, 2022 (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Net Amounts of Gross Amounts Not Offset ​ ​ ​ ​ ​ ​ ​ ​ Amounts ​ Assets ​ in the Consolidated ​ ​ ​ ​ ​ Gross ​ Offset in the ​ Presented in the ​ Balance Sheets ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Assets ​ Assets ​ Sheets ​ (a) ​ Instruments Received Net Amount September 30, 2023 ​ $ 14,150 ​ $ — ​ $ 14,150 ​ $ — ​ $ — ​ $ 14,150 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ $ 15,270 ​ $ — ​ $ 15,270 ​ $ — ​ $ — ​ $ 15,270 (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 Sheets ​ ​ ​ ​ ​ Amounts of ​ Consolidated ​ Consolidated ​ ​ ​ ​ Cash ​ ​ ​ ​ ​ Recognized ​ Balance ​ Balance Sheets ​ Financial ​ Collateral ​ ​ ​ Offsetting of Derivative Liabilities Liabilities Sheets (a) Instruments Posted Net Amount September 30, 2023 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — (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)	9 Months Ended
	Sep. 30, 2023
COMMITMENTS AND CONTINGENCIES
Summary of real estate commitments	The following summarizes the Company’s commitments at September 30, 2023 ( dollars in thousands ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ UDR's ​ UDR's Remaining ​ ​ ​ Properties ​ Investment (a) ​ Commitment ​ Real estate commitments ​ ​ ​ ​ ​ ​ ​ ​ ​ Wholly-owned — under development 2 ​ $ 139,143 ​ $ 48,357 Wholly-owned — redevelopment (b) 8 ​ ​ 35,253 ​ ​ 69,747 Other unconsolidated investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate technology investments (c) ​ - ​ ​ 50,931 ​ ​ 45,069 ​ Total ​ $ 225,327 ​ $ 163,173 (a) Represents UDR’s investment as of September 30, 2023. (b) Projects consist of unit renovations and/or renovation of related common area amenities. (c) As of September 30, 2023, the investments were recorded in either Investment in and advances to unconsolidated joint ventures, net or Other Assets on the Consolidated Balance Sheets .

REPORTABLE SEGMENTS (Tables)

REPORTABLE SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2023
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 and nine months ended September 30, 2023 and 2022, and reconciles NOI to Net income/(loss) attributable to UDR, Inc. (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, (a) ​ September 30, (b) ​ 2023 2022 2023 2022 Reportable apartment home segment lease revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 119,203 ​ $ 114,322 ​ $ 351,822 ​ $ 334,229 Mid-Atlantic Region ​ 78,462 ​ 74,999 ​ 231,564 ​ 219,043 Northeast Region ​ 79,958 ​ 74,857 ​ 225,868 ​ 208,950 Southeast Region ​ 57,035 ​ 53,811 ​ 169,613 ​ 154,306 Southwest Region ​ 37,872 ​ 36,801 ​ 113,139 ​ 106,220 Non-Mature Communities/Other ​ 22,364 ​ 22,057 ​ 80,536 ​ 55,613 Total segment and consolidated lease revenue ​ $ 394,894 ​ $ 376,847 ​ $ 1,172,542 ​ $ 1,078,361 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment other revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 3,106 ​ $ 3,220 ​ $ 8,837 ​ $ 9,059 Mid-Atlantic Region ​ 3,436 ​ 3,149 ​ 8,884 ​ 8,534 Northeast Region ​ 2,095 ​ 2,295 ​ 5,282 ​ 5,232 Southeast Region ​ 2,571 ​ 2,245 ​ 7,030 ​ 6,576 Southwest Region ​ 1,813 ​ 1,647 ​ 4,795 ​ 4,337 Non-Mature Communities/Other ​ 444 ​ 620 ​ 2,394 ​ 1,853 Total segment and consolidated other revenue ​ $ 13,465 ​ $ 13,176 ​ $ 37,222 ​ $ 35,591 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total reportable apartment home segment rental income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ ​ West Region ​ $ 122,309 ​ $ 117,542 ​ $ 360,659 ​ $ 343,288 Mid-Atlantic Region ​ 81,898 ​ 78,148 ​ 240,448 ​ 227,577 Northeast Region ​ 82,053 ​ 77,152 ​ 231,150 ​ 214,182 Southeast Region ​ 59,606 ​ 56,056 ​ 176,643 ​ 160,882 Southwest Region ​ 39,685 ​ 38,448 ​ 117,934 ​ 110,557 Non-Mature Communities/Other ​ 22,808 ​ 22,677 ​ 82,930 ​ 57,466 Total segment and consolidated rental income ​ $ 408,359 ​ $ 390,023 ​ $ 1,209,764 ​ $ 1,113,952 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reportable apartment home segment NOI ​ ​ ​ ​ Same-Store Communities ​ ​ ​ ​ West Region ​ $ 90,574 ​ $ 87,095 ​ $ 269,108 ​ $ 256,265 Mid-Atlantic Region ​ 55,921 ​ 53,317 ​ 165,552 ​ 156,286 Northeast Region ​ 53,392 ​ 49,990 ​ 152,212 ​ 139,301 Southeast Region ​ 40,667 ​ 37,854 ​ 121,018 ​ 108,904 Southwest Region ​ 25,587 ​ 23,611 ​ 75,449 ​ 69,356 Non-Mature Communities/Other ​ 12,515 ​ 13,151 ​ 47,541 ​ 33,394 Total segment and consolidated NOI ​ 278,656 ​ 265,018 ​ 830,880 ​ 763,506 Reconciling items: ​ ​ ​ ​ Joint venture management and other fees ​ 1,772 ​ 1,274 ​ 4,464 ​ 3,778 Property management ​ (13,271) ​ (12,675) ​ (39,317) ​ (36,203) Other operating expenses ​ (4,611) ​ (3,746) ​ (11,902) ​ (13,485) Real estate depreciation and amortization ​ (167,551) ​ (166,781) ​ (505,776) ​ (497,987) General and administrative ​ (15,159) ​ (15,840) ​ (49,091) ​ (47,333) Casualty-related (charges)/recoveries, net ​ 1,928 ​ (901) ​ (3,362) ​ (1,210) Other depreciation and amortization ​ (3,692) ​ (3,430) ​ (11,022) ​ (9,521) Gain/(loss) on sale of real estate owned ​ ​ — ​ ​ — ​ ​ 325,885 ​ ​ — Income/(loss) from unconsolidated entities ​ 5,508 ​ 10,003 ​ 24,912 ​ 4,186 Interest expense ​ (44,664) ​ (39,905) ​ (133,519) ​ (112,653) Interest income and other income/(expense), net ​ (3,069) ​ (7,495) ​ 8,388 ​ (6,934) Tax (provision)/benefit, net ​ (428) ​ (377) ​ (2,013) ​ (1,032) Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership ​ (2,554) ​ (1,533) ​ (27,137) ​ (2,684) Net (income)/loss attributable to noncontrolling interests ​ (7) ​ (7) ​ (23) ​ (34) Net income/(loss) attributable to UDR, Inc. ​ $ 32,858 ​ $ 23,605 ​ $ 411,367 ​ $ 42,394 (a) Same-Store Community population consisted of 52,291 apartment homes. (b) Same-Store Community population consisted of 51,858 apartment homes. ​
Details of assets of UDR's reportable segments	The following table details the assets of UDR’s reportable segments as of September 30, 2023 and December 31, 2022 (dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2023 ​ 2022 Reportable apartment home segment assets: ​ ​ Same-Store Communities (a): ​ ​ West Region ​ $ 4,415,840 ​ $ 4,363,452 Mid-Atlantic Region ​ 3,295,218 ​ 3,245,297 Northeast Region ​ 3,876,325 ​ 3,834,761 Southeast Region ​ 1,572,392 ​ 1,521,489 Southwest Region ​ 1,319,617 ​ 1,287,332 Non-Mature Communities/Other ​ 1,439,232 ​ 1,317,741 Total segment assets ​ 15,918,624 ​ 15,570,072 Accumulated depreciation ​ (6,117,312) ​ (5,762,501) Total segment assets — net book value ​ 9,801,312 ​ 9,807,571 Reconciling items: ​ ​ Cash and cash equivalents ​ 1,624 ​ 1,193 Restricted cash ​ 30,831 ​ 29,001 Notes receivable, net ​ 209,297 ​ 54,707 Investment in and advances to unconsolidated joint ventures, net ​ 963,927 ​ 754,446 Operating lease right-of-use assets ​ ​ 191,499 ​ ​ 194,081 Other assets ​ 221,572 ​ 197,471 Total consolidated assets ​ $ 11,420,062 ​ $ 11,038,470 (a) Same-Store Community population consisted of 52,291 apartment homes. ​

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) shares in Millions	9 Months Ended
	Sep. 30, 2023 home community item shares
Consolidation And Basis Of Presentation
Number of Real Estate Properties | community	168
Number of Markets Operating Within | item	21
Number Of Apartment Homes Owned And Consolidated By Company | home	55,597
Joint venture, number of completed or to be completed homes in communities | home	9,956
Preferred equity investment,, number of apartment homes | home	5,791
Operating Partnership outstanding units	189.9
United Dominion Reality L.P.
Consolidation And Basis Of Presentation
Operating Partnership units outstanding related to limited partner	176.4
General Partnership units outstanding	0.1
General Partners' ownership (as a percent)	92.90%
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	13.5
Percentage of units outstanding in Partnership	7.10%
Non-affiliated Partners | UDR Lighthouse DownREIT L.P.
Consolidation And Basis Of Presentation
Operating Partnership outstanding units	11.1
Percentage of units outstanding in Partnership	34.30%
UDR, Inc.
Consolidation And Basis Of Presentation
General Partners' ownership (as a percent)	65.70%
Operating Partnership outstanding units	21.3

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Significant Accounting Policies
Credit losses	$ (100)	$ (100)	$ (600)	$ (100)
Allocation of other comprehensive income/(loss)			(12)
Current income tax expense (benefit)			0
Net deferred tax assets/(liabilities)	(800)		(800)		$ (800)
Non-related party
Significant Accounting Policies
Interest income	5,000	1,000	8,400	2,400
Related party
Significant Accounting Policies
Interest income			0	0
Noncontrolling Interest
Significant Accounting Policies
Allocation of other comprehensive income/(loss)		$ 300		$ 900
Maximum | Noncontrolling Interest
Significant Accounting Policies
Allocation of other comprehensive income/(loss)	(100)		(100)
Multifamily tenant lease
Significant Accounting Policies
Tenant leases receivable, net	9,200		9,200
Retail tenant lease
Significant Accounting Policies
Tenant leases receivable, net	$ 300		$ 300

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES - Notes Receivables (Details) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2023 USD ($) home item	Sep. 30, 2023 USD ($) home item	Oct. 31, 2023	May 31, 2023	Dec. 31, 2022 USD ($)
Accounting Policies [Line Items]
Notes receivable		$ 210,201			$ 54,982
Allowance for credit losses		(904)			(275)
Notes receivable, net		209,297			54,707
Note due October 2024
Accounting Policies [Line Items]
Notes receivable		$ 95,734
Note receivable interest rate	9.50%	9.50%	10.50%	8.50%
Number of apartment homes | home	471
Aggregate commitment funded on note receivable	$ 20,000
Number of extension options | item	3
Term of notes receivable extension options	1 year
Note due December 2024
Accounting Policies [Line Items]
Notes receivable		$ 35,309			$ 30,377
Note receivable interest rate		12%			10%
Aggregate commitment on note receivable		$ 32,500			$ 31,400
Aggregate commitment funded on note receivable		30,900
Accrued interest added to principal balance		4,400
Note maturity public capital threshold		5,000
Note due December 2026. | Home Community, Riverside, California
Accounting Policies [Line Items]
Notes receivable		$ 51,309			17,292
Note receivable interest rate		11%
Number of apartment homes | home		482
Aggregate commitment on note receivable		$ 59,700
Aggregate commitment funded on note receivable		$ 30,700
Interest payment accrual		36 months
Number of extension options | item		2
Term of notes receivable extension options		1 year
Note due December 2026. | Home Community, Menifee, California
Accounting Policies [Line Items]
Number of apartment homes | home		237
Aggregate commitment on note receivable		$ 24,400
Aggregate commitment funded on note receivable		$ 17,500
Interest payment accrual		36 months
Number of extension options | item		2
Term of notes receivable extension options		1 year
Note due December 2026 | Home Community, Menifee, California
Accounting Policies [Line Items]
Notes receivable		$ 24,276			5,813
Note receivable interest rate		11%
Note due June 2027
Accounting Policies [Line Items]
Notes receivable		$ 3,573			1,500
Note receivable interest rate		18%
Aggregate commitment on note receivable		$ 3,000
Increase in Aggregate Commitment on Note Receivable		1,500
Total revolving credit facility		$ 19,000			$ 16,000

REAL ESTATE OWNED - Summarizes

REAL ESTATE OWNED - Summarizes the carrying amounts for our real estate owned (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Real estate owned
Land	$ 2,558,608	$ 2,539,499
Depreciable property - held and used:
Land improvements	250,623	254,578
Building, improvements, and furniture, fixtures and equipment	12,920,237	12,521,838
Real estate intangible assets	50,013	50,013
Under development:
Real estate under development	139,143	189,809
Real estate owned	15,918,624	15,570,072
Accumulated depreciation	(6,117,312)	(5,762,501)
Total real estate owned, net of accumulated depreciation	9,801,312	9,807,571
Accumulated amortization	16,200	13,100
Land and land improvements
Under development:
Real estate under development	16,576	43,711
Building, improvements and furniture, fixtures and equipment
Under development:
Real estate under development	$ 122,567	146,394
Real estate assets held for sale		$ 14,039

REAL ESTATE OWNED - Additional

REAL ESTATE OWNED - Additional Information (Details) $ in Thousands, shares in Millions	1 Months Ended				3 Months Ended		9 Months Ended
	Aug. 31, 2023 USD ($) home community loan shares	Jun. 30, 2023 USD ($) home community	Feb. 28, 2023 home	Jan. 31, 2023 USD ($)	Sep. 30, 2023 USD ($) community home state	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) community home state	Sep. 30, 2022 USD ($)
Real Estate Owned Disclosure
Number of real estate properties | community					168		168
Number of states in which there are owned and consolidated communities | state					13		13
Number of apartment homes owned and consolidated | home					55,597		55,597
Long-term Debt					$ 5,763,454		$ 5,763,454
Gain/(loss) on sale of real estate owned					0	$ 0	325,885	$ 0
Development costs excluding direct costs and capitalized interest					2,600	5,200	10,300	15,400
Capitalized interest during period					$ 2,600	$ 3,500	$ 7,200	$ 10,400
Retail Component of Development Community Located in Washington D.C. | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Real Estate Owned Disclosure
Proceeds from sale of real estate				$ 14,400
Maximum | Retail Component of Development Community Located in Washington D.C. | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Real Estate Owned Disclosure
Gain/(loss) on sale of real estate owned				$ 100
Four Wholly-Owned Operating Communities
Real Estate Owned Disclosure
UDR's Ownership Interest		51%
HQ
Real Estate Owned Disclosure
Number of apartment homes acquired | home			136
Texas Operating Communities
Real Estate Owned Disclosure
Number of apartment homes acquired | home	1,753
Number of communities acquired | community	6
Real estate acquired, Purchase price	$ 354,600
Number of mortgage loans acquired | loan	6
Number of community issued (in shares) | shares	3.6
Number of valued	$ 141,400
Increase from acquisition	344,800
Real estate in-place lease intangibles	9,800
Debt discount	$ 17,600
Texas Operating Communities | Mortgages loans
Real Estate Owned Disclosure
Number of communities acquired | community	6
Number of mortgage loans acquired | loan	6
Long-term Debt	$ 209,400
Long term debt fair value	191,700
Texas Operating Communities | Mortgages loans | Minimum
Real Estate Owned Disclosure
Long-term Debt	28,000
Texas Operating Communities | Mortgages loans | Maximum
Real Estate Owned Disclosure
Long-term Debt	$ 40,000
Property in Dallas, Texas
Real Estate Owned Disclosure
Number of communities acquired | community	4
Property in Austin, Texas
Real Estate Owned Disclosure
Number of communities acquired | community	2
Four Wholly-Owned Operating Communities
Real Estate Owned Disclosure
Proceeds from sale of real estate		$ 247,900
Number of wholly owned communities contributed | community		4
Number of apartment homes contributed | home		1,328
Gain/(loss) on sale of real estate owned		$ 325,900

JOINT VENTURES AND PARTNERSHI_3

JOINT VENTURES AND PARTNERSHIPS - Summary (Details)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($) community agreement	Sep. 30, 2023 USD ($) property home community	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) property home item community agreement	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Unconsolidated entities
Number of communities | community		168		168
Total assets		$ 11,420,062,000		$ 11,420,062,000		$ 11,038,470,000
Total liabilities		6,361,659,000		6,361,659,000		6,100,325,000
Investment in unconsolidated entities		955,216,000		955,216,000		746,994,000
Income/(loss) from investments		5,508,000	$ 10,003,000	24,912,000	$ 4,186,000
Sold joint ventures and other investments		$ (16,000)	6,615,000	$ 3,140,000	21,278,000	70,501,000
Number of preferred equity investment agreement amended to be inclusive of accrued preferred return | agreement				1
UDR/MetLife
Unconsolidated entities
Number of communities | property		13		13
Number of apartment homes | home		2,837		2,837
Investment in unconsolidated entities		$ 231,240,000		$ 231,240,000		$ 247,160,000
UDR's Ownership Interest		50.10%		50.10%		50.10%
Income/(loss) from investments		$ (1,455,000)	(1,827,000)	$ (3,930,000)	(6,266,000)
UDR/LaSalle
Unconsolidated entities
Number of communities | property		4		4
Number of apartment homes | home		1,328		1,328
Number of wholly owned communities contributed | community	4
Proceeds from Sale of Real Estate	$ 247,900,000
Investment in unconsolidated entities	$ 258,200,000	$ 255,181,000		$ 255,181,000
UDR's Ownership Interest		51%		51%
Income/(loss) from investments		$ (1,647,000)		$ (1,689,000)
Preferred Equity Investments
Unconsolidated entities
Number of communities | community		24		24
Number of apartment homes		5,791		5,791
Weighted Average Rate		9.50%		9.50%
Investment in unconsolidated entities		$ 429,031,000		$ 429,031,000		$ 390,086,000
Income/(loss) from investments		8,211,000	6,660,000	$ 26,857,000	17,973,000
Years to Maturity				3 years 1 month 6 days
UDR Commitment		$ 365,384,000		$ 365,384,000
Number of investments which receive a variable percentage of the value created from the project upon a capital or liquidating event | item				5
Unconsolidated Joint Ventures
Unconsolidated entities
Number of communities | property		17		17
Number of apartment homes | home		4,165		4,165
Investment in unconsolidated entities		$ 486,421,000		$ 486,421,000		247,160,000
Income/(loss) from investments		$ (3,102,000)	(1,827,000)	$ (5,619,000)	(6,266,000)
Variable Interest Entity, Primary Beneficiary
Unconsolidated entities
Number of apartment homes | home		136		136
Operating Community | Preferred Equity Investments
Unconsolidated entities
Number of communities | community		22		22
Number of apartment homes		4,718		4,718
Weighted Average Rate		9.30%		9.30%
Investment in unconsolidated entities		$ 348,171,000		$ 348,171,000		315,438,000
Income/(loss) from investments		6,059,000	4,751,000	$ 20,643,000	13,783,000
Years to Maturity				3 years 1 month 6 days
UDR Commitment		$ 297,177,000		$ 297,177,000
Number of preferred equity investment agreements amended | agreement	2
Operating Community | Joint venture one
Unconsolidated entities
Incremental funded amount	$ 17,000,000
Operating Community | Joint venture two
Unconsolidated entities
Incremental funded amount	$ 1,800,000
Development Community | Preferred Equity Investments
Unconsolidated entities
Number of communities | community		2		2
Number of apartment homes		1,073		1,073
Weighted Average Rate		10.70%		10.70%
Investment in unconsolidated entities		$ 80,860,000		$ 80,860,000		74,648,000
Income/(loss) from investments		2,152,000	1,909,000	$ 6,214,000	4,190,000
Years to Maturity				3 years 4 months 24 days
UDR Commitment		68,207,000		$ 68,207,000
Development Community | Real estate technology investments RETV I
Unconsolidated entities
Investment in unconsolidated entities		10,360,000		10,360,000		16,601,000
Income/(loss) from investments		(876,000)	(1,458,000)	(101,000)	(28,009,000)
UDR Commitment		18,000,000		18,000,000
Development Community | Real estate technology investments RETV II
Unconsolidated entities
Investment in unconsolidated entities		14,222,000		14,222,000		11,670,000
Income/(loss) from investments		1,547,000	122,000	1,116,000	(603,000)
UDR Commitment		18,000,000		18,000,000
Development Community | Real estate technology investments RETV III
Unconsolidated entities
Investment in unconsolidated entities		1,423,000		1,423,000
Income/(loss) from investments		(117,000)		(117,000)
UDR Commitment		15,000,000		15,000,000
Development Community | Real estate technology investments RET Strategic Fund
Unconsolidated entities
Investment in unconsolidated entities		11,040,000		11,040,000		8,078,000
Income/(loss) from investments		(87,000)	(37,000)	(183,000)	(115,000)
UDR Commitment		25,000,000		25,000,000
Development Community | Real estate technology investments RET ESG
Unconsolidated entities
Investment in unconsolidated entities		2,719,000		2,719,000		2,898,000
Income/(loss) from investments		(52,000)	(72,000)	(181,000)	(72,000)
UDR Commitment		10,000,000		10,000,000
Development Community | Preferred Equity Investments and Real Estate Technology Investments
Unconsolidated entities
Investment in unconsolidated entities		468,795,000		468,795,000		$ 429,333,000
Income/(loss) from investments		$ 8,626,000	$ 5,215,000	$ 27,391,000	$ (10,826,000)
Four Wholly-Owned Operating Communities
Unconsolidated entities
Number of wholly owned communities contributed | community	4
Proceeds from Sale of Real Estate	$ 247,900,000

JOINT VENTURES AND PARTNERSHI_4

JOINT VENTURES AND PARTNERSHIPS - Commitments (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) home item	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) home item	Sep. 30, 2022 USD ($) item	Dec. 31, 2022 USD ($)
Joint Ventures
Investment in unconsolidated entities	$ 955,216,000		$ 955,216,000		$ 746,994,000
Number of Markets Operating Within | item	21		21
Income/(loss) from investments	$ 5,508,000	$ 10,003,000	$ 24,912,000	$ 4,186,000
Gain/(loss) on sale of real estate owned	0	0	325,885,000	0
Deferred fees from the sale of properties	7,600,000		7,600,000		8,100,000
Joint venture management and other fees	$ 1,772,000	$ 1,274,000	$ 4,464,000	$ 3,778,000
Type of revenue	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
Variable Interest Entity, Primary Beneficiary
Joint Ventures
Number of apartment homes | home	136		136
Preferred Equity Investments
Joint Ventures
Investment in unconsolidated entities	$ 429,031,000		$ 429,031,000		390,086,000
Income/(loss) from investments	$ 8,211,000	$ 6,660,000	$ 26,857,000	$ 17,973,000
Number of apartment homes	5,791		5,791
Preferred return (as a percent)	9.50%		9.50%
Commitment	$ 365,384,000		$ 365,384,000
Number of investments which receive a variable percentage of the value created from the project upon a capital or liquidating event | item			5
Preferred Equity Investments | Operating Community
Joint Ventures
Investment in unconsolidated entities	348,171,000		$ 348,171,000		315,438,000
Income/(loss) from investments	$ 6,059,000	4,751,000	$ 20,643,000	13,783,000
Number of apartment homes	4,718		4,718
Preferred return (as a percent)	9.30%		9.30%
Commitment	$ 297,177,000		$ 297,177,000
Preferred Equity Investments | Development Community
Joint Ventures
Investment in unconsolidated entities	80,860,000		80,860,000		74,648,000
Income/(loss) from investments	$ 2,152,000	1,909,000	$ 6,214,000	4,190,000
Number of apartment homes	1,073		1,073
Preferred return (as a percent)	10.70%		10.70%
Commitment	$ 68,207,000		$ 68,207,000
Unconsolidated Joint Ventures
Joint Ventures
Investment in unconsolidated entities	486,421,000		486,421,000		247,160,000
Income/(loss) from investments	$ (3,102,000)	(1,827,000)	$ (5,619,000)	(6,266,000)
Number of apartment homes | home	4,165		4,165
Real estate technology investments RETV I | Development Community
Joint Ventures
Investment in unconsolidated entities	$ 10,360,000		$ 10,360,000		16,601,000
Income/(loss) from investments	(876,000)	(1,458,000)	(101,000)	$ (28,009,000)
Commitment	18,000,000		$ 18,000,000
Number of investments generating unrealized gains/(losses) | item			1	1
Real estate technology investments RETV II | Development Community
Joint Ventures
Investment in unconsolidated entities	14,222,000		$ 14,222,000		11,670,000
Income/(loss) from investments	1,547,000	122,000	1,116,000	$ (603,000)
Commitment	18,000,000		18,000,000
Real estate technology investments RET ESG | Development Community
Joint Ventures
Investment in unconsolidated entities	2,719,000		2,719,000		2,898,000
Income/(loss) from investments	(52,000)	(72,000)	(181,000)	(72,000)
Commitment	10,000,000		10,000,000
Real estate technology investments RET Strategic Fund | Development Community
Joint Ventures
Investment in unconsolidated entities	11,040,000		11,040,000		8,078,000
Income/(loss) from investments	(87,000)	(37,000)	(183,000)	(115,000)
Commitment	25,000,000		25,000,000
Preferred Equity Investments and Real Estate Technology Investments | Development Community
Joint Ventures
Investment in unconsolidated entities	468,795,000		468,795,000		429,333,000
Income/(loss) from investments	8,626,000	$ 5,215,000	27,391,000	$ (10,826,000)
Accounts Payable, Accrued Expenses and Other Liabilities | 13th and Market Properties LLC
Joint Ventures
Investment in unconsolidated entities	$ (8,700,000)		$ (8,700,000)		$ (7,500,000)

JOINT VENTURES AND PARTNERSHI_5

JOINT VENTURES AND PARTNERSHIPS - Combined summary information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	$ 9,801,312		$ 9,801,312			$ 9,807,571
Investments, at fair value	963,927		963,927			754,446
Cash and cash equivalents	1,624	$ 1,532	1,624	$ 1,532		1,193		$ 967
Other Assets	221,572		221,572			197,471
Total assets	11,420,062		11,420,062			11,038,470
Accounts payable, accrued expenses, and other liabilities	125,979		125,979			153,220
Total liabilities	6,361,659		6,361,659			6,100,325
Total equity	4,151,134	3,950,968	4,151,134	3,950,968	$ 4,120,173	4,098,295	$ 3,869,634	$ 3,474,304
Financial information relating to unconsolidated joint ventures operations
Total revenues	410,131	391,297	1,214,228	1,117,730
Property operating expenses	71,599	66,769	205,294	185,658
Real estate depreciation and amortization	167,551	166,781	505,776	497,987
Gain/(loss) on sale of property	0	0	325,885	0
Operating income	78,072	62,919	540,759	161,545
Interest expense	(44,664)	(39,905)	(133,519)	(112,653)
Other income/(loss)	(3,069)	(7,495)	8,388	(6,934)
Net income/(loss)	35,419	25,145	438,527	45,112
Unconsolidated Joint Ventures and Partnerships
Combined summary of balance sheets relating to unconsolidated joint ventures
Total real estate, net	3,131,728		3,131,728			2,739,784
Investments, at fair value	234,081		234,081			213,743
Cash and cash equivalents	78,614		78,614			38,999
Other Assets	148,478		148,478			121,759
Total assets	3,592,901		3,592,901			3,114,285
Third party debt, net	1,966,904		1,966,904			1,937,329
Accounts payable, accrued expenses, and other liabilities	166,978		166,978			217,148
Total liabilities	2,133,882		2,133,882			2,154,477
Total equity	1,459,019		1,459,019			$ 959,808
Financial information relating to unconsolidated joint ventures operations
Total revenues	70,375	38,093	194,752	110,451
Property operating expenses	32,268	18,326	86,779	52,805
Real estate depreciation and amortization	34,874	16,233	84,907	50,689
Gain/(loss) on sale of property				127,542
Operating income	3,233	3,534	23,066	134,499
Interest expense	(18,138)	(9,829)	(65,202)	(26,598)
Net unrealized/realized gain/(loss) on held investments		19,331	38,863	95,953
Net realized gain/(loss) on held investments	13,580	(24,561)	(21,757)	(263,202)
Other income/(loss)	(1,234)	(478)	(236)	(877)
Net income/(loss)	$ (2,559)	$ (12,003)	$ (25,266)	$ (60,225)

LEASES - Lessee Future Minimum

LEASES - Lessee Future Minimum Payments (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($) community	Dec. 31, 2022 USD ($)
Lease expense:
Number of communities subject to ground leases | community	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 191,499	$ 194,081
Weighted average remaining lease term	42 years 1 month 6 days	42 years 7 months 6 days
Weighted average discount rate	5%	5%
Future minimum lease payments
Total operating lease liabilities (discounted)	$ 186,701	$ 189,238
LAND
Future minimum lease payments
2023	3,110
2024	12,442
2025	12,442
2026	12,442
2027	12,442
Thereafter	417,895
Total future minimum lease payments (undiscounted)	470,773
Difference between future undiscounted cash flows and discounted cash flows	(284,072)
Total operating lease liabilities (discounted)	$ 186,701

LEASES - Lessee Expenses (Detai

LEASES - Lessee Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Lease expense:
Contractual lease expense		$ 100	$ 100	$ 300
Variable lease expense	$ 200	100	1,000	500
Operating lease right-of-use asset amortization			2,600	2,500
Operating lease liabilities amortization			2,500	2,400
Maximum
Lease expense:
Contractual lease expense	100
LAND
Lease expense:
Contractual lease expense	3,293	3,226	9,877	9,760
Variable lease expense	42	28	103	81
LAND | Other operating expense
Lease expense:
Total operating lease expense	$ 3,335	$ 3,254	$ 9,980	$ 9,841

LEASES - Lessor (Details)

LEASES - Lessor (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Future minimum lease payments
Variable lease expense	$ 200	$ 100	$ 1,000	$ 500
Minimum
Lessor leases
Percentage of lease revenue			1%
Maximum
Lessor leases
Percentage of lease revenue			2%
Apartment Homes
Lessor leases
Option to extend			true
Apartment Homes | Maximum
Lessor leases
Lease terms	12 months		12 months
Retail and Commercial Spaces
Lessor leases
Option to extend			true
Future minimum lease payments
2023	$ 6,564		$ 6,564
2024	26,561		26,561
2025	23,717		23,717
2026	21,032		21,032
2027	17,155		17,155
Thereafter	70,079		70,079
Total future minimum payments	$ 165,108		$ 165,108
Retail and Commercial Spaces | Minimum
Lessor leases
Lease terms	5 years		5 years
Retail and Commercial Spaces | Maximum
Lessor leases
Lease terms	15 years		15 years

SECURED AND UNSECURED DEBT, N_3

SECURED AND UNSECURED DEBT, NET - Summary (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($) community	Dec. 31, 2022 USD ($)
Secured debt instruments
Total Debt, net	$ 5,752,822	$ 5,487,303
Long-term Debt	$ 5,763,454
Weighted average interest rate (as a percent)	3.37%
Weighted Average
Secured debt instruments
Years to maturity	5 years 10 months 24 days
Secured Debt
Secured debt instruments
Total Debt, net	$ 1,238,240	1,052,281
Long-term Debt	$ 1,241,110
Weighted average interest rate (as a percent)	3.45%
Number of Communities Encumbered | community	21
Secured Debt | Weighted Average
Secured debt instruments
Years to maturity	5 years
Unsecured Debt
Secured debt instruments
Total Debt, net	$ 4,514,582	4,435,022
Long-term Debt	$ 4,522,344
Weighted average interest rate (as a percent)	3.34%
Deferred finance costs, net	$ (21,638)	(24,040)
Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	6 years 1 month 6 days
Fixed Rate Debt | Secured Debt
Secured debt instruments
Total Debt, net	$ 1,211,287
Long-term Debt	1,214,110
Variable Rate Debt | Secured Debt
Secured debt instruments
Total Debt, net	26,953
Long-term Debt	27,000
Mortgages Notes Payable | Fixed Rate Debt | Secured Debt
Secured debt instruments
Total Debt, net	1,214,110	1,005,622
Deferred financing costs and other non-cash adjustments	2,823	(19,712)
Long-term Debt	$ 1,211,287	1,025,334
Weighted average interest rate (as a percent)	3.48%
Number of Communities Encumbered | community	20
Mortgages Notes Payable | Fixed Rate Debt | Secured Debt | Weighted Average
Secured debt instruments
Years to maturity	4 years 10 months 24 days
Tax-exempt notes payable | Variable Rate Debt | Secured Debt
Secured debt instruments
Total Debt, net	$ 26,953	26,947
Long-term Debt	$ 27,000	27,000
Weighted average interest rate (as a percent)	4.42%
Number of Communities Encumbered | community	1
Deferred finance costs, net	$ (47)	(53)
Tax-exempt notes payable | Variable Rate Debt | Secured Debt | Weighted Average
Secured debt instruments
Years to maturity	8 years 6 months
Unsecured Revolving Credit Facility Due January 2026 | Variable Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	2 years 3 months 18 days
Commercial Paper | Variable Rate Debt | Unsecured Debt
Secured debt instruments
Borrowings outstanding	$ 380,000	300,000
Weighted average interest rate (as a percent)	5.59%
Commercial Paper | Variable Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	1 month 6 days
Working capital credit facility | Variable Rate Debt | Unsecured Debt
Secured debt instruments
Borrowings outstanding	$ 26,700	28,015
Weighted average interest rate (as a percent)	6.19%
Working capital credit facility | Variable Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	3 months 18 days
Term Loan due January 2027 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Long-term Debt	$ 350,000	175,000
Weighted average interest rate (as a percent)	3.36%
Term Loan due January 2027 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	3 years 3 months 18 days
Term Loan due January 2027 | Variable Rate Debt | Unsecured Debt
Secured debt instruments
Long-term Debt		175,000
Term Loan due January 2027 | Variable Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	3 years 3 months 18 days
8.50% Debentures, Due September 2024 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Long-term Debt	$ 15,644	$ 15,644
Stated interest rate	8.50%	8.50%
Weighted average interest rate (as a percent)	8.50%
8.50% Debentures, Due September 2024 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	1 year
2.95% Medium-Term Note due September 2026 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Long-term Debt	$ 300,000	$ 300,000
Stated interest rate	2.95%	2.95%
Weighted average interest rate (as a percent)	2.89%
2.95% Medium-Term Note due September 2026 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	2 years 10 months 24 days
3.50 Medium-Term Note due July 2027 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 299,736	$ 299,683
Stated interest rate	3.50%	3.50%
Unamortized discount	$ 264	$ 317
Weighted average interest rate (as a percent)	4.03%
3.50 Medium-Term Note due July 2027 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	3 years 9 months 18 days
3.50% Medium-Term Notes Due January 2028 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 299,491	$ 299,402
Stated interest rate	3.50%	3.50%
Unamortized discount	$ 509	$ 598
Weighted average interest rate (as a percent)	3.50%
3.50% Medium-Term Notes Due January 2028 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	4 years 3 months 18 days
4.40% Medium-Term Notes due January 2029 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 299,997	$ 299,996
Stated interest rate	4.40%	4.40%
Unamortized discount	$ 3	$ 4
Weighted average interest rate (as a percent)	4.27%
4.40% Medium-Term Notes due January 2029 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	5 years 3 months 18 days
3.20% Medium-Term Notes due January 2030 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 608,637	$ 609,667
Stated interest rate	3.20%	3.20%
Unamortized net premium	$ 8,637	$ 9,667
Weighted average interest rate (as a percent)	3.32%
3.20% Medium-Term Notes due January 2030 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	6 years 3 months 18 days
3.00% Medium-Term Notes due August 2031
Secured debt instruments
Long-term Debt	$ 600,000
3.00% Medium-Term Notes due August 2031 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 609,408	$ 610,304
Stated interest rate	3%	3%
Unamortized net premium	$ 9,408	$ 10,304
Weighted average interest rate (as a percent)	3.01%
3.00% Medium-Term Notes due August 2031 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	7 years 10 months 24 days
2.10% Medium Term Note Due August 2032 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 399,689	399,662
Stated interest rate	2.10%
Unamortized discount	$ 311	338
Weighted average interest rate (as a percent)	2.10%
2.10% Medium Term Note Due August 2032 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	8 years 9 months 18 days
1.90% Medium-Term Notes due March 2033 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 348,860	$ 348,770
Stated interest rate	1.90%	1.90%
Unamortized discount	$ 1,140	$ 1,230
Weighted average interest rate (as a percent)	1.90%
1.90% Medium-Term Notes due March 2033 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	9 years 6 months
2.10% Medium-Term Note due June 2033 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 299,034	$ 298,959
Stated interest rate	2.10%	2.10%
Unamortized discount	$ 966	$ 1,041
Weighted average interest rate (as a percent)	2.10%
2.10% Medium-Term Note due June 2033 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	9 years 8 months 12 days
3.10% Medium-Term Notes due November 2034 | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 299,022	$ 298,955
Stated interest rate	3.10%	3.10%
Unamortized discount	$ 978	$ 1,045
Weighted average interest rate (as a percent)	3.13%
3.10% Medium-Term Notes due November 2034 | Fixed Rate Debt | Unsecured Debt | Weighted Average
Secured debt instruments
Years to maturity	11 years 1 month 6 days
Other [Member] | Fixed Rate Debt | Unsecured Debt
Secured debt instruments
Total Debt, net	$ 2	$ 5

SECURED AND UNSECURED DEBT, N_4

SECURED AND UNSECURED DEBT, NET - Credit Facilities (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) loan	Dec. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) instrument	Aug. 31, 2021 USD ($) instrument
Revolving Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	$ 1,300,000
Potential maximum available	$ 2,500,000
Number of Extensions of loan | loan	2
Extension period of option on loan	6 months
Revolving credit facility due 2023 | Letter of Credit
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding	$ 2,300	$ 2,600
Revolving credit facility due 2023 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	0.755%
Commitment fee	0.15%
Revolving credit facility due 2023 | Unsecured Debt | Minimum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	0.70%
Commitment fee	0.10%
Revolving credit facility due 2023 | Unsecured Debt | Maximum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	1.40%
Commitment fee	0.30%
Revolving credit facility due 2023 | Revolving Credit Facility
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	$ 1,300,000	1,300,000
Weighted average daily borrowings during the period ended	2,747	3,776
Maximum daily borrowings during the period ended	$ 250,000	$ 205,000
Weighted average interest rate during the period ended	5.60%	3.90%
Term Loan due September 2023 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	0.83%
basis point subtracted from variable rate for Company receiving green building certifications	0.02%
Term Loan due September 2023 | Unsecured Debt | Minimum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	0.75%
Term Loan due September 2023 | Unsecured Debt | Maximum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	1.60%
Term Loan Facility Due January 2027
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Total revolving credit facility	$ 350,000
Term Loan Facility Due July 2025 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Notional			$ 350,000	$ 350,000
Number of interest rate swaps | instrument			5	5
March 2023 until January 2024 | Term Loan Facility Due July 2025 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding			$ 350,000	$ 350,000
All-in weighted average interest rate			3.36%	3.36%
January 2024 until July 2024 | Term Loan Facility Due July 2025 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding			$ 262,500	$ 262,500
All-in weighted average interest rate			2.68%	2.68%
July 2024 until July 2025 | Term Loan Facility Due July 2025 | Unsecured Debt
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Borrowings outstanding			$ 175,000	$ 175,000
All-in weighted average interest rate			1.43%	1.43%

SECURED AND UNSECURED DEBT, N_5

SECURED AND UNSECURED DEBT, NET - Working Capital Credit Facility (Details) - Working capital credit facility - Variable Rate Debt - Unsecured Debt - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
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	26,700	28,015
Weighted average daily borrowings during the period ended	16,920	15,080
Maximum daily borrowings during the period ended	$ 57,107	$ 55,812
Weighted average interest rate during the period ended	5.80%	3%
Interest rate at end of the period	6.20%	5.20%
Basis points added to to variable rate	0.775%
Minimum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	0.70%
Maximum
Summary of short-term bank borrowings under unsecured commercial bank credit facility
Basis points added to to variable rate	1.40%

SECURED AND UNSECURED DEBT, N_6

SECURED AND UNSECURED DEBT, NET - Short Term Debt (Details) - Variable Rate Debt - Unsecured Debt - Commercial Paper - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Secured and Unsecured Debt
Total unsecured commercial paper program	$ 700,000	$ 700,000
Borrowings outstanding at end of period	380,000	300,000
Weighted average daily borrowings during the period ended	378,941	405,671
Maximum daily borrowings during the period ended	$ 505,000	$ 700,000
Weighted average interest rate during the period ended	5.30%	2.30%
Interest rate at end of the period	5.60%	4.70%

SECURED AND UNSECURED DEBT, N_7

SECURED AND UNSECURED DEBT, NET - Unsecured Maturities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Aggregate maturities of unsecured debt
2023	$ 380,359		$ 380,359
2024	139,922		139,922
2025	178,568		178,568
2026	356,665		356,665
2027	656,931		656,931
2028	466,518		466,518
2029	615,802		615,802
2030	830,759		830,759
2031	760,930		760,930
2032	427,000		427,000
Thereafter	950,000		950,000
Subtotal	5,763,454		5,763,454
Non-cash	(10,632)		(10,632)
Total	5,752,822		5,752,822		$ 5,487,303
Interest expense
Aggregate maturities of unsecured debt
Amortization of financing costs	1,000	$ 1,000	2,900	$ 2,900
Secured Debt
Aggregate maturities of unsecured debt
2023	359		359
2024	97,578		97,578
2025	178,568		178,568
2026	56,665		56,665
2027	6,931		6,931
2028	166,518		166,518
2029	315,802		315,802
2030	230,759		230,759
2031	160,930		160,930
2032	27,000		27,000
Subtotal	1,241,110		1,241,110
Non-cash	(2,870)		(2,870)
Total	1,238,240		1,238,240		1,052,281
Secured Debt | Fixed Rate Debt
Aggregate maturities of unsecured debt
2023	359		359
2024	97,578		97,578
2025	178,568		178,568
2026	56,665		56,665
2027	6,931		6,931
2028	166,518		166,518
2029	315,802		315,802
2030	230,759		230,759
2031	160,930		160,930
Subtotal	1,214,110		1,214,110
Non-cash	(2,823)		(2,823)
Total	1,211,287		1,211,287
Secured Debt | Variable Rate Debt
Aggregate maturities of unsecured debt
2032	27,000		27,000
Subtotal	27,000		27,000
Non-cash	(47)		(47)
Total	26,953		26,953
Unsecured Debt
Aggregate maturities of unsecured debt
2023	380,000		380,000
2024	42,344		42,344
2025	0		0
2026	300,000		300,000
2027	650,000		650,000
2028	300,000		300,000
2029	300,000		300,000
2030	600,000		600,000
2031	600,000		600,000
2032	400,000		400,000
Thereafter	950,000		950,000
Subtotal	4,522,344		4,522,344
Non-cash	(7,762)		(7,762)
Total	$ 4,514,582		$ 4,514,582		$ 4,435,022

SECURED AND UNSECURED DEBT, N_8

SECURED AND UNSECURED DEBT, NET - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2023 USD ($) community loan	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Secured Debt
Percentage of secured debt which encumbers real estate owned based upon book value		13%		13%
Percentage of secured debt of real estate owned which is unencumbered		87%		87%
Long-term Debt		$ 5,752,822		$ 5,752,822		$ 5,487,303
Outstanding balances		5,763,454		5,763,454
Texas Operating Communities
Secured Debt
Number of communities acquired | community	6
Number of mortgage loans acquired | loan	6
Mortgages Notes Payable | Texas Operating Communities
Secured Debt
Long-term Debt	$ 209,400
Long term debt fair value	$ 191,700
Number of communities acquired | community	6
Number of mortgage loans acquired | loan	6
Outstanding balances	$ 209,400
Mortgages Notes Payable | Texas Operating Communities | Minimum
Secured Debt
Notes payable maximum interest rates range	3.24%
Outstanding balances	$ 28,000
Mortgages Notes Payable | Texas Operating Communities | Maximum
Secured Debt
Notes payable maximum interest rates range	4.12%
Outstanding balances	$ 40,000
3.00% Medium-Term Notes due August 2031
Secured Debt
Outstanding balances		600,000		600,000
Interest rate risk		$ 250,000		$ 250,000
All-in weighted average interest rate		3.01%		3.01%
Unsecured Debt
Secured Debt
Long-term Debt		$ 4,514,582		$ 4,514,582		4,435,022
Outstanding balances		4,522,344		4,522,344
Secured Debt
Secured Debt
Long-term Debt		1,238,240		1,238,240		1,052,281
Outstanding balances		$ 1,241,110		$ 1,241,110
Fixed Rate Debt | Mortgages Notes Payable | Minimum
Secured Debt
Notes payable maximum interest rates range		2.62%		2.62%
Fixed Rate Debt | Mortgages Notes Payable | Maximum
Secured Debt
Notes payable maximum interest rates range		4.39%		4.39%
Fixed Rate Debt | Unsecured Debt | 2.95% Medium-Term Note due September 2026
Secured Debt
Outstanding balances		$ 300,000		$ 300,000		$ 300,000
Stated interest rate		2.95%		2.95%		2.95%
Portion of medium term note subject to interest rate swaps		$ 100,000		$ 100,000
All-in weighted average interest rate		2.89%		2.89%
Fixed Rate Debt | Unsecured Debt | 3.50 Medium-Term Note due July 2027
Secured Debt
Long-term Debt		$ 299,736		$ 299,736		$ 299,683
Stated interest rate		3.50%		3.50%		3.50%
Portion of medium term note subject to interest rate swaps		$ 200,000		$ 200,000
All-in weighted average interest rate		4.03%		4.03%
Fixed Rate Debt | Unsecured Debt | 4.40% Medium-Term Notes due January 2029
Secured Debt
Principal outstanding		$ 300,000		$ 300,000
Long-term Debt		$ 299,997		$ 299,997		$ 299,996
Stated interest rate		4.40%		4.40%		4.40%
Portion of medium term note subject to interest rate swaps		$ 150,000		$ 150,000
All-in weighted average interest rate		4.27%		4.27%
Fixed Rate Debt | Unsecured Debt | 3.20% Medium-Term Notes due January 2030
Secured Debt
Long-term Debt		$ 608,637		$ 608,637		$ 609,667
Stated interest rate		3.20%		3.20%		3.20%
All-in weighted average interest rate		3.32%		3.32%
Unamortized net premium		$ 8,637		$ 8,637		$ 9,667
Fixed Rate Debt | Unsecured Debt | 3.00% Medium-Term Notes due August 2031
Secured Debt
Long-term Debt		$ 609,408		$ 609,408		$ 610,304
Stated interest rate		3%		3%		3%
Unamortized net premium		$ 9,408		$ 9,408		$ 10,304
Fixed Rate Debt | Unsecured Debt | 2.10% Medium Term Note Due August 2032
Secured Debt
Long-term Debt		$ 399,689		$ 399,689		399,662
Stated interest rate		2.10%		2.10%
Fixed Rate Debt | Unsecured Debt | 2.10% Medium-Term Note due June 2033
Secured Debt
Long-term Debt		$ 299,034		$ 299,034		$ 298,959
Stated interest rate		2.10%		2.10%		2.10%
Fixed Rate Debt | Unsecured Debt | 3.10% senior unsecured notes due 2034
Secured Debt
All-in weighted average interest rate		3.13%		3.13%
Fixed Rate Debt | Unsecured Debt | 1.90% Medium-Term Notes due March 2033
Secured Debt
Long-term Debt		$ 348,860		$ 348,860		$ 348,770
Stated interest rate		1.90%		1.90%		1.90%
Fixed Rate Debt | Secured Debt
Secured Debt
Long-term Debt		$ 1,211,287		$ 1,211,287
Outstanding balances		1,214,110		1,214,110
Fixed Rate Debt | Secured Debt | Mortgages Notes Payable
Secured Debt
Long-term Debt		1,214,110		1,214,110		$ 1,005,622
Outstanding balances		1,211,287		1,211,287		1,025,334
Fixed Rate Debt | Debt Assumed As Part of Acquisition | Mortgages Notes Payable
Secured Debt
Amortization of debt discount (Premium)		800	$ 1,100	3,000	$ 3,300
Unamortized net premium		1,900		1,900		$ 22,500
Variable Rate Debt | Secured Debt
Secured Debt
Long-term Debt		26,953		26,953
Outstanding balances		27,000		27,000
Variable Rate Debt | Tax-exempt notes payable | Mortgages Notes Payable
Secured Debt
Principal outstanding		$ 27,000		$ 27,000
Variable Rate Debt | Tax-exempt secured notes payable | Mortgages Notes Payable
Secured Debt
Notes payable maximum interest rates range		4.42%		4.42%

INCOME_(LOSS) PER SHARE (Detail

INCOME/(LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jul. 31, 2021
Antidilutive securities
Net income/(loss)	$ 35,419	$ 25,145	$ 438,527	$ 45,112
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(2,554)	(1,533)	(27,137)	(2,684)
Net (income)/loss attributable to noncontrolling interests	(7)	(7)	(23)	(34)
Net income/(loss) attributable to UDR, Inc.	32,858	23,605	411,367	42,394
Distributions to preferred stockholders - Series E (Convertible)	(1,221)	(1,106)	(3,626)	(3,307)
Net income/(loss) attributable to common stockholders	$ 31,637	$ 22,499	$ 407,741	$ 39,087
Denominator for income/(loss) per share:
Weighted average common shares outstanding	329,130,000	324,983,000	329,207,000	320,654,000
Non-vested restricted stock awards	(370,000)	(282,000)	(372,000)	(276,000)
Denominator for basic income/(loss) per share	328,760,000	324,701,000	328,835,000	320,378,000
Incremental shares issuable from assumed conversion of unvested LTIP Units, performance units, unvested restricted stock and shares issuable upon settlement of forward sales agreements	441,000	985,000	448,000	1,251,000
Denominator for diluted income/(loss) per share	329,201,000	325,686,000	329,283,000	321,629,000
Income/(loss) per weighted average common share - basic	$ 0.10	$ 0.07	$ 1.24	$ 0.12
Income/(loss) per weighted average common share - diluted	$ 0.10	$ 0.07	$ 1.24	$ 0.12
Number of shares authorized	450,000,000		450,000,000		450,000,000
Aggregate net proceeds			$ (473)	$ 449,945
Number of shares agreed to repurchase (in shares)	600,000		600,000
Average price of shares to be repurchased (dollar per share)	$ 40.13		$ 40.13
Approximate amount committed for the repurchase of common shares	$ 25,000		$ 25,009	15,150
Issuance of common shares through public offering, net		$ 99,677	$ (473)	$ 449,945
OP/DownREIT Units
Denominator for income/(loss) per share:
Antidilutive securities	22,511,000	21,474,000	21,699,000	21,514,000
Convertible Preferred Stock
Denominator for income/(loss) per share:
Antidilutive securities	2,908,000	2,918,000	2,908,000	2,918,000
Unvested LTIP Units and unvested restricted stock
Denominator for income/(loss) per share:
Antidilutive securities	441,000	985,000	448,000	1,251,000
ATM
Denominator for income/(loss) per share:
Number of shares authorized						20,000,000
Shares of common stock available for future issuance	14,000,000		14,000,000

NONCONTROLLING INTERESTS (Detai

NONCONTROLLING INTERESTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Noncontrolling interests
Minimum holding period prior to redemption (in years)			1 year
Redeemable noncontrolling interests in the Operating Partnership
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, at beginning of year			$ 839,850
Mark-to-market adjustment to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	$ (159,298)	$ (90,252)	(65,799)	$ (376,515)
OP Units issued for real estate, net			141,359
Conversion of OP Units/DownREIT Units to Common Stock			26,537
Net income/(loss) attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	2,554	1,533	27,137	2,684
Distributions to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership			(29,203)
Redeemable Long-Term and Short-Term Incentive Plan Units			20,474
Allocation of other comprehensive income/(loss)			(12)
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership, at end of year	907,269		907,269
Net (income)/loss attributable to noncontrolling interests	(7)	(7)	(23)	(34)
Maximum
Redeemable noncontrolling interests in the Operating Partnership
Net (income)/loss attributable to noncontrolling interests	$ (100)	$ (100)	$ (100)	$ (100)

FAIR VALUE OF DERIVATIVES AND_3

FAIR VALUE OF DERIVATIVES AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Fair Value
Notes receivable, net	$ 209,297	$ 54,707
Debt instruments - fair value
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	907,269	839,850
Transfers between levels of fair value hierarchy	0
Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	209,297	54,707
Total assets	241,227	79,684
Debt instruments - fair value
Total liabilities	5,779,208	5,514,231
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	907,269	839,850
Carrying (Reported) Amount, Fair Value Disclosure | 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	14,150	15,270
Carrying (Reported) Amount, Fair Value Disclosure | Equity Securities | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	17,780	9,707
Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	211,278	55,514
Total assets	243,208	80,491
Debt instruments - fair value
Total liabilities	4,931,298	4,712,688
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	907,269	839,850
Estimate of Fair Value, Fair Value Disclosure | 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	14,150	15,270
Estimate of Fair Value, Fair Value Disclosure | Equity Securities | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	17,780	9,707
Estimate of Fair Value, Fair Value Disclosure | Level 1 | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	17,780	9,707
Estimate of Fair Value, Fair Value Disclosure | Level 1 | Equity Securities | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Equity securities	17,780	9,707
Estimate of Fair Value, Fair Value Disclosure | Level 2 | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Total assets	14,150	15,270
Debt instruments - fair value
Redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	907,269	839,850
Estimate of Fair Value, Fair Value Disclosure | 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	14,150	15,270
Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Estimated fair values of the financial instruments either recorded or disclosed on a recurring basis
Notes receivable	211,278	55,514
Total assets	211,278	55,514
Debt instruments - fair value
Total liabilities	4,931,298	4,712,688
Unsecured Debt | Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	4,129,520	4,131,047
Unsecured Debt | Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	3,418,985	3,448,632
Unsecured Debt | Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	3,418,985	3,448,632
Unsecured Debt | Working capital credit facility | Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	26,700	28,015
Unsecured Debt | Working capital credit facility | Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	26,700	28,015
Unsecured Debt | Working capital credit facility | Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	26,700	28,015
Unsecured Debt | Commercial Paper | Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	380,000	300,000
Unsecured Debt | Commercial Paper | Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	380,000	300,000
Unsecured Debt | Commercial Paper | Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	380,000	300,000
Fixed Rate Debt | Secured Debt | Mortgages Notes Payable | Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,215,988	1,028,169
Fixed Rate Debt | Secured Debt | Mortgages Notes Payable | Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,078,613	909,041
Fixed Rate Debt | Secured Debt | Mortgages Notes Payable | Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	1,078,613	909,041
Variable Rate Debt | Secured Debt | Tax-exempt secured notes payable | Carrying (Reported) Amount, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt | Secured Debt | Tax-exempt secured notes payable | Estimate of Fair Value, Fair Value Disclosure | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	27,000	27,000
Variable Rate Debt | Secured Debt | Tax-exempt secured notes payable | Estimate of Fair Value, Fair Value Disclosure | Level 3 | Fair Value, Measurements, Recurring
Debt instruments - fair value
Fair value	$ 27,000	$ 27,000

DERIVATIVES AND HEDGING ACTIV_3

DERIVATIVES AND HEDGING ACTIVITY - Interest Rate Derivatives (Details) $ in Thousands	Sep. 30, 2023 USD ($) instrument
Derivatives
Estimated additional accumulated other comprehensive Income/(Loss) transferred to interest expense	$ 7,600
Designated as Hedging Instrument | Interest rate swap and caps
Derivatives
Number of Interest Rate Derivatives Held | instrument	6
Notional	$ 369,880
Not Designated as Hedging Instrument
Derivatives
Notional	$ 0

DERIVATIVES AND HEDGING ACTIV_4

DERIVATIVES AND HEDGING ACTIVITY - Undesignated Interest Rate Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Interest rate contracts | Other assets | Designated as Hedging Instrument
Fair value of Company's derivative financial instruments and their classification on Consolidated Balance Sheets
Derivative Asset Designated as Hedging Instrument, Fair Value	$ 14,150	$ 15,270

DERIVATIVES AND HEDGING ACTIV_5

DERIVATIVES AND HEDGING ACTIVITY - Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Effect of derivative instruments on the Consolidated Statements of Operations
Unrealized holding gain/(loss)	$ 1,314	$ 5,048	$ 5,336	$ 13,988
Gain/(Loss) reclassified from Accumulated OCI in Interest Expense	2,110	313	5,332	28
Interest rate contracts | Interest expense | Cash Flow Hedging
Effect of derivative instruments on the Consolidated Statements of Operations
Unrealized holding gain/(loss)	1,314	5,048	5,336	13,988
Gain/(Loss) reclassified from Accumulated OCI in Interest Expense	$ 2,110	$ 313	$ 5,332	$ 28

DERIVATIVES AND HEDGING ACTIV_6

DERIVATIVES AND HEDGING ACTIVITY - Effectiveness (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivatives and hedging activity
Total amount of Interest expense presented on the Consolidated Statements of Operations	$ 44,664	$ 39,905	$ 133,519	$ 112,653

DERIVATIVES AND HEDGING ACTIV_7

DERIVATIVES AND HEDGING ACTIVITY - Offsetting Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Offsetting derivative assets
Net Amounts of Assets Presented in the Consolidated Balance Sheets (a)	$ 14,150	$ 15,270
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets.	Other Assets.
Net Amount	$ 14,150	$ 15,270

STOCK BASED COMPENSATION (Detai

STOCK BASED COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
General and administrative expense
Stock based compensation
Stock based compensation expense	$ 7.1	$ 6.7	$ 22.8	$ 20.5

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Sep. 30, 2023 USD ($) community
Real estate properties
Number of communities | community	168
Costs Incurred to Date	$ 225,327
UDR's Remaining Commitment	163,173
Real estate technology investments
Real estate properties
Costs Incurred to Date	50,931
UDR's Remaining Commitment	$ 45,069
Wholly owned - under development
Real estate properties
Number of communities | community	2
Costs Incurred to Date	$ 139,143
UDR's Remaining Commitment	$ 48,357
Wholly owned - redevelopment
Real estate properties
Number of communities | community	8
Costs Incurred to Date	$ 35,253
UDR's Remaining Commitment	$ 69,747

REPORTABLE SEGMENTS (Details)

REPORTABLE SEGMENTS (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) home	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) home segment	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segments
Same store communities | home	52,291		51,858
Reportable Segments
Management fee (as a percent)			3.25%
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	$ 408,359	$ 390,023	$ 1,209,764	$ 1,113,952
Reconciling items:
Joint venture management and other fees	$ 1,772	$ 1,274	$ 4,464	$ 3,778
Type of revenue	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember	udr:ManagementAndOtherFeesMember
Property management	$ (13,271)	$ (12,675)	$ (39,317)	$ (36,203)
Other operating expenses	(4,611)	(3,746)	(11,902)	(13,485)
Real estate depreciation and amortization	(167,551)	(166,781)	(505,776)	(497,987)
General and administrative	(15,159)	(15,840)	(49,091)	(47,333)
Casualty-related (charges)/recoveries, net	1,928	(901)	(3,362)	(1,210)
Other depreciation and amortization	(3,692)	(3,430)	(11,022)	(9,521)
Gain/(loss) on sale of real estate owned	0	0	325,885	0
Income/(loss) from unconsolidated entities	5,508	10,003	24,912	4,186
Interest expense	(44,664)	(39,905)	(133,519)	(112,653)
Interest income and other income/(expense), net	(3,069)	(7,495)	8,388	(6,934)
Tax (provision)/benefit, net	(428)	(377)	(2,013)	(1,032)
Net (income)/loss attributable to redeemable noncontrolling interests in the Operating Partnership and DownREIT Partnership	(2,554)	(1,533)	(27,137)	(2,684)
Net (income)/loss attributable to noncontrolling interests	(7)	(7)	(23)	(34)
Net income/(loss) attributable to UDR, Inc.	32,858	23,605	411,367	42,394
Reportable apartment home segment assets:
Total segment assets	15,918,624		15,918,624		$ 15,570,072
Accumulated depreciation	(6,117,312)		(6,117,312)		(5,762,501)
Total real estate owned, net of accumulated depreciation	9,801,312		9,801,312		9,807,571
Reconciling items:
Cash and cash equivalents	1,624	1,532	1,624	1,532	1,193	$ 967
Restricted cash	30,831	28,363	30,831	28,363	29,001	$ 27,451
Notes receivable, net	209,297		209,297		54,707
Investment in and advances to unconsolidated joint ventures, net	963,927		963,927		754,446
Operating lease right-of-use assets	191,499		191,499		194,081
Other assets	221,572		221,572		197,471
Total consolidated assets	11,420,062		11,420,062		11,038,470
Total Communities
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue	394,894	376,847	1,172,542	1,078,361
Other revenue	13,465	13,176	37,222	35,591
Rental income	408,359	390,023	1,209,764	1,113,952
Reportable apartment home segment NOI	278,656	265,018	830,880	763,506
Same Communities | Same Store Communities Western Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue	119,203	114,322	351,822	334,229
Other revenue	3,106	3,220	8,837	9,059
Rental income	122,309	117,542	360,659	343,288
Reportable apartment home segment NOI	90,574	87,095	269,108	256,265
Reportable apartment home segment assets:
Total segment assets	4,415,840		4,415,840		4,363,452
Same Communities | 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	78,462	74,999	231,564	219,043
Other revenue	3,436	3,149	8,884	8,534
Rental income	81,898	78,148	240,448	227,577
Reportable apartment home segment NOI	55,921	53,317	165,552	156,286
Reportable apartment home segment assets:
Total segment assets	3,295,218		3,295,218		3,245,297
Same Communities | 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	79,958	74,857	225,868	208,950
Other revenue	2,095	2,295	5,282	5,232
Rental income	82,053	77,152	231,150	214,182
Reportable apartment home segment NOI	53,392	49,990	152,212	139,301
Reportable apartment home segment assets:
Total segment assets	3,876,325		3,876,325		3,834,761
Same Communities | Same Store Communities Southeastern Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue	57,035	53,811	169,613	154,306
Other revenue	2,571	2,245	7,030	6,576
Rental income	59,606	56,056	176,643	160,882
Reportable apartment home segment NOI	40,667	37,854	121,018	108,904
Reportable apartment home segment assets:
Total segment assets	1,572,392		1,572,392		1,521,489
Same Communities | Same Store Communities Southwestern Region
Summary of rental income and NOI for UDRs reportable segments and reconciliation of NOI to loss from continuing operations
Lease revenue	37,872	36,801	113,139	106,220
Other revenue	1,813	1,647	4,795	4,337
Rental income	39,685	38,448	117,934	110,557
Reportable apartment home segment NOI	25,587	23,611	75,449	69,356
Reportable apartment home segment assets:
Total segment assets	1,319,617		1,319,617		1,287,332
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	22,364	22,057	80,536	55,613
Other revenue	444	620	2,394	1,853
Rental income	22,808	22,677	82,930	57,466
Reportable apartment home segment NOI	12,515	$ 13,151	47,541	$ 33,394
Reportable apartment home segment assets:
Total segment assets	$ 1,439,232		$ 1,439,232		$ 1,317,741

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 32,858	$ 23,605	$ 411,367	$ 42,394

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false