CubeSmart 10-Q 30 Apr 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 28, 2021
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Entity File Number	001-32324
Entity Registrant Name	CUBESMART
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	20-1024732
Entity Address, Address Line One	5 Old Lancaster Rd. Malvern
Entity Address, City or Town	Malvern
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19355
City Area Code	610
Local Phone Number	535-5000
Title of 12(b) Security	Common Shares, $0.01 par value per share, of CubeSmart
Trading Symbol	CUBE
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		201,516,797
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001298675
Amendment Flag	false
Cubesmart, L P and Subsidiaries
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Entity File Number	000-54462
Entity Registrant Name	CUBESMART, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	34-1837021
Entity Address, Address Line One	5 Old Lancaster Rd.
Entity Address, City or Town	Malvern
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19355
City Area Code	610
Local Phone Number	535-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001300485
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Storage properties	$ 5,492,183	$ 5,489,754
Less: Accumulated depreciation	(997,712)	(983,940)
Storage properties, net (including VIE assets of $136,141 and $119,345, respectively)	4,494,471	4,505,814
Cash and cash equivalents	3,650	3,592
Restricted cash	2,342	2,637
Loan procurement costs, net of amortization	3,029	3,275
Investment in real estate ventures, at equity	93,797	92,071
Other assets, net	157,189	170,753
Total assets	4,754,478	4,778,142
LIABILITIES AND EQUITY
Unsecured senior notes, net	2,030,999	2,030,372
Revolving credit facility	52,800	117,800
Mortgage loans and notes payable, net	171,189	216,504
Accounts payable, accrued expenses and other liabilities	166,025	159,140
Lease liabilities - finance leases	65,710	65,599
Distributions payable	70,854	68,301
Deferred revenue	30,974	29,087
Security deposits	1,079	1,077
Total liabilities	2,589,630	2,687,880
Noncontrolling interests in the Operating Partnership	278,649	249,414
Commitments and contingencies
Equity
Common shares $.01 par value, 400,000,000 shares authorized, 200,421,556 and 197,405,989 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	2,004	1,974
Additional paid-in capital	2,909,730	2,805,673
Accumulated other comprehensive loss	(613)	(632)
Accumulated deficit	(1,033,519)	(974,799)
Total CubeSmart shareholders' equity	1,877,602	1,832,216
Noncontrolling interests in subsidiaries	8,597	8,632
Total equity	1,886,199	1,840,848
Total liabilities and equity	$ 4,754,478	$ 4,778,142

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Storage properties	$ 4,494,471	$ 4,505,814
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, shares authorized	400,000,000	400,000,000
Common shares, shares issued	200,421,556	197,405,989
Common shares, shares outstanding	200,421,556	197,405,989
VIE
Storage properties	$ 136,141	$ 119,345

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
REVENUES
Rental income	$ 162,476	$ 140,985
Total revenues	188,841	164,081
OPERATING EXPENSES
Property operating expenses	61,228	55,740
Depreciation and amortization	53,810	40,838
General and administrative	10,916	10,365
Total operating expenses	125,954	106,943
Interest:
Interest expense on loans	(19,234)	(18,681)
Loan procurement amortization expense	(1,035)	(754)
Equity in earnings (losses) of real estate ventures	20	(5)
Other	677	619
Total other expense	(19,572)	(18,821)
NET INCOME	43,315	38,317
NET (INCOME) LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS
Noncontrolling interests in the Operating Partnership	(1,549)	(383)
Noncontrolling interest in subsidiaries	(34)	(38)
NET INCOME ATTRIBUTABLE TO THE COMPANY'S COMMON SHAREHOLDERS	$ 41,732	$ 37,896
Basic earnings per share attributable to common shareholders (in dollars per share)	$ 0.21	$ 0.20
Diluted earnings per share attributable to common shareholders (in dollars per share)	$ 0.21	$ 0.20
Weighted average basic shares outstanding (in shares)	199,160	193,582
Weighted average diluted shares outstanding (in shares)	200,233	194,264
Other Property Related Income
REVENUES
Property related income	$ 19,304	$ 16,902
Property Management Fee Income
REVENUES
Property related income	$ 7,061	$ 6,194

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
NET INCOME	$ 43,315	$ 38,317
Other comprehensive income (loss):
Reclassification of realized losses on interest rate swaps	20	20
OTHER COMPREHENSIVE INCOME	20	20
COMPREHENSIVE INCOME	43,335	38,337
Comprehensive income attributable to noncontrolling interests in the Operating Partnership	(1,550)	(383)
Comprehensive income attributable to noncontrolling interest in subsidiaries	(34)	(38)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE COMPANY	$ 41,751	$ 37,916

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total Shareholders' Equity	Common Shares	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit	Noncontrolling Interest in Subsidiaries	Noncontrolling Interests in Operating Partnership	Total
Balance at Dec. 31, 2019	$ 1,799,346	$ 1,936	$ 2,674,745	$ (729)	$ (876,606)	$ 7,990		$ 1,807,336
Balance (in shares) at Dec. 31, 2019		193,557
Balance of Noncontrolling Interests in the Operating Partnership at Dec. 31, 2019							$ 62,088
Increase (Decrease) in Stockholders' Equity
Distributions paid to noncontrolling interests in subsidiaries						(59)		(59)
Issuance of common shares, net	(118)		(118)					(118)
Issuance of restricted shares (in shares)		30
Amortization of restricted shares	710		710					710
Share compensation expense	530		530					530
Adjustment for noncontrolling interest in the Operating Partnership	7,976				7,976		(7,976)	7,976
Net income (loss)	37,896				37,896	38		37,934
Net income (loss)							383
Other comprehensive income (loss), net	20			20				20
Common share distributions	(64,039)				(64,039)		(650)	(64,039)
Balance at Mar. 31, 2020	1,782,321	$ 1,936	2,675,867	(709)	(894,773)	7,969		1,790,290
Balance (in shares) at Mar. 31, 2020		193,587
Balance of Noncontrolling Interests in the Operating Partnership at Mar. 31, 2020							53,845
Balance at Dec. 31, 2019	1,799,346	$ 1,936	2,674,745	(729)	(876,606)	7,990		1,807,336
Balance (in shares) at Dec. 31, 2019		193,557
Balance of Noncontrolling Interests in the Operating Partnership at Dec. 31, 2019							62,088
Increase (Decrease) in Stockholders' Equity
Adjustment for noncontrolling interest in the Operating Partnership								(4,200)
Balance at Dec. 31, 2020	1,832,216	$ 1,974	2,805,673	(632)	(974,799)	8,632		1,840,848
Balance (in shares) at Dec. 31, 2020		197,406
Balance of Noncontrolling Interests in the Operating Partnership at Dec. 31, 2020							249,414	249,414
Increase (Decrease) in Stockholders' Equity
Distributions paid to noncontrolling interests in subsidiaries						(69)		(69)
Issuance of common shares, net	99,688	$ 28	99,660					99,688
Issuance of common shares, net (in shares)		2,837
Issuance of restricted shares (in shares)		32
Conversion from units to shares	1,913	$ 1	1,912				(1,913)	1,913
Conversion from units to shares (in shares)		55
Exercise of stock options	1,172	$ 1	1,171					1,172
Exercise of stock options (in shares)		92
Amortization of restricted shares	705		705					705
Share compensation expense	609		609					609
Adjustment for noncontrolling interest in the Operating Partnership	(32,102)				(32,102)		32,102	(32,102)
Net income (loss)	41,732				41,732	34		41,766
Net income (loss)							1,549
Other comprehensive income (loss), net	19			19			1	19
Common share distributions	(68,350)				(68,350)		(2,504)	(68,350)
Balance at Mar. 31, 2021	$ 1,877,602	$ 2,004	$ 2,909,730	$ (613)	$ (1,033,519)	$ 8,597		1,886,199
Balance (in shares) at Mar. 31, 2021		200,422
Balance of Noncontrolling Interests in the Operating Partnership at Mar. 31, 2021							$ 278,649	$ 278,649

CONSOLIDATED STATEMENTS OF EQ_2

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONSOLIDATED STATEMENTS OF EQUITY
Common share distributions (in dollars per share)	$ 0.34	$ 0.33

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Activities
Net income	$ 43,315	$ 38,317
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	54,845	41,592
Non-cash portion of interest expense related to finance leases	111
Equity in (earnings) losses of real estate ventures	(20)	5
Equity compensation expense	2,042	1,871
Accretion of fair market value adjustment of debt	(607)	(176)
Changes in other operating accounts:
Other assets	(1,718)	2,743
Accounts payable and accrued expenses	(1,675)	(3,743)
Other liabilities	1,889	340
Net cash provided by operating activities	98,182	80,949
Investing Activities
Acquisitions of storage properties		(9,090)
Additions and improvements to storage properties	(7,894)	(11,923)
Development costs	(10,932)	(9,709)
Investment in real estate ventures	(6,664)	(5,877)
Cash distributed from real estate ventures	4,958	1,815
Net cash used in investing activities	(20,532)	(34,784)
Proceeds from:
Revolving credit facility	268,111	5,127
Principal payments on:
Revolving credit facility	(333,111)	(5,127)
Mortgage loans and notes payable	(44,649)	(633)
Proceeds from issuance of common shares, net	99,688	(118)
Cash paid upon vesting of restricted shares	(728)	(631)
Exercise of stock options	1,172
Distributions paid to noncontrolling interests in subsidiaries	(69)	(59)
Distributions paid to common shareholders	(67,368)	(64,036)
Distributions paid to noncontrolling interests in Operating Partnership	(933)	(650)
Net cash provided by financing activities	(77,887)	(66,127)
Change in cash, cash equivalents and restricted cash	(237)	(19,962)
Cash, cash equivalents and restricted cash at beginning of period	6,229	58,441
Cash, cash equivalents and restricted cash at end of period	5,992	38,479
Supplemental Cash Flow and Noncash Information
Cash paid for interest, net of interest capitalized	23,534	23,652
Supplemental disclosure of noncash activities:
Accretion of put liability	2,823	896
Derivative valuation adjustment	$ 20	$ 20

ORGANIZATION AND NATURE OF OPER

ORGANIZATION AND NATURE OF OPERATIONS	3 Months Ended
	Mar. 31, 2021
ORGANIZATION AND NATURE OF OPERATIONS
ORGANIZATION AND NATURE OF OPERATIONS	1. ORGANIZATION AND NATURE OF OPERATIONS ​ CubeSmart (the “Parent Company”) operates as a self-managed and self-administered real estate investment trust (“REIT”) with its operations conducted solely through CubeSmart, L.P. and its subsidiaries. CubeSmart, L.P., a Delaware limited partnership (the “Operating Partnership”), operates through an umbrella partnership structure, with the Parent Company, a Maryland REIT, as its sole general partner. In the notes to the consolidated financial statements, we use the terms “the Company”, “we” or “our” to refer to the Parent Company and the Operating Partnership together, unless the context indicates otherwise. As of March 31, 2021, the Company owned self-storage properties located in 24 states throughout the United States and the District of Columbia that are presented under one reportable segment: the Company owns, operates, develops, manages and acquires self-storage properties. ​ As of March 31, 2021, the Parent Company owned approximately 96.5% of the partnership interests (“OP Units”) of the Operating Partnership. The remaining OP Units, consisting exclusively of limited partner interests, are held by persons who contributed their interests in properties to the Operating Partnership in exchange for OP Units. Under the partnership agreement, these persons have the right to tender their OP Units for redemption to the Operating Partnership at any time following a specified restricted period for cash equal to the fair value of an equivalent number of common shares of the Parent Company. In lieu of delivering cash, however, the Parent Company, as the Operating Partnership’s general partner, may, at its option, choose to acquire any OP Units so tendered by issuing common shares in exchange for the tendered OP Units. If the Parent Company so chooses, its common shares will be exchanged for OP Units on a one-for-one basis. This one-for-one exchange ratio is subject to adjustment to prevent dilution. With each such exchange or redemption, the Parent Company’s percentage ownership in the Operating Partnership will increase. In addition, whenever the Parent Company issues common or other classes of its shares, it contributes the net proceeds it receives from the issuance to the Operating Partnership and the Operating Partnership issues to the Parent Company an equal number of OP Units or other partnership interests having preferences and rights that mirror the preferences and rights of the shares issued. This structure is commonly referred to as an umbrella partnership REIT or “UPREIT”. ​ The Company typically experiences seasonal fluctuations in the occupancy levels of its stores, which are generally slightly higher during the summer months due to increased moving activity. ​

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2021
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES ​ Basis of Presentation ​ The accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting and, in the opinion of each of the Parent Company’s and Operating Partnership’s respective management, include all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of financial position, results of operations and cash flows for each respective company for the interim periods presented in accordance with generally accepted accounting principles in the United States (“GAAP”). Accordingly, readers of this Quarterly Report on Form 10-Q should refer to the Parent Company’s and the Operating Partnership’s audited financial statements prepared in accordance with GAAP, and the related notes thereto, for the year ended December 31, 2020, which are included in the Parent Company’s and the Operating Partnership’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 ​ The Operating Partnership meets the criteria as a variable interest entity (“VIE”). The Parent Company’s sole significant asset is its investment in the Operating Partnership. As a result, substantially all of the Parent Company’s assets and liabilities represent those assets and liabilities of the Operating Partnership. All of the Parent Company’s debt is an obligation of the Operating Partnership, and the Parent Company guarantees the unsecured debt obligations of the Operating Partnership. ​ Recent Accounting Pronouncements ​ In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2020-06 – Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in an Entity’s Own Equity (Subtopic 815-40). The new guidance eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of certain settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted earnings per share computation. The standard is effective on January 1, 2022, with early adoption permitted, but only as of the beginning of an entity’s annual fiscal year. The standard is not expected to have a material impact on the Company’s consolidated financial statements.

STORAGE PROPERTIES

STORAGE PROPERTIES	3 Months Ended
	Mar. 31, 2021
STORAGE PROPERTIES
STORAGE FACILITIES	3. STORAGE PROPERTIES ​ The book value of the Company’s real estate assets is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 2020 ​ ​ ​ (in thousands) ​ Land ​ $ 1,100,598 ​ $ 1,093,503 ​ Buildings and improvements ​ 4,130,146 ​ 4,122,995 ​ Equipment ​ 120,871 ​ 123,044 ​ Construction in progress ​ 98,913 ​ 108,316 ​ Right-of-use assets - finance leases ​ ​ 41,655 ​ ​ 41,896 ​ Storage properties ​ 5,492,183 ​ 5,489,754 ​ Less: Accumulated depreciation ​ (997,712) ​ (983,940) ​ Storage properties, net ​ $ 4,494,471 ​ $ 4,505,814 ​ ​ The following table summarizes the Company’s acquisition and disposition activity during the period beginning on January 1, 2020 through March 31, 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Purchase / Sale Price Asset/Portfolio ​ Metropolitan Statistical Area ​ Transaction Date ​ Stores ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 Acquisitions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Texas Asset ​ San Antonio, TX ​ February 2020 ​ 1 ​ $ 9,025 ​ Maryland Asset ​ Baltimore-Towson, MD ​ April 2020 ​ 1 ​ ​ 17,200 ​ New Jersey Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ April 2020 ​ 1 ​ ​ 48,450 ​ Florida Asset ​ Palm Bay-Melbourne-Titusville, FL ​ November 2020 ​ 1 ​ ​ 3,900 ​ Texas Asset ​ Austin-Round Rock, TX ​ November 2020 ​ 1 ​ ​ 10,750 ​ Texas Asset ​ Dallas-Fort Worth-Arlington, TX ​ November 2020 ​ 1 ​ ​ 10,150 ​ Nevada Asset ​ Las Vegas-Paradise, NV ​ December 2020 ​ 1 ​ ​ 16,800 ​ New York Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 1 ​ ​ 6,750 ​ Florida Asset ​ Tampa-St. Petersburg-Clearwater, FL ​ December 2020 ​ 1 ​ ​ 10,000 ​ Virginia Asset ​ Washington-Arlington-Alexandria, DC-VA-MD-WV ​ December 2020 ​ 1 ​ ​ 17,350 ​ Storage Deluxe Assets ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 8 ​ ​ 540,000 ​ Florida Assets ​ Orlando-Kissimmee, FL / Deltona-Daytona Beach-Ormond Beach, FL ​ December 2020 ​ 3 ​ ​ 45,500 ​ ​ ​ ​ ​ ​ ​ 21 ​ $ 735,875 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 Disposition: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ New York Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 1 ​ $ 12,750 ​ ​ ​ ​ ​ ​ ​ 1 ​ $ 12,750 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

INVESTMENT ACTIVITY

INVESTMENT ACTIVITY	3 Months Ended
	Mar. 31, 2021
INVESTMENT ACTIVITY
INVESTMENT ACTIVITY	4. INVESTMENT ACTIVITY ​ The Company did not acquire or dispose of any wholly-owned stores during the three months ended March 31, 2021. ​ 2020 Acquisitions ​ The Company acquired a portfolio of eight stores located in the outer boroughs of New York City (the “Storage Deluxe Assets”), in two separate tranches during December 2020, for an aggregate purchase price of $540.0 million. In connection with the acquisition of the Storage Deluxe Assets, the Company assumed six mortgage loans with an aggregate outstanding principal amount of $154.4 million at the time of acquisition, one of which had an outstanding principal balance of $33.2 million and was repaid immediately. The assumed mortgage debt was recorded at a fair value of $169.2 million, which includes an aggregate net premium of $14.8 million to reflect the estimated fair value of the debt at the time of assumption. The remainder of the purchase price was funded with $210.5 million of cash and $175.1 million through the issuance of 5,272,023 OP Units (see note 13). In connection with the acquisition of the Storage Deluxe Assets, which was accounted for as an asset acquisition, the Company allocated the purchase price and acquisition related costs to the tangible and intangible assets acquired based on fair value. Intangible assets consisted of in-place leases, which aggregated to $48.6 million at the time of the acquisition and prior to amortization of such amounts. The estimated life of these in-place leases was 12 months and the amortization expense that was recognized during the three months ended March 31, 2021 was approximately $12.1 million. Additionally, as part of the transaction, the Company assumed three existing ground leases as lessee, two of which have been classified as finance leases and one of which has been classified as an operating lease (see note 14). ​ During the year ended December 31, 2020 the Company acquired 13 additional stores located in Florida (5) , Maryland (1) , Nevada (1) , New Jersey (1), New York (1) , Texas (3) and Virginia (1) for an aggregate purchase price of approximately $195.9 million. In connection with these transactions, which were accounted for as asset acquisitions, the Company allocated the purchase price and acquisition related costs to the tangible and intangible assets acquired based on fair value. Intangible assets consisted of in-place leases, which aggregated to $11.4 million at the time of the acquisitions and prior to amortization of such amounts. The estimated life of these in-place leases was 12 months and the amortization expense that was recognized during the three months ended March 31, 2021 and March 31, 2020 was approximately $2.8 million and thirty-two thousand dollars, respectively. ​ Additionally, on July 20, 2020, the Company acquired land underlying a wholly-owned store located in Bronx, New York for $9.5 million. The land was previously subject to a ground lease in which the Company served as lessee. As a result of the transaction, which was accounted for as an asset acquisition, the Company was released from its obligations under the ground lease, and the right-of-use asset and lease liability totaling $5.1 million and $5.0 million, respectively, were removed from the Company’s consolidated balance sheets. ​ 2020 Dispositions ​ On December 22, 2020, the Company sold a self-storage property located in New York for a sales price of $12.8 million. The Company recorded a $6.7 million gain in connection with the sale. ​ Development Activity ​ As of March 31, 2021, the Company had invested in joint ventures to develop five self-storage properties located in Massachusetts (1), New York (2), Pennsylvania (1) and Virginia (1). Construction for all projects is expected to be completed by the second quarter of 2022 (see note 13). As of March 31, 2021, development costs incurred to date for these projects totaled $85.7 million. Total construction costs for these projects are expected to be $124.3 million. These costs are capitalized to construction in progress while the projects are under development and are reflected in Storage properties on the Company’s consolidated balance sheets. ​ The Company has completed the construction and opened for operation the following stores during the period beginning on January 1, 2020 through March 31, 2021. The costs associated with the construction of these stores are capitalized to land, building and improvements, as well as equipment and are reflected in Storage properties on the Company’s consolidated balance sheets. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CubeSmart ​ ​ ​ ​ ​ Number of ​ ​ ​ Ownership ​ Total Store Location Stores Date Opened ​ Interest ​ Construction Costs ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Arlington, VA (1) ​ 1 ​ Q1 2021 ​ 90% ​ $ 26,400 Brooklyn, NY (2) ​ 1 ​ Q2 2020 ​ 100% ​ ​ 45,900 ​ ​ 2 ​ ​ ​ ​ ​ $ 72,300 ​ (1) This store is located adjacent to an existing consolidated joint venture store. Given their proximity to each other, the stores have been combined in our store count, as well as for operational and reporting purposes (see note 13). ​ (2) This store was previously owned by a consolidated joint venture, in which the Company held a 51% ownership interest. On September 29, 2020, the noncontrolling member in the venture that owned the store put its 49% interest in the venture to the Company for $10.0 million, of which $1.0 million was paid in cash. T he Company issued 276,497 OP Units that were valued at approximately $9.0 million as consideration for the remainder of the purchase price (see note 13).

INVESTMENT IN UNCONSOLIDATED RE

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	3 Months Ended
	Mar. 31, 2021
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	5. INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES ​ The Company’s investments in unconsolidated real estate ventures, in which it holds common ownership interests, are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CubeSmart ​ Number of Stores as of ​ Carrying Value of Investment as of ​ ​ Ownership ​ March 31, ​ December 31, ​ March 31, ​ December 31, Unconsolidated Real Estate Ventures Interest ​ 2021 ​ 2020 2021 ​ 2020 191 V CUBE LLC ("HVP V") (1) ​ 20% ​ 1 ​ - ​ $ 2,819 ​ $ - 191 IV CUBE Southeast LLC ("HVPSE") (2) ​ 10% ​ 14 ​ 14 ​ ​ 4,829 ​ ​ 5,015 191 IV CUBE LLC ("HVP IV") (3) ​ 20% ​ 22 ​ 21 ​ ​ 25,348 ​ ​ 21,760 CUBE HHF Northeast Venture LLC ("HHFNE") (4) ​ 10% ​ 13 ​ 13 ​ ​ 1,524 ​ ​ 1,628 CUBE HHF Limited Partnership ("HHF") (5) ​ 50% ​ 35 ​ 35 ​ ​ 59,277 ​ ​ 63,668 ​ ​ ​ ​ 85 ​ 83 ​ $ 93,797 ​ $ 92,071 ​ (1) On March 17, 2021, the Company invested a 20% ownership interest in a newly-formed real estate venture that acquired its initial self-storage property located in Florida. HVP V paid $14.0 million for this store, of which $0.9 million was allocated to the value of the in-place lease intangible. The purchase price was contributed pro-rata by the Company and its unaffiliated joint venture partner. The Company’s total contribution to HVP V related to this acquisition was $2.8 million. ​ (2) On March 19, 2020, the Company invested a 10% ownership interest in a newly-formed real estate venture that acquired 14 self-storage properties located in Florida (2) , Georgia (8) and South Carolina (4) . HVPSE paid $135.3 million for these stores, of which $7.7 million was allocated to the value of the in-place lease intangible. The acquisition was funded primarily through the venture’s $81.6 million secured term loan. The remainder of the purchase price was contributed pro-rata by the Company and its unaffiliated joint venture partner. The Company’s total contribution to HVPSE related to this portfolio acquisition was $5.6 million. The secured loan bears interest at LIBOR plus 1.60% and matures on March 19, 2023 with options to extend the maturity date through March 19, 2025, subject to satisfaction of certain conditions and payment of the extension fees as stipulated in the loan agreement. ​ (3) The stores owned by HVP IV are located in Arizona (2) , Connecticut (2) , Florida (4) , Georgia (2) , Maryland (2) , Minnesota (1) , Pennsylvania (1) and Texas (8) . The Company’s total contribution to HVP IV in connection with these store acquisitions was $30.1 million. As of March 31, 2021, HVP IV had $82.2 million outstanding on its $107.0 million secured loan facility, which bears interest at LIBOR plus 1.70% per annum, and matures on May 16, 2021. As of March 31, 2021, HVP IV also had $55.5 million outstanding under a separate secured loan that bears interest at LIBOR plus 2.75% per annum, and matures on June 9, 2022 with options to extend the maturity date through June 9, 2024, subject to satisfaction of certain conditions and payment of the extension fees as stipulated in the loan agreement. On April 19, 2021, HVP IV entered into a new secured loan and received $121.3 million in proceeds from the initial advance of the loan, which it used to repay the $82.2 million outstanding on its $107.0 million secured loan facility. The new secured loan bears interest at 1.95% over LIBOR and matures on April 19, 2025. ​ (4) The stores owned by HHFNE are located in Connecticut (3) , Massachusetts (6) , Rhode Island (2) and Vermont (2) . The Company’s total contribution to HHFNE in connection with these store acquisitions was $3.8 million. As of March 31, 2021, HHFNE had an outstanding $45.0 million secured loan facility, which bears interest at LIBOR plus 1.20% per annum and matures on December 16, 2024. ​ (5) The stores owned by HHF are located in North Carolina (1) and Texas (34) . On January 21, 2021, HHF entered into a new $105.0 million secured loan, which bears interest at 2.58% per annum and matures on February 5, 2028. HHF used the proceeds from this loan to repay its existing outstanding $100.0 million loan in full. ​ Based upon the facts and circumstances at formation of HVP V, HVPSE, HVP IV, HHFNE and HHF (the “Ventures”), the Company determined that the Ventures are not VIEs in accordance with the accounting standard for the consolidation of VIEs. As a result, the Company used the voting interest model under the accounting standard for consolidation in order to determine whether to consolidate the Ventures. Based upon each member's substantive participating rights over the activities of each entity as stipulated in the operating agreements, the Ventures are not consolidated by the Company and are accounted for under the equity method of accounting. The Company’s investments in the Ventures are included in Investment in real estate ventures, at equity on the Company’s consolidated balance sheets and the Company’s earnings from its investments in the Ventures are presented in Equity in earnings (losses) of real estate ventures on the Company’s consolidated statements of operations. ​ The amounts reflected in the following table are based on the historical financial information of the Ventures. ​ The following is a summary of the financial position of the Ventures as of March 31, 2021 and December 31, 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 2020 (1) Assets ​ (in thousands) Storage properties, net ​ $ 686,849 ​ $ 662,833 Other assets ​ 22,924 ​ 18,112 Total assets ​ $ 709,773 ​ $ 680,945 ​ ​ ​ ​ ​ ​ ​ Liabilities and equity ​ ​ ​ ​ ​ ​ Debt ​ $ 367,547 ​ $ 359,985 Other liabilities ​ ​ 12,494 ​ ​ 11,588 Equity ​ ​ ​ ​ ​ ​ CubeSmart ​ 93,797 ​ ​ 92,071 Joint venture partners ​ 235,935 ​ ​ 217,301 Total liabilities and equity ​ $ 709,773 ​ $ 680,945 ​ ​ ​ ​ ​ ​ ​ (1) Excludes HVP V as it acquired its initial asset on March 17, 2021. ​ The following is a summary of results of operations of the Ventures for the three months ended March 31, 2021 and 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2021 (1) 2020 (2) ​ ​ (in thousands) ​ Total revenues ​ $ 18,823 ​ $ 14,605 ​ ​ Operating expenses ​ (8,605) ​ ​ (6,942) ​ ​ Other income (expenses) ​ ​ 3 ​ ​ (113) ​ ​ Interest expense, net ​ (3,535) ​ ​ (2,720) ​ ​ Depreciation and amortization ​ (8,713) ​ (6,423) ​ ​ Net loss ​ $ (2,027) ​ $ (1,593) ​ ​ Company’s share of net income (loss) ​ $ 20 ​ $ (5) ​ ​ ​ ​ ​ ​ (1) Represents a partial quarter of HVP V as it acquired its initial asset on March 17, 2021. ​ (2) Excludes HVP V as it acquired its initial asset on March 17, 2021 and represents a partial quarter of HVPSE as it acquired its initial assets on March 19, 2020. ​

OTHER ASSETS

OTHER ASSETS	3 Months Ended
	Mar. 31, 2021
Other Assets, Unclassified [Abstract]
OTHER ASSETS	6. OTHER ASSETS ​ Other assets are comprised of the following as of March 31, 2021 and December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 ​ ​ (in thousands) Intangible assets, net of accumulated amortization of $16,688 and $2,123 ​ $ 42,867 ​ $ 57,820 Accounts receivable, net ​ 5,313 ​ 5,829 Prepaid property taxes ​ 5,403 ​ 6,334 Prepaid property and casualty insurance ​ 1,540 ​ 2,626 Amounts due from affiliates (see note 15) ​ ​ 15,048 ​ ​ 13,130 Assets held in trust related to deferred compensation arrangements ​ ​ 19,345 ​ ​ 17,207 Right-of-use assets - operating leases (see note 14) ​ ​ 54,989 ​ ​ 55,302 Equity investment recorded at cost (1) ​ ​ 5,000 ​ ​ 5,000 Other ​ 7,684 ​ 7,505 Total other assets, net ​ $ 157,189 ​ $ 170,753 ​ (1) On September 5, 2018, the Company invested $5.0 million in exchange for 100% of the Class A preferred units of Capital Storage Partners, LLC (“Capital Storage”), a newly formed venture that acquired 22 self-storage properties located in Florida (4) , Oklahoma (5) and Texas (13) . The Class A preferred units earn an 11% cumulative dividend prior to any other distributions. The Company’s investment in Capital Storage and the related dividends are included in Other assets, net on the Company’s consolidated balance sheets and in Other income on the Company’s consolidated statements of operations, respectively.

UNSECURED SENIOR NOTES

UNSECURED SENIOR NOTES	3 Months Ended
	Mar. 31, 2021
UNSECURED SENIOR NOTES
UNSECURED SENIOR NOTES	7. UNSECURED SENIOR NOTES ​ The Company’s unsecured senior notes are summarized as follows (collectively referred to as the “Senior Notes”): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Effective ​ Issuance ​ Maturity Unsecured Senior Notes 2021 2020 Interest Rate ​ Date ​ Date ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ $300M 4.375% Guaranteed Notes due 2023 (1) ​ $ 300,000 ​ $ 300,000 4.33 % ​ Various (1) ​ Dec-23 ​ $300M 4.000% Guaranteed Notes due 2025 (2) ​ 300,000 ​ 300,000 3.99 % ​ Various (2) ​ Nov-25 ​ $300M 3.125% Guaranteed Notes due 2026 ​ ​ 300,000 ​ ​ 300,000 ​ 3.18 % ​ Aug-16 ​ Sep-26 ​ $350M 4.375% Guaranteed Notes due 2029 ​ ​ 350,000 ​ ​ 350,000 ​ 4.46 % ​ Jan-19 ​ Feb-29 ​ $350M 3.000% Guaranteed Notes due 2030 ​ ​ 350,000 ​ ​ 350,000 ​ 3.04 % ​ Oct-19 ​ Feb-30 ​ $450M 2.000% Guaranteed Notes due 2031 ​ ​ 450,000 ​ ​ 450,000 ​ 2.10 % ​ Oct-20 ​ Feb-31 ​ Principal balance outstanding ​ ​ 2,050,000 ​ ​ 2,050,000 ​ ​ ​ ​ ​ ​ ​ ​ Less: Discount on issuance of unsecured senior notes, net ​ ​ (7,278) ​ ​ (7,470) ​ ​ ​ ​ ​ ​ ​ ​ Less: Loan procurement costs, net ​ ​ (11,723) ​ ​ (12,158) ​ ​ ​ ​ ​ ​ ​ ​ Total unsecured senior notes, net ​ $ 2,030,999 ​ $ 2,030,372 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) On April 4, 2017, the Operating Partnership issued $50.0 million of its 4.375% senior notes due 2023, which are part of the same series as the $250.0 million principal amount of the Operating Partnership’s 4.375% senior notes due December 15, 2023 issued on December 17, 2013. The $50.0 million and $250.0 million tranches were priced at 105.040% and 98.995% , respectively, of the principal amount to yield 3.495% and 4.501% , respectively, to maturity. The combined weighted average effective interest rate of the 2023 notes is 4.330% . ​ (2) On April 4, 2017, the Operating Partnership issued $50.0 million of its 4.000% senior notes due 2025, which are part of the same series as the $250.0 million principal amount of the Operating Partnership’s 4.000% senior notes due November 15, 2025 issued on October 26, 2015. The $50.0 million and $250.0 million tranches were priced at 101.343% and 99.735% , respectively, of the principal amount to yield 3.811% and 4.032% , respectively, to maturity. The combined weighted average effective interest rate of the 2025 notes is 3.994% . ​ The indenture under which the Senior Notes were issued restricts the ability of the Operating Partnership and its subsidiaries to incur debt unless the Operating Partnership and its consolidated subsidiaries comply with a leverage ratio not to exceed 60% and an interest coverage ratio of more than 1.5 :1.0 after giving effect to the incurrence of the debt. The indenture also restricts the ability of the Operating Partnership and its subsidiaries to incur secured debt unless the Operating Partnership and its consolidated subsidiaries comply with a secured debt leverage ratio not to exceed 40% after giving effect to the incurrence of the debt. The indenture also contains other financial and customary covenants, including a covenant not to own unencumbered assets with a value less than 150% of the unsecured indebtedness of the Operating Partnership and its consolidated subsidiaries. As of March 31, 2021, the Operating Partnership was in compliance with all of the financial covenants under the Senior Notes.

REVOLVING CREDIT FACILITY

REVOLVING CREDIT FACILITY	3 Months Ended
	Mar. 31, 2021
REVOLVING CREDIT FACILITY
REVOLVING CREDIT FACILITY AND UNSECURED TERM LOANS	8. REVOLVING CREDIT FACILITY ​ On December 9, 2011, the Company entered into a credit agreement (the “Credit Facility”). On June 19, 2019, the Company amended and restated, in its entirety, the Credit Facility (the “Amended and Restated Credit Facility”) which, subsequent to the amendment and restatement, is comprised of a $750.0 million unsecured revolving facility (the “Revolver”) maturing on June 19, 2024. Under the Amended and Restated Credit Facility, pricing on the Revolver is dependent upon the Company’s unsecured debt credit ratings. At the Company’s current Baa2/BBB level, amounts drawn under the Revolver are priced at 1.10% over LIBOR, inclusive of a facility fee of 0.15%. ​ As of March 31, 2021, borrowings under the Revolver had an effective interest rate of 1.21%. Additionally, as of March 31, 2021, $696.6 million was available for borrowing under the Revolver. The available balance under the Revolver is reduced by an outstanding letter of credit of $0.6 million. ​ Under the Amended and Restated Credit Facility, the Company’s ability to borrow under the Revolver is subject to ongoing compliance with certain financial covenants which include, among other things, (1) a maximum total indebtedness to total asset value of 60.0%, and (2) a minimum fixed charge coverage ratio of 1.5:1.0. As of March 31, 2021, the Company was in compliance with all of its financial covenants.

MORTGAGE LOANS AND NOTES PAYABL

MORTGAGE LOANS AND NOTES PAYABLE	3 Months Ended
	Mar. 31, 2021
MORTGAGE LOANS AND NOTES PAYABLE
MORTGAGE LOANS AND NOTES PAYABLE	9. MORTGAGE LOANS AND NOTES PAYABLE ​ The Company’s mortgage loans and notes payable are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Value as of ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Effective ​ Maturity Mortgage Loans and Notes Payable 2021 2020 Interest Rate ​ Date ​ ​ (in thousands) ​ ​ ​ ​ ​ Bronx IX, NY (1) ​ $ — ​ $ 21,030 4.85 % ​ Jun-21 ​ Bronx X, NY (1) ​ — ​ 23,148 4.64 % ​ Jun-21 ​ Nashville V, TN ​ ​ 2,247 ​ ​ 2,261 ​ 3.85 % ​ Jun-23 ​ New York, NY ​ ​ 29,819 ​ ​ 29,981 ​ 3.51 % ​ Jun-23 ​ Annapolis I, MD ​ ​ 5,238 ​ ​ 5,283 ​ 3.78 % ​ May-24 ​ Brooklyn XV, NY ​ ​ 15,658 ​ ​ 15,713 ​ 2.15 % ​ May-24 ​ Long Island City IV, NY ​ ​ 12,801 ​ ​ 12,852 ​ 2.15 % ​ May-24 ​ Long Island City II, NY ​ ​ 19,034 ​ ​ 19,094 ​ 2.25 % ​ Jul-26 ​ Long Island City III, NY ​ ​ 19,022 ​ ​ 19,106 ​ 2.25 % ​ Aug-26 ​ Flushing II, NY ​ ​ 54,300 ​ ​ 54,300 ​ 2.15 % ​ Jul-29 ​ Principal balance outstanding ​ ​ 158,119 ​ ​ 202,768 ​ ​ ​ ​ ​ ​ Plus: Unamortized fair value adjustment ​ ​ 15,080 ​ 15,879 ​ ​ ​ ​ ​ ​ Less: Loan procurement costs, net ​ ​ (2,010) ​ ​ (2,143) ​ ​ ​ ​ ​ ​ Total mortgage loans and notes payable, net ​ $ 171,189 ​ $ 216,504 ​ ​ ​ ​ ​ ​ ​ (1) These mortgage loans were repaid in full on March 1, 2021. ​ As of March 31, 2021 and December 31, 2020, the Company’s mortgage loans payable were secured by certain of its self-storage properties with net book values of approximately $457.0 million and $539.2 million, respectively. The following table represents the future principal payment requirements on the outstanding mortgage loans and notes payable as of March 31, 2021 (in thousands): ​ ​ ​ ​ ​ 2021 $ 1,733 2022 ​ 2,426 2023 ​ 32,591 2024 ​ 32,329 2025 ​ 979 2026 and thereafter ​ 88,061 Total mortgage payments ​ 158,119 Plus: Unamortized fair value adjustment ​ 15,080 Less: Loan procurement costs, net ​ ​ (2,010) Total mortgage loans and notes payable, net ​ $ 171,189 ​

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	3 Months Ended
	Mar. 31, 2021
ACCUMULATED OTHER COMPREHENSIVE LOSS
ACCUMULATED OTHER COMPREHENSIVE LOSS	10. ACCUMULATED OTHER COMPREHENSIVE LOSS ​ The following table summarizes the changes in accumulated other comprehensive loss by component for the three months ended March 31, 2021 (in thousands): ​ ​ ​ ​ ​ March 31, ​ 2021 ​ ​ (in thousands) Beginning balance $ (656) Reclassification of realized losses on interest rate swaps (1) ​ 20 Ending balance ​ (636) Less: portion included in noncontrolling interests in the Operating Partnership ​ 23 Total accumulated other comprehensive loss included in equity $ (613) ​ (1) See note 11 for additional information about the effects of the amounts reclassified.

RISK MANAGEMENT AND USE OF FINA

RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2021
RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS
RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS	11. RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS ​ The Company’s use of derivative instruments is limited to the utilization of interest rate swap agreements or other instruments to manage interest rate risk exposure and not for speculative purposes. The principal objective of such arrangements is to minimize the risks and/or costs associated with the Company’s operating and financial structure, as well as to hedge specific transactions. The counterparties to these arrangements are major financial institutions with which the Company and its subsidiaries may also have other financial relationships. The Company is potentially exposed to credit loss in the event of non-performance by these counterparties. However, because of the high credit ratings of the counterparties, the Company does not anticipate any of the counterparties will fail to meet these obligations as they come due. The Company does not hedge credit or property value market risks. ​ The Company formally assesses, both at inception of a hedge and on an on-going basis, whether each derivative is highly-effective in offsetting changes in cash flows of the hedged item. If management determines that the derivative is highly-effective as a hedge, then the Company accounts for the derivative using hedge accounting, pursuant to which gains or losses inherent in the derivative do not impact the Company’s results of operations. If management determines that the derivative is not highly-effective as a hedge or if a derivative ceases to be a highly-effective hedge, the Company discontinues hedge accounting prospectively and reflects in its statement of operations realized and unrealized gains and losses with respect to the derivative. As of March 31, 2021 and December 31, 2020, all derivative instruments entered into by the Company had been settled. ​ On December 24, 2018, the Company entered into interest rate swap agreements with notional amounts that aggregated to $150.0 million (the “Interest Rate Swaps”) to protect the Company against adverse fluctuations in interest rates by reducing exposure to variability in cash flows relating to interest payments on a forecasted issuance of long-term debt. The Interest Rate Swaps qualified and were designated as cash flow hedges. Accordingly, the Interest Rate Swaps were recorded on the consolidated balance sheet at fair value and the related gains or losses were deferred in shareholders’ equity as accumulated other comprehensive income or loss. These deferred gains and losses were amortized into interest expense during the period or periods in which the related interest payments affected earnings. On January 24, 2019, in conjunction with the issuance of the 2029 Notes, the Company settled the Interest Rate Swaps for $0.8 million. The $0.8 million termination premium will be reclassified from accumulated other comprehensive loss as an increase to interest expense over the life of the 2029 Notes, which mature on February 15, 2029. The change in unrealized losses on interest rate swaps reflects a reclassification of twenty thousand dollars of unrealized losses from accumulated other comprehensive loss as an increase to interest expense during the three months ended March 31, 2021. The Company estimates that $0.1 million will be reclassified as an increase to interest expense in the next 12 months.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	12. FAIR VALUE MEASUREMENTS ​ The Company applies the methods of determining fair value as described in authoritative guidance, to value its financial assets and liabilities. As defined in the guidance, fair value is based on the price that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In order to increase consistency and comparability in fair value measurements, the guidance establishes a fair value hierarchy that prioritizes observable and unobservable inputs used to measure fair value into three broad levels, which are described below: ​ Level 1: Quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities. The fair value hierarchy gives the highest priority to Level 1 inputs. ​ Level 2: Observable prices that are based on inputs not quoted on active markets, but corroborated by market data. ​ Level 3: Unobservable inputs are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs. ​ In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs, to the extent possible, as well as considering counterparty credit risk in its assessment of fair value. ​ There were no financial assets or liabilities carried at fair value as of March 31, 2021 or December 31, 2020. ​ The fair values of financial instruments, including cash and cash equivalents, restricted cash, accounts receivable and accounts payable approximate their respective carrying values at March 31, 2021 and December 31, 2020. ​ The following table summarizes the carrying value and estimated fair value of the Company’s debt as of March 31, 2021 and December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 ​ ​ (in thousands) Carrying value $ 2,254,988 ​ $ 2,364,676 Fair value ​ 2,348,913 ​ ​ 2,571,300 ​ The fair value of debt estimates were based on a discounted cash flow analysis assuming market interest rates for comparable obligations at March 31, 2021 and December 31, 2020. The Company estimates the fair value of its fixed-rate debt and the credit spreads over variable market rates on its variable-rate debt by discounting the future cash flows of each instrument at estimated market rates or credit spreads consistent with the maturity of the debt obligation with similar credit policies, which is classified within level 2 of the fair value hierarchy. Rates and credit spreads take into consideration general market conditions and maturity.

NONCONTROLLING INTERESTS

NONCONTROLLING INTERESTS	3 Months Ended
	Mar. 31, 2021
NONCONTROLLING INTERESTS
NONCONTROLLING INTERESTS	13. NONCONTROLLING INTERESTS ​ Interests in Consolidated Joint Ventures ​ Noncontrolling interests in subsidiaries represent the ownership interests of third parties in the Company’s consolidated real estate ventures. The Company has determined that these ventures are VIEs, and that the Company is the primary beneficiary. Accordingly, the Company consolidates the assets, liabilities and results of operations of the real estate ventures in the table below (dollars in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Date Opened / ​ CubeSmart ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ ​ ​ Estimated ​ Ownership ​ March 31, 2021 ​ Consolidated Joint Ventures of Stores Location Opening ​ Interest ​ Total Assets ​ Total Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ CS Vienna, LLC ("Vienna") (1) ​ 1 ​ Vienna, VA ​ Q2 2022 (est.) ​ 72% ​ $ 17,865 ​ $ 6,553 ​ CS 750 W Merrick Rd, LLC ("Merrick") (2) ​ 1 ​ Valley Stream, NY ​ Q1 2022 (est.) ​ 51% ​ ​ 15,626 ​ ​ 8,181 ​ CS Valley Forge Village Storage, LLC ("VFV") (3) ​ 1 ​ King of Prussia, PA ​ Q2 2021 (est.) ​ 70% ​ ​ 20,654 ​ ​ 12,333 ​ CS 2087 Hempstead Tpk, LLC ("Hempstead") (2) ​ 1 ​ East Meadow, NY ​ Q2 2021 (est.) ​ 51% ​ ​ 24,336 ​ ​ 7,104 ​ CS SDP Newtonville, LLC ("Newton") (3) ​ 1 ​ Newton, MA ​ Q2 2021 (est.) ​ 90% ​ ​ 18,345 ​ ​ 11,828 ​ SH3, LLC ("SH3") (4) ​ 1 ​ Arlington, VA Q2 2015/Q1 2021 ​ 90% ​ ​ 39,659 ​ ​ 6,667 ​ ​ ​ 6 ​ ​ ​ ​ ​ ​ ​ $ 136,485 ​ $ 52,666 ​ ​ (1) On December 23, 2020, the Company and the noncontrolling member contributed a previously wholly-owned operating property (the “Vienna Operating Property”) and a parcel of land (the “Vienna Land”), respectively, to Vienna. The Vienna Operating Property and the Vienna Land are located in close proximity to each other in Vienna, VA. The members intend to construct a new store on the Vienna Land, which, upon completion, will be combined with the Vienna Operating Property and operated by the venture as a single store. The Company has a related party commitment to Vienna to fund all or a portion of the construction costs. As of March 31, 2021, the Company has funded $ 5.4 million of a total $17.0 million loan commitment to Vienna, which is included in the total liabilities amount within the table above. This loan and the related interest were eliminated for consolidation purposes. ​ (2) The noncontrolling members of Merrick and Hempstead have the option to put their ownership interest in the ventures to the Company for $17.1 million and $6.6 million (the “Put Option”), respectively, within the two-year period after construction of each store is substantially complete (the “Put Option Period”). In the event the Put Option is not exercised, the Company has a one-year option to call the ownership interest of the noncontrolling members of Merrick and Hempstead for $17.1 million and $6.6 million, respectively, beginning twelve months after the end of the Put Option Period. The Company, at its sole discretion, may pay cash and/or issue OP Units, in exchange for the noncontrolling member’s interest in Merrick and Hempstead. The Company is accreting the respective liabilities during the development periods and, as of March 31, 2021, has accrued $7.3 million and $6.2 million, related to Merrick and Hempstead, respectively, which are included in Accounts payable, accrued expenses and other liabilities on the Company’s consolidated balance sheets. ​ (3) The Company has related party loan commitments to VFV and Newton to fund a portion of the construction costs. As of March 31, 2021, the Company has funded $9.6 million of the total $12.4 million loan commitment to VFV and $11.1 million of the total $12.1 million loan commitment to Newton, which are included in the total liability amounts within the table above. These loans and the related interest were eliminated for consolidation purposes. ​ (4) SH3 owns two stores located in close proximity to each other in Arlington, VA, the first of which was developed and opened for operation in April 2015 (“Shirlington I”) and the second of which was developed and opened for operation in March 2021 (“Shirlington II”). Given their close proximity to each other, the two stores were combined in our store count, as well as for operational and reporting purposes, upon the opening of Shirlington II in March 2021. ​ Operating Partnership Ownership ​ The Company follows guidance regarding the classification and measurement of redeemable securities. Under this guidance, securities that are redeemable for cash or other assets, at the option of the holder and not solely within the control of the issuer, must be classified outside of permanent equity/capital. This classification results in certain outside ownership interests being included as redeemable noncontrolling interests outside of permanent equity/capital in the consolidated balance sheets. The Company makes this determination based on terms in applicable agreements, specifically in relation to redemption provisions. ​ Additionally, with respect to redeemable ownership interests in the Operating Partnership held by third parties for which CubeSmart has a choice to settle the redemption by delivery of its own shares, the Operating Partnership considered the guidance regarding accounting for derivative financial instruments indexed to, and potentially settled in, a company’s own shares, to evaluate whether CubeSmart controls the actions or events necessary to presume share settlement. The guidance also requires that noncontrolling interests classified outside of permanent capital be adjusted each period to the greater of the carrying value based on the accumulation of historical cost or the redemption value. ​ Approximately 3.5% and 3.6% of the outstanding OP Units, as of March 31, 2021 and December 31, 2020 were not owned by CubeSmart, the sole general partner. The interests in the Operating Partnership represented by these OP Units were a component of the consideration that the Operating Partnership paid to acquire certain self-storage properties. The holders of the OP Units are limited partners in the Operating Partnership and have the right to require CubeSmart to redeem all or part of their OP Units for, at the general partner’s option, an equivalent number of common shares of CubeSmart or cash based upon the fair value of an equivalent number of common shares of CubeSmart. However, the partnership agreement contains certain provisions that could result in a settlement outside the control of CubeSmart and the Operating Partnership, as CubeSmart does not have the ability to settle in unregistered shares. Accordingly, consistent with the guidance, the Operating Partnership will record the OP Units owned by third parties outside of permanent capital in the consolidated balance sheets. Net income or loss related to the OP Units owned by third parties is excluded from net income or loss attributable to Operating Partner in the consolidated statements of operations. ​ In two separate tranches during December 2020, the Company acquired the Storage Deluxe Assets for an aggregate purchase price of $540.0 million. In connection with the acquisition of the Storage Deluxe Assets, the Company issued 5,272,023 OP Units valued at approximately $175.1 million to fund a portion of the purchase price. ​ On September 29, 2020, the Company acquired the noncontrolling interest in a previously consolidated joint venture that owned a store in New York for $10.0 million. In conjunction with the closing, the Company paid $1.0 million in cash and issued 276,497 OP Units, valued at approximately $9.0 million, to pay the remaining consideration. ​ As of March 31, 2021 and December 31, 2020, 7,365,828 and 7,420,828 OP units, respectively, were held by third parties. The per unit cash redemption amount of the outstanding OP units was calculated based upon the closing price of the common shares of CubeSmart on the New York Stock Exchange on the final trading day of the quarter. Based on the Company’s evaluation of the redemption value of the redeemable noncontrolling interest, the Company has reflected these interests at the greater of the carrying value based on the accumulation of historical cost or the redemption value at March 31, 2021 and December 31, 2020. As of March 31, 2021 and December 31, 2020, the Operating Partnership recorded an increase in the value of OP Units owned by third parties and a corresponding decrease to capital of $32.1 million and $4.2 million, respectively.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2021
LEASES
LEASES	14. LEASES ​ CubeSmart as Lessor ​ The Company derives revenue primarily from rents received from customers who rent cubes at its self-storage properties under month-to-month leases for personal or business use. The self-storage lease agreements utilized by the Company vary slightly to comply with state-specific laws and regulations, but, subject to such laws and regulations, generally provide for automatic monthly renewals, flexibility to increase rental rates over time as market conditions permit and the collection of contingent fees such as administrative and late fees. None of the self-storage lease agreements contain options that allow the customer to purchase the leased space at any time during, or at the expiration of, the lease term. All self-storage leases in which the Company serves as lessor have been classified as operating leases. Accordingly, storage cubes are carried at historical cost less accumulated depreciation and impairment, if any, and are included in Storage properties on the Company’s consolidated balance sheets. Operating lease income for amounts received under the Company’s self-storage lease agreements is recognized on a straight-line basis which, due to the month-to-month nature of the leases, results in the recognition of income during the initial term and each subsequent monthly renewal using the then-in-place rent amount. Operating lease income is included in Rental income within the Company’s consolidated statements of operations. Variable lease income related to the Company’s self-storage lease agreements consists of administrative and late fees charged to customers. For the three months ended March 31, 2021 and 2020, administrative and late fees totaled $4.8 million and $5.4 million, respectively. Administrative and late fees are included in Other property related income within the Company’s consolidated statements of operations. ​ CubeSmart as Lessee ​ The Company serves as lessee in lease agreements for land, office space, automobiles and certain equipment, which have remaining lease terms of up to 44 years . Certain of the Company’s leases (1) provide for one or more options to renew, with renewal options that can extend the lease up to 69 years , (2) allow for early termination at certain points during the lease term and/or (3) give the Company the option to purchase the leased property. In all cases, the exercise of the lease renewal, termination and purchase options, if provided for in the lease, are at the Company’s sole discretion. Certain of the Company’s lease agreements, particularly its land leases, require rental payments that are periodically adjusted for inflation using a defined index. None of the Company’s lease agreements contain any material residual value guarantees or material restrictive covenants. Lease expense for payments related to the Company’s finance leases is recognized as interest expense using the interest method over the related lease term. Lease expense for payments related to the Company’s operating leases is recognized on a straight-line basis over the related lease term, which includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. ​ Right-of-use assets represent the Company’s right to use an underlying asset during the lease term and lease liabilities represent the Company’s obligation to make lease payments as specified in the lease. Right-of-use assets and lease liabilities related to the Company’s operating leases are recognized at the lease commencement date based on the present value of the remaining lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available surrounding the Company’s unsecured borrowing rates and implied secured spread at the lease commencement date in determining the present value of lease payments. The right-of-use asset also includes any lease payments made at or before lease commencement less any lease incentives. ​ For the three months ended March 31, 2021 and 2020, the Company’s lease cost consists of the following components: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ ​ 2021 2020 ​ ​ ​ ​ (in thousands) Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ Amortization of finance lease right-of-use assets ​ $ 241 ​ $ — ​ ​ Interest expense related to finance lease liabilities ​ ​ 526 ​ ​ — ​ ​ Operating lease cost ​ ​ 822 ​ ​ 746 ​ ​ Short-term lease cost (1) ​ 306 ​ ​ 308 ​ ​ Total lease cost ​ $ 1,895 ​ $ 1,054 ​ ​ ​ (1) Represents automobile leases that have a lease term of 12 months . The Company has made an accounting policy election not to apply the recognition requirements of ASC 842 to this asset class. The lease cost associated with these leases is recognized on a straight-line basis over the related lease term. ​ The following table represents supplemental balance sheet information related to leases as of March 31, 2021 and December 31, 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ ​ (dollars in thousands) ​ Finance Leases ​ ​ ​ ​ ​ ​ ​ Right-of-use assets included in Storage properties, net ​ $ 41,655 ​ $ 41,896 ​ Lease liabilities included in Lease liabilities - finance leases ​ $ 65,710 ​ $ 65,599 ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases ​ ​ ​ ​ ​ ​ ​ Right-of-use assets included in Other assets, net ​ $ 54,989 ​ $ 55,302 ​ Lease liabilities included in Accounts payable, accrued expenses and other liabilities ​ $ 53,541 ​ $ 53,595 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Lease Term (in years) ​ ​ ​ ​ ​ ​ ​ Finance leases ​ ​ 43.3 ​ ​ 43.5 ​ Operating leases ​ ​ 34.6 ​ ​ 34.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Discount Rate ​ ​ ​ ​ ​ ​ ​ Finance leases ​ ​ 3.25 % ​ 3.25 % Operating leases ​ ​ 4.47 % ​ 4.46 % ​ The following table represents the future lease liability maturities as of March 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating 2021 $ 1,520 $ 1,893 2022 ​ 2,183 ​ 2,639 2023 ​ 2,183 ​ 2,690 2024 ​ 2,183 ​ 2,540 2025 ​ 2,224 ​ 2,539 2026 and thereafter ​ 122,932 ​ 99,290 Total lease payments ​ 133,225 ​ 111,591 Less: Imputed interest ​ ​ (67,515) ​ ​ (58,050) Present value of lease liabilities ​ $ 65,710 ​ $ 53,541 ​ ​ ​ ​ ​ ​ ​ ​ During the three months ended March 31, 2021 and 2020, the cash paid for amounts included in the measurement of lease liabilities related to the Company’s operating leases was approximately $0.5 million and $0.6 million, respectively. During the three months ended March 31, 2021, the cash paid for amounts included in the measurement of lease liabilities related to the Company’s finance leases was approximately $0.4 million. There were no such payments during the three months ended March 31, 2020. These amounts are included as operating cash outflows within the consolidated statements of cash flows. During the three months ended March 31, 2021 and 2020, the Company did not enter into any lease agreements set to commence in the future.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	15. COMMITMENTS AND CONTINGENCIES ​ The Company is involved in claims from time to time, which arise in the ordinary course of business. In accordance with applicable accounting guidance, management establishes an accrued liability for claim expenses, insurance retention and litigation costs when those matters present loss contingencies that are both probable and reasonably estimable. In such cases, there may be exposure to loss in excess of those amounts accrued. The estimated loss, if any, is based upon currently available information and is subject to significant judgment, a variety of assumptions, and known and unknown uncertainties. In the opinion of management, the Company has made adequate provisions for potential liabilities, arising from any such matters, which are included in Accounts payable, accrued expenses and other liabilities on the Company’s consolidated balance sheets.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2021
RELATED PARTY TRANSACTIONS
RELATED PARTY TRANSACTIONS	16. RELATED PARTY TRANSACTIONS ​ The Company provides management services to certain joint ventures and other related parties. Management agreements provide for fee income to the Company based on a percentage of revenues at the managed stores. Total management fees for unconsolidated real estate ventures or other entities in which the Company held an ownership interest for the three months ended March 31, 2021 and 2020 totaled $1.0 million and $0.9 million, respectively. ​ The management agreements for certain joint ventures, other related parties and third-party stores provide for the reimbursement to the Company for certain expenses incurred to manage the stores. These amounts consist of amounts due for management fees, payroll, and other store expenses. The amounts due to the Company were $15.0 million and $13.1 million as of March 31, 2021 and December 31, 2020, respectively, and are reflected in Other assets, net on the Company’s consolidated balance sheets. Additionally, as discussed in note 13, the Company had outstanding mortgage loans receivable from consolidated joint ventures of $26.2 million and $21.4 million as of March 31, 2021 and December 31, 2020, respectively, which are eliminated for consolidation purposes. The Company believes that all of these related-party receivables are fully collectible. ​ The HVP V, HVPSE, HVP IV and HHFNE operating agreements provide for acquisition, disposition and other fees payable from HVP V, HVPSE, HVP IV and HHFNE to the Company upon the closing of a property transaction by HVP V, HVPSE, HVP IV and HHFNE or any of their subsidiaries and completion of certain measures as defined in the operating agreements. During the three months ended March 31, 2021 and 2020, the Company recognized fees associated with property transactions of $0.2 million and $0.7 million, respectively. Property transaction fees are included in Other income on the consolidated statements of operations. ​

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	17. SUBSEQUENT EVENTS ​ On April 16, 2021, the Company contributed $3.4 million to acquire a 50% interest in a joint venture that owns a self-storage property located in Minnesota. In addition, the Company has a $6.1 million related party loan commitment to the joint venture, of which $5.5 million was funded in conjunction with the membership interest acquisition.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) 10K	3 Months Ended
	Mar. 31, 2021
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Basis of Presentation	Basis of Presentation ​ The accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting and, in the opinion of each of the Parent Company’s and Operating Partnership’s respective management, include all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of financial position, results of operations and cash flows for each respective company for the interim periods presented in accordance with generally accepted accounting principles in the United States (“GAAP”). Accordingly, readers of this Quarterly Report on Form 10-Q should refer to the Parent Company’s and the Operating Partnership’s audited financial statements prepared in accordance with GAAP, and the related notes thereto, for the year ended December 31, 2020, which are included in the Parent Company’s and the Operating Partnership’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 ​ The Operating Partnership meets the criteria as a variable interest entity (“VIE”). The Parent Company’s sole significant asset is its investment in the Operating Partnership. As a result, substantially all of the Parent Company’s assets and liabilities represent those assets and liabilities of the Operating Partnership. All of the Parent Company’s debt is an obligation of the Operating Partnership, and the Parent Company guarantees the unsecured debt obligations of the Operating Partnership.
Recent Accounting Pronouncements	Recent Accounting Pronouncements ​ In August 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2020-06 – Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in an Entity’s Own Equity (Subtopic 815-40). The new guidance eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of certain settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted earnings per share computation. The standard is effective on January 1, 2022, with early adoption permitted, but only as of the beginning of an entity’s annual fiscal year. The standard is not expected to have a material impact on the Company’s consolidated financial statements.

STORAGE PROPERTIES (Tables)

STORAGE PROPERTIES (Tables)	3 Months Ended
	Mar. 31, 2021
STORAGE PROPERTIES
Summary of real estate assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 2020 ​ ​ ​ (in thousands) ​ Land ​ $ 1,100,598 ​ $ 1,093,503 ​ Buildings and improvements ​ 4,130,146 ​ 4,122,995 ​ Equipment ​ 120,871 ​ 123,044 ​ Construction in progress ​ 98,913 ​ 108,316 ​ Right-of-use assets - finance leases ​ ​ 41,655 ​ ​ 41,896 ​ Storage properties ​ 5,492,183 ​ 5,489,754 ​ Less: Accumulated depreciation ​ (997,712) ​ (983,940) ​ Storage properties, net ​ $ 4,494,471 ​ $ 4,505,814 ​
Schedule of acquisitions and dispositions of real estate assets	The following table summarizes the Company’s acquisition and disposition activity during the period beginning on January 1, 2020 through March 31, 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Purchase / Sale Price Asset/Portfolio ​ Metropolitan Statistical Area ​ Transaction Date ​ Stores ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 Acquisitions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Texas Asset ​ San Antonio, TX ​ February 2020 ​ 1 ​ $ 9,025 ​ Maryland Asset ​ Baltimore-Towson, MD ​ April 2020 ​ 1 ​ ​ 17,200 ​ New Jersey Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ April 2020 ​ 1 ​ ​ 48,450 ​ Florida Asset ​ Palm Bay-Melbourne-Titusville, FL ​ November 2020 ​ 1 ​ ​ 3,900 ​ Texas Asset ​ Austin-Round Rock, TX ​ November 2020 ​ 1 ​ ​ 10,750 ​ Texas Asset ​ Dallas-Fort Worth-Arlington, TX ​ November 2020 ​ 1 ​ ​ 10,150 ​ Nevada Asset ​ Las Vegas-Paradise, NV ​ December 2020 ​ 1 ​ ​ 16,800 ​ New York Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 1 ​ ​ 6,750 ​ Florida Asset ​ Tampa-St. Petersburg-Clearwater, FL ​ December 2020 ​ 1 ​ ​ 10,000 ​ Virginia Asset ​ Washington-Arlington-Alexandria, DC-VA-MD-WV ​ December 2020 ​ 1 ​ ​ 17,350 ​ Storage Deluxe Assets ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 8 ​ ​ 540,000 ​ Florida Assets ​ Orlando-Kissimmee, FL / Deltona-Daytona Beach-Ormond Beach, FL ​ December 2020 ​ 3 ​ ​ 45,500 ​ ​ ​ ​ ​ ​ ​ 21 ​ $ 735,875 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 Disposition: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ New York Asset ​ New York-Northern New Jersey-Long Island, NY-NJ-PA ​ December 2020 ​ 1 ​ $ 12,750 ​ ​ ​ ​ ​ ​ ​ 1 ​ $ 12,750 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

INVESTMENT ACTIVITY (Tables)

INVESTMENT ACTIVITY (Tables)	3 Months Ended
	Mar. 31, 2021
INVESTMENT ACTIVITY
Schedule of capitalized costs for investments in storage properties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CubeSmart ​ ​ ​ ​ ​ Number of ​ ​ ​ Ownership ​ Total Store Location Stores Date Opened ​ Interest ​ Construction Costs ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Arlington, VA (1) ​ 1 ​ Q1 2021 ​ 90% ​ $ 26,400 Brooklyn, NY (2) ​ 1 ​ Q2 2020 ​ 100% ​ ​ 45,900 ​ ​ 2 ​ ​ ​ ​ ​ $ 72,300 ​ (1) This store is located adjacent to an existing consolidated joint venture store. Given their proximity to each other, the stores have been combined in our store count, as well as for operational and reporting purposes (see note 13). ​ (2) This store was previously owned by a consolidated joint venture, in which the Company held a 51% ownership interest. On September 29, 2020, the noncontrolling member in the venture that owned the store put its 49% interest in the venture to the Company for $10.0 million, of which $1.0 million was paid in cash. T he Company issued 276,497 OP Units that were valued at approximately $9.0 million as consideration for the remainder of the purchase price (see note 13).

INVESTMENT IN UNCONSOLIDATED _2

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURE (Tables)	3 Months Ended
	Mar. 31, 2021
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES
Schedule of investments in real estate ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CubeSmart ​ Number of Stores as of ​ Carrying Value of Investment as of ​ ​ Ownership ​ March 31, ​ December 31, ​ March 31, ​ December 31, Unconsolidated Real Estate Ventures Interest ​ 2021 ​ 2020 2021 ​ 2020 191 V CUBE LLC ("HVP V") (1) ​ 20% ​ 1 ​ - ​ $ 2,819 ​ $ - 191 IV CUBE Southeast LLC ("HVPSE") (2) ​ 10% ​ 14 ​ 14 ​ ​ 4,829 ​ ​ 5,015 191 IV CUBE LLC ("HVP IV") (3) ​ 20% ​ 22 ​ 21 ​ ​ 25,348 ​ ​ 21,760 CUBE HHF Northeast Venture LLC ("HHFNE") (4) ​ 10% ​ 13 ​ 13 ​ ​ 1,524 ​ ​ 1,628 CUBE HHF Limited Partnership ("HHF") (5) ​ 50% ​ 35 ​ 35 ​ ​ 59,277 ​ ​ 63,668 ​ ​ ​ ​ 85 ​ 83 ​ $ 93,797 ​ $ 92,071 ​ (1) On March 17, 2021, the Company invested a 20% ownership interest in a newly-formed real estate venture that acquired its initial self-storage property located in Florida. HVP V paid $14.0 million for this store, of which $0.9 million was allocated to the value of the in-place lease intangible. The purchase price was contributed pro-rata by the Company and its unaffiliated joint venture partner. The Company’s total contribution to HVP V related to this acquisition was $2.8 million. ​ (2) On March 19, 2020, the Company invested a 10% ownership interest in a newly-formed real estate venture that acquired 14 self-storage properties located in Florida (2) , Georgia (8) and South Carolina (4) . HVPSE paid $135.3 million for these stores, of which $7.7 million was allocated to the value of the in-place lease intangible. The acquisition was funded primarily through the venture’s $81.6 million secured term loan. The remainder of the purchase price was contributed pro-rata by the Company and its unaffiliated joint venture partner. The Company’s total contribution to HVPSE related to this portfolio acquisition was $5.6 million. The secured loan bears interest at LIBOR plus 1.60% and matures on March 19, 2023 with options to extend the maturity date through March 19, 2025, subject to satisfaction of certain conditions and payment of the extension fees as stipulated in the loan agreement. ​ (3) The stores owned by HVP IV are located in Arizona (2) , Connecticut (2) , Florida (4) , Georgia (2) , Maryland (2) , Minnesota (1) , Pennsylvania (1) and Texas (8) . The Company’s total contribution to HVP IV in connection with these store acquisitions was $30.1 million. As of March 31, 2021, HVP IV had $82.2 million outstanding on its $107.0 million secured loan facility, which bears interest at LIBOR plus 1.70% per annum, and matures on May 16, 2021. As of March 31, 2021, HVP IV also had $55.5 million outstanding under a separate secured loan that bears interest at LIBOR plus 2.75% per annum, and matures on June 9, 2022 with options to extend the maturity date through June 9, 2024, subject to satisfaction of certain conditions and payment of the extension fees as stipulated in the loan agreement. On April 19, 2021, HVP IV entered into a new secured loan and received $121.3 million in proceeds from the initial advance of the loan, which it used to repay the $82.2 million outstanding on its $107.0 million secured loan facility. The new secured loan bears interest at 1.95% over LIBOR and matures on April 19, 2025. ​ (4) The stores owned by HHFNE are located in Connecticut (3) , Massachusetts (6) , Rhode Island (2) and Vermont (2) . The Company’s total contribution to HHFNE in connection with these store acquisitions was $3.8 million. As of March 31, 2021, HHFNE had an outstanding $45.0 million secured loan facility, which bears interest at LIBOR plus 1.20% per annum and matures on December 16, 2024. ​ (5) The stores owned by HHF are located in North Carolina (1) and Texas (34) . On January 21, 2021, HHF entered into a new $105.0 million secured loan, which bears interest at 2.58% per annum and matures on February 5, 2028. HHF used the proceeds from this loan to repay its existing outstanding $100.0 million loan in full.
Summary of the financial position of the ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 2020 (1) Assets ​ (in thousands) Storage properties, net ​ $ 686,849 ​ $ 662,833 Other assets ​ 22,924 ​ 18,112 Total assets ​ $ 709,773 ​ $ 680,945 ​ ​ ​ ​ ​ ​ ​ Liabilities and equity ​ ​ ​ ​ ​ ​ Debt ​ $ 367,547 ​ $ 359,985 Other liabilities ​ ​ 12,494 ​ ​ 11,588 Equity ​ ​ ​ ​ ​ ​ CubeSmart ​ 93,797 ​ ​ 92,071 Joint venture partners ​ 235,935 ​ ​ 217,301 Total liabilities and equity ​ $ 709,773 ​ $ 680,945 ​ ​ ​ ​ ​ ​ ​ (1) Excludes HVP V as it acquired its initial asset on March 17, 2021.
Summary of results of operations of the ventures	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2021 (1) 2020 (2) ​ ​ (in thousands) ​ Total revenues ​ $ 18,823 ​ $ 14,605 ​ ​ Operating expenses ​ (8,605) ​ ​ (6,942) ​ ​ Other income (expenses) ​ ​ 3 ​ ​ (113) ​ ​ Interest expense, net ​ (3,535) ​ ​ (2,720) ​ ​ Depreciation and amortization ​ (8,713) ​ (6,423) ​ ​ Net loss ​ $ (2,027) ​ $ (1,593) ​ ​ Company’s share of net income (loss) ​ $ 20 ​ $ (5) ​ ​ ​ ​ ​ ​ (1) Represents a partial quarter of HVP V as it acquired its initial asset on March 17, 2021. ​ (2) Excludes HVP V as it acquired its initial asset on March 17, 2021 and represents a partial quarter of HVPSE as it acquired its initial assets on March 19, 2020.

OTHER ASSETS (Tables)

OTHER ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
Other Assets, Unclassified [Abstract]
Schedule of other assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 ​ ​ (in thousands) Intangible assets, net of accumulated amortization of $16,688 and $2,123 ​ $ 42,867 ​ $ 57,820 Accounts receivable, net ​ 5,313 ​ 5,829 Prepaid property taxes ​ 5,403 ​ 6,334 Prepaid property and casualty insurance ​ 1,540 ​ 2,626 Amounts due from affiliates (see note 15) ​ ​ 15,048 ​ ​ 13,130 Assets held in trust related to deferred compensation arrangements ​ ​ 19,345 ​ ​ 17,207 Right-of-use assets - operating leases (see note 14) ​ ​ 54,989 ​ ​ 55,302 Equity investment recorded at cost (1) ​ ​ 5,000 ​ ​ 5,000 Other ​ 7,684 ​ 7,505 Total other assets, net ​ $ 157,189 ​ $ 170,753 ​ (1) On September 5, 2018, the Company invested $5.0 million in exchange for 100% of the Class A preferred units of Capital Storage Partners, LLC (“Capital Storage”), a newly formed venture that acquired 22 self-storage properties located in Florida (4) , Oklahoma (5) and Texas (13) . The Class A preferred units earn an 11% cumulative dividend prior to any other distributions. The Company’s investment in Capital Storage and the related dividends are included in Other assets, net on the Company’s consolidated balance sheets and in Other income on the Company’s consolidated statements of operations, respectively.

UNSECURED SENIOR NOTES (Tables)

UNSECURED SENIOR NOTES (Tables)	3 Months Ended
	Mar. 31, 2021
Senior Notes
Summary of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Effective ​ Issuance ​ Maturity Unsecured Senior Notes 2021 2020 Interest Rate ​ Date ​ Date ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ $300M 4.375% Guaranteed Notes due 2023 (1) ​ $ 300,000 ​ $ 300,000 4.33 % ​ Various (1) ​ Dec-23 ​ $300M 4.000% Guaranteed Notes due 2025 (2) ​ 300,000 ​ 300,000 3.99 % ​ Various (2) ​ Nov-25 ​ $300M 3.125% Guaranteed Notes due 2026 ​ ​ 300,000 ​ ​ 300,000 ​ 3.18 % ​ Aug-16 ​ Sep-26 ​ $350M 4.375% Guaranteed Notes due 2029 ​ ​ 350,000 ​ ​ 350,000 ​ 4.46 % ​ Jan-19 ​ Feb-29 ​ $350M 3.000% Guaranteed Notes due 2030 ​ ​ 350,000 ​ ​ 350,000 ​ 3.04 % ​ Oct-19 ​ Feb-30 ​ $450M 2.000% Guaranteed Notes due 2031 ​ ​ 450,000 ​ ​ 450,000 ​ 2.10 % ​ Oct-20 ​ Feb-31 ​ Principal balance outstanding ​ ​ 2,050,000 ​ ​ 2,050,000 ​ ​ ​ ​ ​ ​ ​ ​ Less: Discount on issuance of unsecured senior notes, net ​ ​ (7,278) ​ ​ (7,470) ​ ​ ​ ​ ​ ​ ​ ​ Less: Loan procurement costs, net ​ ​ (11,723) ​ ​ (12,158) ​ ​ ​ ​ ​ ​ ​ ​ Total unsecured senior notes, net ​ $ 2,030,999 ​ $ 2,030,372 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) On April 4, 2017, the Operating Partnership issued $50.0 million of its 4.375% senior notes due 2023, which are part of the same series as the $250.0 million principal amount of the Operating Partnership’s 4.375% senior notes due December 15, 2023 issued on December 17, 2013. The $50.0 million and $250.0 million tranches were priced at 105.040% and 98.995% , respectively, of the principal amount to yield 3.495% and 4.501% , respectively, to maturity. The combined weighted average effective interest rate of the 2023 notes is 4.330% . ​ (2) On April 4, 2017, the Operating Partnership issued $50.0 million of its 4.000% senior notes due 2025, which are part of the same series as the $250.0 million principal amount of the Operating Partnership’s 4.000% senior notes due November 15, 2025 issued on October 26, 2015. The $50.0 million and $250.0 million tranches were priced at 101.343% and 99.735% , respectively, of the principal amount to yield 3.811% and 4.032% , respectively, to maturity. The combined weighted average effective interest rate of the 2025 notes is 3.994% . ​

MORTGAGE LOANS AND NOTES PAYA_2

MORTGAGE LOANS AND NOTES PAYABLE (Tables) - Mortgages	3 Months Ended
	Mar. 31, 2021
Summary of debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Value as of ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Effective ​ Maturity Mortgage Loans and Notes Payable 2021 2020 Interest Rate ​ Date ​ ​ (in thousands) ​ ​ ​ ​ ​ Bronx IX, NY (1) ​ $ — ​ $ 21,030 4.85 % ​ Jun-21 ​ Bronx X, NY (1) ​ — ​ 23,148 4.64 % ​ Jun-21 ​ Nashville V, TN ​ ​ 2,247 ​ ​ 2,261 ​ 3.85 % ​ Jun-23 ​ New York, NY ​ ​ 29,819 ​ ​ 29,981 ​ 3.51 % ​ Jun-23 ​ Annapolis I, MD ​ ​ 5,238 ​ ​ 5,283 ​ 3.78 % ​ May-24 ​ Brooklyn XV, NY ​ ​ 15,658 ​ ​ 15,713 ​ 2.15 % ​ May-24 ​ Long Island City IV, NY ​ ​ 12,801 ​ ​ 12,852 ​ 2.15 % ​ May-24 ​ Long Island City II, NY ​ ​ 19,034 ​ ​ 19,094 ​ 2.25 % ​ Jul-26 ​ Long Island City III, NY ​ ​ 19,022 ​ ​ 19,106 ​ 2.25 % ​ Aug-26 ​ Flushing II, NY ​ ​ 54,300 ​ ​ 54,300 ​ 2.15 % ​ Jul-29 ​ Principal balance outstanding ​ ​ 158,119 ​ ​ 202,768 ​ ​ ​ ​ ​ ​ Plus: Unamortized fair value adjustment ​ ​ 15,080 ​ 15,879 ​ ​ ​ ​ ​ ​ Less: Loan procurement costs, net ​ ​ (2,010) ​ ​ (2,143) ​ ​ ​ ​ ​ ​ Total mortgage loans and notes payable, net ​ $ 171,189 ​ $ 216,504 ​ ​ ​ ​ ​ ​ ​ (1) These mortgage loans were repaid in full on March 1, 2021. ​
Schedule of the future principal payment requirements on the outstanding mortgage loans and notes payable	The following table represents the future principal payment requirements on the outstanding mortgage loans and notes payable as of March 31, 2021 (in thousands): ​ ​ ​ ​ ​ 2021 $ 1,733 2022 ​ 2,426 2023 ​ 32,591 2024 ​ 32,329 2025 ​ 979 2026 and thereafter ​ 88,061 Total mortgage payments ​ 158,119 Plus: Unamortized fair value adjustment ​ 15,080 Less: Loan procurement costs, net ​ ​ (2,010) Total mortgage loans and notes payable, net ​ $ 171,189

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	3 Months Ended
	Mar. 31, 2021
ACCUMULATED OTHER COMPREHENSIVE LOSS
Summary of changes in accumulated other comprehensive loss by component	The following table summarizes the changes in accumulated other comprehensive loss by component for the three months ended March 31, 2021 (in thousands): ​ ​ ​ ​ ​ March 31, ​ 2021 ​ ​ (in thousands) Beginning balance $ (656) Reclassification of realized losses on interest rate swaps (1) ​ 20 Ending balance ​ (636) Less: portion included in noncontrolling interests in the Operating Partnership ​ 23 Total accumulated other comprehensive loss included in equity $ (613) ​ (1) See note 11 for additional information about the effects of the amounts reclassified.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
FAIR VALUE MEASUREMENTS
Schedule of financial assets and liabilities carried at fair value	​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 ​ 2020 ​ ​ (in thousands) Carrying value $ 2,254,988 ​ $ 2,364,676 Fair value ​ 2,348,913 ​ ​ 2,571,300

NONCONTROLLING INTERESTS (Table

NONCONTROLLING INTERESTS (Tables)	3 Months Ended
	Mar. 31, 2021
NONCONTROLLING INTERESTS
Schedule of noncontrolling interests in subsidiaries	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Date Opened / ​ CubeSmart ​ ​ ​ ​ ​ ​ ​ ​ ​ Number ​ ​ ​ Estimated ​ Ownership ​ March 31, 2021 ​ Consolidated Joint Ventures of Stores Location Opening ​ Interest ​ Total Assets ​ Total Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ CS Vienna, LLC ("Vienna") (1) ​ 1 ​ Vienna, VA ​ Q2 2022 (est.) ​ 72% ​ $ 17,865 ​ $ 6,553 ​ CS 750 W Merrick Rd, LLC ("Merrick") (2) ​ 1 ​ Valley Stream, NY ​ Q1 2022 (est.) ​ 51% ​ ​ 15,626 ​ ​ 8,181 ​ CS Valley Forge Village Storage, LLC ("VFV") (3) ​ 1 ​ King of Prussia, PA ​ Q2 2021 (est.) ​ 70% ​ ​ 20,654 ​ ​ 12,333 ​ CS 2087 Hempstead Tpk, LLC ("Hempstead") (2) ​ 1 ​ East Meadow, NY ​ Q2 2021 (est.) ​ 51% ​ ​ 24,336 ​ ​ 7,104 ​ CS SDP Newtonville, LLC ("Newton") (3) ​ 1 ​ Newton, MA ​ Q2 2021 (est.) ​ 90% ​ ​ 18,345 ​ ​ 11,828 ​ SH3, LLC ("SH3") (4) ​ 1 ​ Arlington, VA Q2 2015/Q1 2021 ​ 90% ​ ​ 39,659 ​ ​ 6,667 ​ ​ ​ 6 ​ ​ ​ ​ ​ ​ ​ $ 136,485 ​ $ 52,666 ​ ​ (1) On December 23, 2020, the Company and the noncontrolling member contributed a previously wholly-owned operating property (the “Vienna Operating Property”) and a parcel of land (the “Vienna Land”), respectively, to Vienna. The Vienna Operating Property and the Vienna Land are located in close proximity to each other in Vienna, VA. The members intend to construct a new store on the Vienna Land, which, upon completion, will be combined with the Vienna Operating Property and operated by the venture as a single store. The Company has a related party commitment to Vienna to fund all or a portion of the construction costs. As of March 31, 2021, the Company has funded $ 5.4 million of a total $17.0 million loan commitment to Vienna, which is included in the total liabilities amount within the table above. This loan and the related interest were eliminated for consolidation purposes. ​ (2) The noncontrolling members of Merrick and Hempstead have the option to put their ownership interest in the ventures to the Company for $17.1 million and $6.6 million (the “Put Option”), respectively, within the two-year period after construction of each store is substantially complete (the “Put Option Period”). In the event the Put Option is not exercised, the Company has a one-year option to call the ownership interest of the noncontrolling members of Merrick and Hempstead for $17.1 million and $6.6 million, respectively, beginning twelve months after the end of the Put Option Period. The Company, at its sole discretion, may pay cash and/or issue OP Units, in exchange for the noncontrolling member’s interest in Merrick and Hempstead. The Company is accreting the respective liabilities during the development periods and, as of March 31, 2021, has accrued $7.3 million and $6.2 million, related to Merrick and Hempstead, respectively, which are included in Accounts payable, accrued expenses and other liabilities on the Company’s consolidated balance sheets. ​ (3) The Company has related party loan commitments to VFV and Newton to fund a portion of the construction costs. As of March 31, 2021, the Company has funded $9.6 million of the total $12.4 million loan commitment to VFV and $11.1 million of the total $12.1 million loan commitment to Newton, which are included in the total liability amounts within the table above. These loans and the related interest were eliminated for consolidation purposes. ​ (4) SH3 owns two stores located in close proximity to each other in Arlington, VA, the first of which was developed and opened for operation in April 2015 (“Shirlington I”) and the second of which was developed and opened for operation in March 2021 (“Shirlington II”). Given their close proximity to each other, the two stores were combined in our store count, as well as for operational and reporting purposes, upon the opening of Shirlington II in March 2021.

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2021
LEASES
Summary of lease cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ ​ 2021 2020 ​ ​ ​ ​ (in thousands) Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ Amortization of finance lease right-of-use assets ​ $ 241 ​ $ — ​ ​ Interest expense related to finance lease liabilities ​ ​ 526 ​ ​ — ​ ​ Operating lease cost ​ ​ 822 ​ ​ 746 ​ ​ Short-term lease cost (1) ​ 306 ​ ​ 308 ​ ​ Total lease cost ​ $ 1,895 ​ $ 1,054 ​ ​ ​ (1) Represents automobile leases that have a lease term of 12 months . The Company has made an accounting policy election not to apply the recognition requirements of ASC 842 to this asset class. The lease cost associated with these leases is recognized on a straight-line basis over the related lease term.
Schedule of balance sheet information associated with operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ ​ (dollars in thousands) ​ Finance Leases ​ ​ ​ ​ ​ ​ ​ Right-of-use assets included in Storage properties, net ​ $ 41,655 ​ $ 41,896 ​ Lease liabilities included in Lease liabilities - finance leases ​ $ 65,710 ​ $ 65,599 ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases ​ ​ ​ ​ ​ ​ ​ Right-of-use assets included in Other assets, net ​ $ 54,989 ​ $ 55,302 ​ Lease liabilities included in Accounts payable, accrued expenses and other liabilities ​ $ 53,541 ​ $ 53,595 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Lease Term (in years) ​ ​ ​ ​ ​ ​ ​ Finance leases ​ ​ 43.3 ​ ​ 43.5 ​ Operating leases ​ ​ 34.6 ​ ​ 34.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average Discount Rate ​ ​ ​ ​ ​ ​ ​ Finance leases ​ ​ 3.25 % ​ 3.25 % Operating leases ​ ​ 4.47 % ​ 4.46 %
Schedule of future operating lease liability maturities	The following table represents the future lease liability maturities as of March 31, 2021 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating 2021 $ 1,520 $ 1,893 2022 ​ 2,183 ​ 2,639 2023 ​ 2,183 ​ 2,690 2024 ​ 2,183 ​ 2,540 2025 ​ 2,224 ​ 2,539 2026 and thereafter ​ 122,932 ​ 99,290 Total lease payments ​ 133,225 ​ 111,591 Less: Imputed interest ​ ​ (67,515) ​ ​ (58,050) Present value of lease liabilities ​ $ 65,710 ​ $ 53,541 ​ ​ ​ ​ ​ ​ ​

ORGANIZATION AND NATURE OF OP_2

ORGANIZATION AND NATURE OF OPERATIONS (Details)	3 Months Ended
	Mar. 31, 2021statesegment
Number of states in which self-storage facilities are located | state	24
Number of reportable segments | segment	1
Common stock, conversion ratio	1
Cubesmart
Percentage of the entity's partnership interest in Operating Partnership	96.50%

STORAGE PROPERTIES - Summary (D

STORAGE PROPERTIES - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
STORAGE FACILITIES
Storage properties	$ 5,492,183	$ 5,489,754
Less: Accumulated depreciation	(997,712)	(983,940)
Storage properties, net (including VIE assets of $136,141 and $119,345, respectively)	4,494,471	4,505,814
Land
STORAGE FACILITIES
Storage properties	1,100,598	1,093,503
Buildings and improvements
STORAGE FACILITIES
Storage properties	4,130,146	4,122,995
Equipment
STORAGE FACILITIES
Storage properties	120,871	123,044
Construction in progress
STORAGE FACILITIES
Storage properties	98,913	108,316
Right-of-use assets - finance leases
STORAGE FACILITIES
Storage properties	$ 41,655	$ 41,896

STORAGE PROPERTIES - Activity (

STORAGE PROPERTIES - Activity (Details) $ in Thousands	3 Months Ended	12 Months Ended	15 Months Ended
	Mar. 31, 2021facility	Dec. 31, 2020USD ($)property	Mar. 31, 2021USD ($)facility
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility	0
Number of Facilities, dispositions (in properties) | facility			1
Sale Price | $			$ 12,750
2020 Acquisitions
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties)		13	21
Purchase Price | $		$ 195,900	$ 735,875
2020 Acquisitions | Texas Asset February 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 9,025
2020 Acquisitions | Maryland Asset April 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 17,200
2020 Acquisitions | New Jersey Asset April 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 48,450
2020 Acquisitions | Florida Asset November 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 3,900
2020 Acquisitions | Texas Asset, Austin, November 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 10,750
2020 Acquisitions | Texas Asset, Dallas, November 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 10,150
2020 Acquisitions | Nevada Asset December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 16,800
2020 Acquisitions | New York Asset December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 6,750
2020 Acquisitions | Storage Deluxe Assets December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			8
Purchase Price | $			$ 540,000
2020 Acquisitions | Florida Asset, Orlando, December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			3
Purchase Price | $			$ 45,500
2020 Acquisitions | Florida Assets, Tampa, December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 10,000
2020 Acquisitions | Virginia Asset December 2020
STORAGE FACILITIES
Number of Facilities, acquisitions (in properties) | facility			1
Purchase Price | $			$ 17,350
2020 Dispositions | New York Asset December 2020
STORAGE FACILITIES
Number of Facilities, dispositions (in properties) | facility			1
Sale Price | $			$ 12,750

INVESTMENT ACTIVITY (Details)

INVESTMENT ACTIVITY (Details)	Dec. 22, 2020USD ($)	Sep. 29, 2020USD ($)shares	Jul. 20, 2020USD ($)	Mar. 31, 2021USD ($)propertyfacility	Mar. 31, 2020USD ($)	Dec. 31, 2018	Dec. 31, 2020USD ($)propertyitemfacility	Mar. 31, 2021USD ($)propertyfacility
Self-storage facilities
Number of self-storage facilities acquired | facility				0
Number of self-storage facilities sold | facility				0
Aggregate sale price								$ 12,750,000
Number of facilities, construction completed and opened								2
Construction
Self-storage facilities
Total Construction Costs								$ 72,300,000
New York
Self-storage facilities
Aggregate purchase price			$ 9,500,000
Decrease in right-of-use asset			(5,100,000)
Decrease in operating lease liability			$ (5,000,000)
Cash paid for acquisition		$ 1,000,000
Total consideration		$ 10,000,000
Units issued (in shares) | shares		276,497
Units issued		$ 9,000,000
Self storage under construction
Self-storage facilities
Number of facilities under contract | property				5				5
Self storage under construction | New York
Self-storage facilities
Number of facilities under contract | facility				2				2
Self storage under construction | Massachusetts
Self-storage facilities
Number of facilities under contract | facility				1				1
Self storage under construction | Virginia
Self-storage facilities
Number of facilities under contract | property				1				1
Self storage under construction | Pennsylvania
Self-storage facilities
Number of facilities under contract | facility				1				1
Self-storage Facility in Brooklyn, NY
Self-storage facilities
Number of facilities, construction completed and opened								$ 1
Ownership interest held by the entity (as a percent)								100.00%
Self-storage Facility in Brooklyn, NY | Construction
Self-storage facilities
Total Construction Costs								$ 45,900,000
Self-storage Facility in Arlington, VA
Self-storage facilities
Number of facilities, construction completed and opened								$ 1
Ownership interest held by the entity (as a percent)								90.00%
Self-storage Facility in Arlington, VA | Construction
Self-storage facilities
Total Construction Costs								$ 26,400,000
2020 Acquisitions
Self-storage facilities
Number of self-storage facilities acquired							13	21
Aggregate purchase price							$ 195,900,000	$ 735,875,000
2020 Acquisitions | Leases, Acquired-in-Place
Self-storage facilities
Intangible value of the in-place leases							$ 11,400,000
Estimated life							12 months
Amortization expense				$ 2,800,000	$ 32,000
2020 Acquisitions | Texas
Self-storage facilities
Number of self-storage facilities acquired | property							3
2020 Acquisitions | Florida
Self-storage facilities
Number of self-storage facilities acquired | property							5
2020 Acquisitions | New York
Self-storage facilities
Number of self-storage facilities acquired | property							1
2020 Acquisitions | Maryland
Self-storage facilities
Number of self-storage facilities acquired | property							1
2020 Acquisitions | Nevada
Self-storage facilities
Number of self-storage facilities acquired | property							1
2020 Acquisitions | Virginia
Self-storage facilities
Number of self-storage facilities acquired | property							1
2020 Acquisitions | New Jersey
Self-storage facilities
Number of self-storage facilities acquired | property				1			1
2020 Acquisitions | Self-storage facilities located in New York
Self-storage facilities
Number of self-storage facilities acquired | facility							8
Number of real estate property acquisition tranches | item							2
Aggregate purchase price							$ 540,000,000
Intangible value of the in-place leases							48,600,000
Cash paid for acquisition							210,500,000
Issuance of OP Shares							175,100,000
Repayments of debt							33,200,000
Units issued							$ 5,272,023
Number of properties, assumed mortgage | item							6
Assumed mortgage debt, at fair value							$ 169,200,000
Outstanding principal balance of mortgage debt assumed on acquisitions							154,400,000
Premium on debt assumed on acquisitions							$ 14,800,000
2020 Acquisitions | Self-storage facilities located in New York | Leases, Acquired-in-Place
Self-storage facilities
Estimated life							12 months
Amortization expense				$ 12,100,000
Number of assumed ground leases | item							3
Number of facilities acquired with existing ground leases, for which the leases were classifed as finance leases | item							2
Number of facilities acquired with existing ground leases, for which the leases were classified as operating leases | item							1
2020 Dispositions | Self-storage facilities located in New York
Self-storage facilities
Aggregate sale price	$ 12,800,000
Gains from sale of real estate, net	$ 6,700,000
Real Estate Acquisitions Expected in 2019 | Self storage under construction
Self-storage facilities
Development costs				85,700,000				85,700,000
Expected construction cost				$ 124,300,000				$ 124,300,000
Joint Venture | Self Storage Facility in Bayonne, NJ
Self-storage facilities
Ownership interest held by the entity (as a percent)						51.00%
Joint Venture | Self Storage Facility in Brooklyn, NY I
Self-storage facilities
Put option ownership percentage in joint venture exercised (as a percent)		49.00%
Option to put ownership interest in the venture		$ 10,000,000
Cash portion of put option paid		$ 1,000,000
Units issued (in shares) | shares		276,497
Units issued		$ 9,000,000

INVESTMENT IN UNCONSOLIDATED _3

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURE (Details) $ in Thousands	Apr. 19, 2021USD ($)	Mar. 17, 2021USD ($)	Feb. 05, 2021USD ($)	Mar. 19, 2020USD ($)facility	Sep. 05, 2018USD ($)property	Dec. 15, 2016	Mar. 31, 2021USD ($)propertyfacility	Mar. 31, 2020USD ($)	Mar. 31, 2021USD ($)property	Jan. 21, 2021USD ($)	Dec. 31, 2020USD ($)property
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 93,797		$ 93,797		$ 92,071
Number of self-storage facilities acquired | facility							0
Acquisitions of storage facilities								$ 9,090
Number of assets sold | facility							0
Aggregate sale price									12,750
Credit facility, outstanding							$ 52,800		52,800		117,800
Investment in joint venture							5,000		5,000		5,000
Summary of results of operations of the real estate venture
Company's share of net (loss) income							20	(5)
HVPSE
Investment in Unconsolidated Real Estate Venture
Ownership interest in partnership (as a percent)				10.00%
Number of self-storage facilities acquired | facility				14
Acquisitions of storage facilities				$ 135,300
Intangible value of the in-place leases				7,700
Contribution To Real Estate Venture				$ 5,600
Interest rate (as percentage)				1.60%
HVPSE | Term Loan Facility
Investment in Unconsolidated Real Estate Venture
Proceeds from debt				$ 81,600
HVP IV | Secured Loan Due May 2021
Investment in Unconsolidated Real Estate Venture
Credit facility, outstanding							82,200		82,200
Maximum borrowing capacity	$ 107,000						107,000		107,000
Amount of debt repaid	82,200
HVP IV | Secured Debt Due April 2025
Investment in Unconsolidated Real Estate Venture
Proceeds from debt	$ 121,300
HVP IV | Secured Debt Due June 2024
Investment in Unconsolidated Real Estate Venture
Outstanding debt							$ 55,500		55,500
HVP IV | LIBOR | Secured Loan Due May 2021
Investment in Unconsolidated Real Estate Venture
Interest rate (as percentage)							1.70%
HVP IV | LIBOR | Secured Debt Due April 2025
Investment in Unconsolidated Real Estate Venture
Interest rate (as percentage)	1.95%
HVP IV | LIBOR | Secured Debt Due June 2024
Investment in Unconsolidated Real Estate Venture
Interest rate (as percentage)							2.75%
HHFNE
Investment in Unconsolidated Real Estate Venture
Outstanding debt							$ 45,000		$ 45,000
HHFNE | LIBOR
Investment in Unconsolidated Real Estate Venture
Interest rate (as percentage)						1.20%
HHFNE | LIBOR | Secured Debt Due December 2019
Investment in Unconsolidated Real Estate Venture
Interest rate (as percentage)							1.20%
Arizona | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Maryland | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Connecticut | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Connecticut | HHFNE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							3		3
Massachusetts | HHFNE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							6		6
Minnesota | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							1		1
Rhode Island | HHFNE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Vermont | HHFNE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Florida | HVPSE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | facility				(2)
Florida | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							4		4
Texas | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							8		8
Texas | HHF
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							34		34
North Carolina | HHF
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							1		1
South Carolina | HVPSE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | facility				(4)
Georgia | HVPSE
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | facility				(8)
Georgia | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							2		2
Pennsylvania | HVP IV
Investment in Unconsolidated Real Estate Venture
Number of storage facilities owned by investee | property							1		1
Ventures
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 93,797		$ 93,797		$ 92,071
Number of storage facilities owned by investee | property							85		85		83
Assets
Storage propeties, net							$ 686,849		$ 686,849		$ 662,833
Other assets							22,924		22,924		18,112
Total Assets							709,773		709,773		680,945
Liabilities and equity
Other liabilities							12,494		12,494		11,588
Debt							367,547		367,547		359,985
Equity
CubeSmart							93,797		93,797		92,071
Joint venture partner							235,935		235,935		217,301
Total liabilities and equity							709,773		709,773		680,945
Summary of results of operations of the real estate venture
Total revenues							18,823	14,605
Operating expenses							(8,605)	(6,942)
Other expenses							3	(113)
Interest expense, net							(3,535)	(2,720)
Depreciation and amortization							(8,713)	(6,423)
Net (loss) income							(2,027)	(1,593)
Company's share of net (loss) income							20	$ (5)
HVP V
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 2,819		$ 2,819
Ownership interest in partnership (as a percent)		20.00%					20.00%		20.00%
Number of storage facilities owned by investee | property							1		1
Acquisitions of storage facilities		$ 14,000
Intangible value of the in-place leases		900
Contribution To Real Estate Venture		$ 2,800
HVPSE
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 4,829		$ 4,829		$ 5,015
Ownership interest in partnership (as a percent)							10.00%		10.00%
Number of storage facilities owned by investee | property							14		14		14
HVP IV
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 25,348		$ 25,348		$ 21,760
Ownership interest in partnership (as a percent)							20.00%		20.00%
Number of storage facilities owned by investee | property							22		22		21
Contribution To Real Estate Venture							$ 30,100		$ 30,100
HHFNE
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 1,524		$ 1,524		$ 1,628
Ownership interest in partnership (as a percent)							10.00%		10.00%
Number of storage facilities owned by investee | property							13		13		13
Contribution To Real Estate Venture							$ 3,800		$ 3,800
HHF
Investment in Unconsolidated Real Estate Venture
Investment in real estate entities							$ 59,277		$ 59,277		$ 63,668
Ownership interest in partnership (as a percent)							50.00%		50.00%
Number of storage facilities owned by investee | property							35		35		35
Amount of loan obtained										$ 105,000
Interest on real estate venture debt										2.58%
Amount of debt repaid			$ 100,000
Capital Storage Partners, LLC
Investment in Unconsolidated Real Estate Venture
Ownership interest in partnership (as a percent)					100.00%
Number of self-storage facilities acquired | property					22
Investment in joint venture					$ 5,000
Series A Preferred shares, percentage					11.00%
Capital Storage Partners, LLC | Florida
Investment in Unconsolidated Real Estate Venture
Number of self-storage facilities acquired | property					4
Capital Storage Partners, LLC | Texas
Investment in Unconsolidated Real Estate Venture
Number of self-storage facilities acquired | property					13
Capital Storage Partners, LLC | Oklahoma
Investment in Unconsolidated Real Estate Venture
Number of self-storage facilities acquired | property					5

OTHER ASSETS (Details)

OTHER ASSETS (Details) $ in Thousands	Sep. 05, 2018USD ($)property	Mar. 31, 2021USD ($)facility	Dec. 31, 2020USD ($)
Other Assets
Intangible assets, net of accumulated amortization of $16,688 and $2,123		$ 42,867	$ 57,820
Accounts receivable, net		5,313	5,829
Prepaid property taxes		5,403	6,334
Prepaid property and casualty insurance		1,540	2,626
Amounts due from affiliates (see note 15)		15,048	13,130
Assets held in trust related to deferred compensation arrangements		19,345	17,207
Right-of-use assets (see note 14)		54,989	55,302
Equity investment recorded at cost		5,000	5,000
Other		7,684	7,505
Total		157,189	170,753
Accumulated amortization		$ 16,688	$ 2,123
Number of self-storage facilities acquired | facility		0
Capital Storage Partners, LLC
Other Assets
Equity investment recorded at cost	$ 5,000
Ownership interest in partnership (as a percent)	100.00%
Number of self-storage facilities acquired | property	22
Series A Preferred shares, percentage	11.00%
Capital Storage Partners, LLC | Florida
Other Assets
Number of self-storage facilities acquired | property	4
Capital Storage Partners, LLC | Oklahoma
Other Assets
Number of self-storage facilities acquired | property	5
Capital Storage Partners, LLC | Texas
Other Assets
Number of self-storage facilities acquired | property	13

UNSECURED SENIOR NOTES (Details

UNSECURED SENIOR NOTES (Details) $ in Thousands	Apr. 04, 2017USD ($)	Oct. 26, 2015USD ($)	Dec. 17, 2013USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Mortgage loans and Notes payable
Less: Loan procurement costs, net				$ (3,029)	$ (3,275)
Total unsecured senior notes, net				2,030,999	2,030,372
Cubesmart, L P and Subsidiaries
Mortgage loans and Notes payable
Less: Loan procurement costs, net				(3,029)	(3,275)
Total unsecured senior notes, net				2,030,999	2,030,372
Senior Notes
Mortgage loans and Notes payable
Senior notes, principal amount				2,050,000	2,050,000
Less: Discount on issuance of notes, net				(7,278)	(7,470)
Less: Loan procurement costs, net				(11,723)	(12,158)
Total unsecured senior notes, net				$ 2,030,999	2,030,372
Senior Notes | Maximum
Mortgage loans and Notes payable
Consolidated leverage ratio				0.60
Secured debt leverage ratio				0.40
Senior Notes | Minimum
Mortgage loans and Notes payable
Consolidated interest coverage ratio				1.50
Financial and customary covenant, minimum unencumbered asset (as a percent)				150.00%
Senior notes 4.375% due 2023
Mortgage loans and Notes payable
Senior notes, principal amount	$ 50,000		$ 250,000	$ 300,000	300,000
Interest rate (as a percent)	4.375%		4.375%	4.375%
Effective interest rate (as a percent)	3.495%		4.501%	4.33%
Effective weighted average interest rate (as a percent)				4.33%
Proceeds from senior notes	$ 50,000		$ 250,000
Debt instrument, redemption percentage	105.04%		98.995%
Senior notes 4.000% due 2025
Mortgage loans and Notes payable
Senior notes, principal amount	$ 50,000	$ 250,000		$ 300,000	300,000
Interest rate (as a percent)	4.00%	4.00%		4.00%
Effective interest rate (as a percent)	3.811%	4.032%		3.99%
Effective weighted average interest rate (as a percent)				3.994%
Proceeds from senior notes	$ 50,000	$ 250,000
Debt instrument, redemption percentage	101.343%	99.735%
Senior Notes 3.125% Due 2026
Mortgage loans and Notes payable
Senior notes, principal amount				$ 300,000	300,000
Interest rate (as a percent)				3.125%
Effective interest rate (as a percent)				3.18%
Senior Notes 4.375 % Due 2029
Mortgage loans and Notes payable
Senior notes, principal amount				$ 350,000	350,000
Interest rate (as a percent)				4.375%
Effective interest rate (as a percent)				4.46%
Senior Notes 3.000 % Due 2030
Mortgage loans and Notes payable
Senior notes, principal amount				$ 350,000	350,000
Interest rate (as a percent)				3.00%
Effective interest rate (as a percent)				3.04%
Senior Notes 2.000 % Due 2031
Mortgage loans and Notes payable
Senior notes, principal amount				$ 450,000	$ 450,000
Interest rate (as a percent)				2.00%
Effective interest rate (as a percent)				2.10%

REVOLVING CREDIT FACILITY (Deta

REVOLVING CREDIT FACILITY (Details) - USD ($) $ in Thousands	Apr. 04, 2017	Oct. 26, 2015	Dec. 17, 2013	Mar. 31, 2021	Dec. 31, 2020	Jun. 19, 2019
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Loan procurement costs, net of amortization				$ 3,029	$ 3,275
Less: Loan procurement costs, net				$ (3,029)	(3,275)
Revolver
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Effective interest rate (as a percent)				1.21%
Remaining borrowing capacity				$ 696,600
Outstanding letter of credit				$ 600
Credit Facility | Minimum
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Fixed charge coverage ratio				1.5
Credit Facility | Maximum
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Total indebtedness to total asset value ratio (as a percent)				60.00%
Credit Facility | Revolver
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Maximum borrowing capacity						$ 750,000
Interest rate, basis spread (as a percent)				1.10%
Facility fee (as a percent)				0.15%
Senior notes 4.375% due 2023
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Debt amount	$ 50,000		$ 250,000	$ 300,000	300,000
Proceeds from senior notes	$ 50,000		$ 250,000
Interest rate (as a percent)	4.375%		4.375%	4.375%
Effective interest rate (as a percent)	3.495%		4.501%	4.33%
Effective weighted average interest rate (as a percent)				4.33%
Senior notes 4.000% due 2025
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Debt amount	$ 50,000	$ 250,000		$ 300,000	300,000
Proceeds from senior notes	$ 50,000	$ 250,000
Interest rate (as a percent)	4.00%	4.00%		4.00%
Effective interest rate (as a percent)	3.811%	4.032%		3.99%
Effective weighted average interest rate (as a percent)				3.994%
Senior Notes 4.375 % Due 2029
SECURED CREDIT FACILITY, UNSECURED CREDIT FACILITY AND SECURED TERM LOANS
Debt amount				$ 350,000	$ 350,000
Interest rate (as a percent)				4.375%
Effective interest rate (as a percent)				4.46%

MORTGAGE LOANS AND NOTES PAYA_3

MORTGAGE LOANS AND NOTES PAYABLE - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Mortgage loans and Notes payable
Less: Loan procurement costs, net	$ (3,029)	$ (3,275)
Total mortgage loans and notes payable	171,189	216,504
Net book value of self-storage facilities	4,494,471	4,505,814
Mortgages
Mortgage loans and Notes payable
Carrying value	158,119	202,768
Plus: Unamortized fair value adjustment	15,080	15,879
Less: Loan procurement costs, net	(2,010)	(2,143)
Total mortgage loans and notes payable	171,189	216,504
Net book value of self-storage facilities	$ 457,000	539,200
Bronx IX, NY | Mortgages
Mortgage loans and Notes payable
Carrying value		21,030
Effective interest rate (as a percent)	4.85%
Bronx X, NY | Mortgages
Mortgage loans and Notes payable
Carrying value		23,148
Effective interest rate (as a percent)	4.64%
Nashville V, TN | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 2,247	2,261
Effective interest rate (as a percent)	3.85%
New York, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 29,819	29,981
Effective interest rate (as a percent)	3.51%
Annapolis I, MD | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 5,238	5,283
Effective interest rate (as a percent)	3.78%
Brooklyn XV, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 15,658	15,713
Effective interest rate (as a percent)	2.15%
Long Island City IV, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 12,801	12,852
Effective interest rate (as a percent)	2.15%
Long Island City II, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 19,034	19,094
Effective interest rate (as a percent)	2.25%
Long Island City III, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 19,022	19,106
Effective interest rate (as a percent)	2.25%
Flushing II, NY | Mortgages
Mortgage loans and Notes payable
Carrying value	$ 54,300	$ 54,300
Effective interest rate (as a percent)	2.15%

MORTGAGE LOANS AND NOTES PAYA_4

MORTGAGE LOANS AND NOTES PAYABLE - Future Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Future principal payment requirements on the outstanding mortgage loans and notes payable at year end
Less: Loan procurement costs, net	$ (3,029)	$ (3,275)
Total mortgage loans and notes payable, net	171,189	216,504
Mortgages
Future principal payment requirements on the outstanding mortgage loans and notes payable at year end
2021	1,733
2022	2,426
2023	32,591
2024	32,329
2025	979
2026 and thereafter	88,061
Total mortgage payments	158,119	202,768
Plus: Unamortized fair value adjustment	15,080	15,879
Less: Loan procurement costs, net	(2,010)	(2,143)
Total mortgage loans and notes payable, net	$ 171,189	$ 216,504

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Changes in accumulated other comprehensive income by component
Balance	$ 1,840,848	$ 1,807,336
Reclassification of realized losses on interest rate swaps	20	20
Balance	1,886,199	1,790,290
Unrealized losses on interest rate swaps
Changes in accumulated other comprehensive income by component
Unrealized losses on interest rate swaps	20
AOCI Including Portion Attributable to Noncontrolling Interest
Changes in accumulated other comprehensive income by component
Balance	(656)
Balance	(636)
Accumulated Other Comprehensive (Loss) Income
Changes in accumulated other comprehensive income by component
Balance	(632)	(729)
Balance	(613)	$ (709)
AOCI Attributable to Noncontrolling Interest
Changes in accumulated other comprehensive income by component
Balance	$ 23

RISK MANAGEMENT AND USE OF FI_2

RISK MANAGEMENT AND USE OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Jan. 24, 2019	Mar. 31, 2021	Dec. 24, 2018
Derivative financial instruments
Realized losses reclassified from accumulated other comprehensive loss		$ 20
Amount estimated to be reclassified as an increase to interest expense		$ 100
Interest rate swap
Derivative financial instruments
Notional Amount			$ 150,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Termination Premium	$ 800
Designated | Cash flow
Derivative financial instruments
Settlement of hedge transactions	$ 800

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair value of financial assets and liabilities carried at fair value
Derivative Assets	$ 0	$ 0
Derivative Liabilities	0	0
Level 2
Fair value of financial assets and liabilities carried at fair value
Aggregate carrying value of total debt	2,254,988	2,364,676
Estimated fair value of total debt	$ 2,348,913	$ 2,571,300

NONCONTROLLING INTERESTS - Inte

NONCONTROLLING INTERESTS - Interests in Consolidated Real Estate Joint Ventures (Details) $ in Thousands	3 Months Ended	15 Months Ended
	Mar. 31, 2021USD ($)facility	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Interests in Consolidated Real Estate Joint Ventures
Assets	$ 4,754,478	$ 4,754,478	$ 4,778,142
Liabilities	$ 2,589,630	2,589,630	2,687,880
Number of assets sold | facility	0
Aggregate sale price		12,750
Noncontrolling interests in subsidiaries	$ 8,597	8,597	$ 8,632
VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	6
Assets	$ 136,485	136,485
Liabilities	$ 52,666	52,666
CS Vienna LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	72.00%
Assets	$ 17,865	17,865
Liabilities	$ 6,553	6,553
CS 750 W Merrick Rd LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	51.00%
Assets	$ 15,626	15,626
Liabilities	$ 8,181	8,181
CS Valley Forge Village Storage LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	70.00%
Assets	$ 20,654	20,654
Liabilities	$ 12,333	12,333
CS 2087 Hempstead Tpk LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	51.00%
Assets	$ 24,336	24,336
Liabilities	$ 7,104	7,104
CS SDP Newtonville LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	90.00%
Assets	$ 18,345	18,345
Liabilities	$ 11,828	11,828
SH3, LLC | VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	1
Ownership interest held by the entity (as a percent)	90.00%
Assets	$ 39,659	39,659
Liabilities	6,667	6,667
VIE | CS Vienna LLC
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans	5,400	5,400
Amount of mortgage loan commitment	17,000	17,000
VIE | CS 750 W Merrick Rd LLC
Interests in Consolidated Real Estate Joint Ventures
Option to put ownership interest in the venture	$ 17,100
Period of option to call ownership interest of another member	1 year
Period of option to put ownership interest in venture	2 years
Option to call ownership interest of another member	$ 17,100
Initiation period for the call option	12 months
Accretion liability	$ 7,300
VIE | CS Valley Forge Village Storage LLC
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans	9,600	9,600
Amount of mortgage loan commitment	12,400	12,400
VIE | CS 2087 Hempstead Tpk LLC
Interests in Consolidated Real Estate Joint Ventures
Option to put ownership interest in the venture	6,600
Option to call ownership interest of another member	6,600
Accretion liability	6,200
VIE | CS SDP Newtonville LLC
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans	11,100	11,100
Amount of mortgage loan commitment	$ 12,100	$ 12,100
VIE | SH3, LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated | facility	2

NONCONTROLLING INTERESTS - Oper

NONCONTROLLING INTERESTS - Operating Partnership Ownership (Details) - USD ($)	Sep. 29, 2020	Jul. 20, 2020	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Operating Partnership Ownership
OP Units outstanding which are not owned by the general partner (as a percent)			3.60%	3.50%		3.60%
OP units outstanding (in shares)			7,420,828	7,365,828		7,420,828
Adjustment for noncontrolling interest in the Operating Partnership				$ (32,102,000)	$ 7,976,000	$ (4,200,000)
New York
Operating Partnership Ownership
Purchase Price		$ 9,500,000
Total consideration	$ 10,000,000
Cash paid for acquisition	$ 1,000,000
Units issued (in shares)	276,497
Units issued	$ 9,000,000
Storage Deluxe assets
Operating Partnership Ownership
Purchase Price			$ 540,000,000
Number of tranches			$ 2
Units issued (in shares)			5,272,023
Units issued			$ 175,100,000
Cubesmart, L P and Subsidiaries
Operating Partnership Ownership
Adjustment for noncontrolling interest in the Operating Partnership				$ (32,102,000)	$ 7,976,000

LEASES - Narrative (Details)

LEASES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
LEASES
Lessor, Administrative and late fees income	$ 4,800	$ 5,400
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Lessee, Operating Lease, Existence of Option to Terminate [true false]	true
Operating leases - Right-of-use assets	$ 54,989		$ 55,302
Operating lease liabilities	$ 53,541		$ 53,595
Weighted-average remaining lease term - operating leases	34 years 7 months 6 days		34 years 9 months 18 days
Weighted-average discount rate - operating leases	4.47%		4.46%
Operating lease amount paid	$ 500	$ 600
Maximum
LEASES
Operating and Finance lease term (in years)	44 years
Operating and Finance lease renewal term (in years)	69 years

LEASES - Lease Cost (Details)

LEASES - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lease information
Amortization of finance lease right of-of-use assets	$ 241
Interest expense related to finance lease liabilities	526
Operating lease cost	822	$ 746
Short-term lease cost	306	308
Total lease cost	$ 1,895	$ 1,054
Automobiles
Lease information
Lease term	12 months

LEASES - Balance Sheet Informat

LEASES - Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Lease information
Finance leases - Right-of-use assets	$ 41,655	$ 41,896
Finance lease liabilities	65,710	65,599
Operating leases - Right-of-use assets	54,989	55,302
Operating lease liabilities	$ 53,541	$ 53,595
Weighted-average remaining lease term - finance leases	43 years 3 months 18 days	43 years 6 months
Weighted-average remaining lease term - operating leases	34 years 7 months 6 days	34 years 9 months 18 days
Weighted-average discount rate - finance leases	3.25%	3.25%
Weighted-average discount rate - operating leases	4.47%	4.46%

LEASES - Future Operating Lease

LEASES - Future Operating Lease Liability Maturities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Future operating lease liability maturities
2021	$ 1,893
2022	2,639
2023	2,690
2024	2,540
2025	2,539
2026 and thereafter	99,290
Total operating lease payments	111,591
Less: Imputed interest	(58,050)
Operating lease liabilities	53,541		$ 53,595
Operating lease amount paid	500	$ 600
Finance lease, amount paid	400	$ 0
Future finance lease liability maturities
2021	1,520
2022	2,183
2023	2,183
2024	2,183
2025	2,224
2026 and thereafter	122,932
Total lease payments	133,225
Less: Imputed interest	(67,515)
Finance lease liabilities	$ 65,710		$ 65,599

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - Joint ventures related to affiliated real estate investments - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
RELATED PARTY TRANSACTIONS
Management fees	$ 1	$ 0.9
Amounts due to the Company from related parties	15		$ 13.1
Mortgage loans receivable from consolidated joint ventures	26.2		$ 21.4
Ventures
RELATED PARTY TRANSACTIONS
Acquisition fees	$ 0.2	$ 0.7

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent event - Storage Property Located in Minnesota $ in Millions	Apr. 16, 2021USD ($)
Subsequent Events
Ownership interest held by the entity (as a percent)	50.00%
Contribution To Real Estate Venture	$ 3.4
Due from joint ventures	5.5
Maximum
Subsequent Events
Due from joint ventures	$ 6.1

CONSOLIDATED BALANCE SHEETS (LP

CONSOLIDATED BALANCE SHEETS (LP cube) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Storage properties	$ 5,492,183	$ 5,489,754
Less: Accumulated depreciation	(997,712)	(983,940)
Storage properties, net (including VIE assets of $136,141 and $119,345, respectively)	4,494,471	4,505,814
Cash and cash equivalents	3,650	3,592
Restricted cash	2,342	2,637
Loan procurement costs, net of amortization	3,029	3,275
Investment in real estate ventures, at equity	93,797	92,071
Other assets, net	157,189	170,753
Total assets	4,754,478	4,778,142
LIABILITIES AND CAPITAL
Unsecured senior notes, net	2,030,999	2,030,372
Revolving credit facility	52,800	117,800
Mortgage loans and notes payable, net	171,189	216,504
Lease liabilities - finance leases	65,710	65,599
Accounts payable, accrued expenses and other liabilities	166,025	159,140
Distributions payable	70,854	68,301
Deferred revenue	30,974	29,087
Security deposits	1,079	1,077
Total liabilities	2,589,630	2,687,880
Limited Partnership interests of third parties	278,649	249,414
Commitments and contingencies
Capital
Accumulated other comprehensive loss	(613)	(632)
Total liabilities and equity	4,754,478	4,778,142
Cubesmart, L P and Subsidiaries
ASSETS
Storage properties	5,492,183	5,489,754
Less: Accumulated depreciation	(997,712)	(983,940)
Storage properties, net (including VIE assets of $136,141 and $119,345, respectively)	4,494,471	4,505,814
Cash and cash equivalents	3,650	3,592
Restricted cash	2,342	2,637
Loan procurement costs, net of amortization	3,029	3,275
Investment in real estate ventures, at equity	93,797	92,071
Other assets, net	157,189	170,753
Total assets	4,754,478	4,778,142
LIABILITIES AND CAPITAL
Unsecured senior notes, net	2,030,999	2,030,372
Revolving credit facility	52,800	117,800
Mortgage loans and notes payable, net	171,189	216,504
Lease liabilities - finance leases	65,710	65,599
Accounts payable, accrued expenses and other liabilities	166,025	159,140
Distributions payable	70,854	68,301
Deferred revenue	30,974	29,087
Security deposits	1,079	1,077
Total liabilities	2,589,630	2,687,880
Limited Partnership interests of third parties	278,649	249,414
Commitments and contingencies
Capital
Operating Partner	1,878,215	1,832,848
Accumulated other comprehensive loss	(613)	(632)
Total CubeSmart, L.P. capital	1,877,602	1,832,216
Noncontrolling interests in subsidiaries	8,597	8,632
Total capital	1,886,199	1,840,848
Total liabilities and equity	$ 4,754,478	$ 4,778,142

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (Parenthetical) (LP cube) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Storage facilities, net	$ 4,494,471	$ 4,505,814
VIE
Storage facilities, net	136,141	119,345
Cubesmart, L P and Subsidiaries
Storage facilities, net	4,494,471	4,505,814
Cubesmart, L P and Subsidiaries | VIE
Storage facilities, net	$ 136,141	$ 119,345

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (LP cube) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
REVENUES
Rental income	$ 162,476	$ 140,985
Total revenues	188,841	164,081
OPERATING EXPENSES
Property operating expenses	61,228	55,740
Depreciation and amortization	53,810	40,838
General and administrative	10,916	10,365
Total operating expenses	125,954	106,943
Interest:
Interest expense on loans	(19,234)	(18,681)
Loan procurement amortization expense	(1,035)	(754)
Equity in earnings (losses) of real estate ventures	20	(5)
Other	677	619
Total other expense	(19,572)	(18,821)
NET (INCOME) LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS
Operating Partnership interests of third parties	$ (1,549)	$ (383)
Diluted earnings per share attributable to common shareholders (in dollars per share)	$ 0.21	$ 0.20
Weighted-average basic units outstanding (in units)	199,160	193,582
Weighted-average diluted units outstanding (in units)	200,233	194,264
Other Property Related Income
REVENUES
Property related income	$ 19,304	$ 16,902
Property Management Fee Income
REVENUES
Property related income	7,061	6,194
Cubesmart, L P and Subsidiaries
REVENUES
Rental income	162,476	140,985
Total revenues	188,841	164,081
OPERATING EXPENSES
Property operating expenses	61,228	55,740
Depreciation and amortization	53,810	40,838
General and administrative	10,916	10,365
Total operating expenses	125,954	106,943
Interest:
Interest expense on loans	(19,234)	(18,681)
Loan procurement amortization expense	(1,035)	(754)
Equity in earnings (losses) of real estate ventures	20	(5)
Other	677	619
Total other expense	(19,572)	(18,821)
NET INCOME	43,315	38,317
NET (INCOME) LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS
Noncontrolling interest in subsidiaries	(34)	(38)
NET INCOME ATTRIBUTABLE TO CUBESMART L.P.	43,281	38,279
Operating Partnership interests of third parties	(1,549)	(383)
NET INCOME ATTRIBUTABLE TO COMMON UNITHOLDERS	$ 41,732	$ 37,896
Basic earnings per unit attributable to common unitholders	$ 0.21	$ 0.20
Diluted earnings per share attributable to common shareholders (in dollars per share)	$ 0.21	$ 0.20
Weighted-average basic units outstanding (in units)	199,160	193,582
Weighted-average diluted units outstanding (in units)	200,233	194,264
Cubesmart, L P and Subsidiaries | Other Property Related Income
REVENUES
Property related income	$ 19,304	$ 16,902
Cubesmart, L P and Subsidiaries | Property Management Fee Income
REVENUES
Property related income	$ 7,061	$ 6,194

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (LP cube) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other comprehensive income (loss):
Reclassification of realized losses on interest rate swaps	$ 20	$ 20
OTHER COMPREHENSIVE INCOME	20	20
COMPREHENSIVE INCOME	43,335	38,337
Comprehensive income attributable to Operating Partnership interests of third parties	(1,550)	(383)
Comprehensive income attributable to noncontrolling interest in subsidiaries	(34)	(38)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE COMPANY	41,751	37,916
Cubesmart, L P and Subsidiaries
NET INCOME	43,315	38,317
Other comprehensive income (loss):
Reclassification of realized losses on interest rate swaps	20	20
OTHER COMPREHENSIVE INCOME	20	20
COMPREHENSIVE INCOME	43,335	38,337
Comprehensive income attributable to Operating Partnership interests of third parties	(1,550)	(383)
Comprehensive income attributable to noncontrolling interest in subsidiaries	(34)	(38)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE COMPANY	$ 41,751	$ 37,916

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITAL (LP cube) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Increase (Decrease) in Partners' Capital
Balance of Noncontrolling Interests in the Operating Partnership	$ 249,414
Distributions paid to noncontrolling interests in subsidiaries	(69)	$ (59)
Adjustment for Operating Partnership interests of third parties	(32,102)	7,976	$ (4,200)
Net income (loss)	41,766	37,934
Other comprehensive income (loss), net	19	20
Balance of Noncontrolling Interests in the Operating Partnership	278,649		249,414
Noncontrolling Interests in Operating Partnership
Increase (Decrease) in Partners' Capital
Balance of Noncontrolling Interests in the Operating Partnership	249,414	62,088	62,088
Adjustment for Operating Partnership interests of third parties	32,102	(7,976)
Net income (loss)	1,549	383
Other comprehensive income (loss), net	1
Balance of Noncontrolling Interests in the Operating Partnership	278,649	53,845	249,414
Cubesmart, L P and Subsidiaries
Increase (Decrease) in Partners' Capital
Balance	1,840,848	1,807,336	1,807,336
Balance of Noncontrolling Interests in the Operating Partnership	249,414
Distributions paid to noncontrolling interests in subsidiaries	(69)	(59)
Issuance of common OP units	99,688
Issuance of common OP units		(118)
Conversion from OP units to shares	1,913
Exercise of OP unit options	1,172
Amortization of restricted OP units	705	710
OP unit compensation expense	609	530
Adjustment for Operating Partnership interests of third parties	(32,102)	7,976
Net income (loss)	41,766	37,934
Other comprehensive income (loss), net	19	20
Common OP unit distributions	(68,350)	(64,039)
Balance	1,886,199	1,790,290	1,840,848
Balance of Noncontrolling Interests in the Operating Partnership	278,649		249,414
Cubesmart, L P and Subsidiaries | Noncontrolling Interests in Operating Partnership
Increase (Decrease) in Partners' Capital
Balance of Noncontrolling Interests in the Operating Partnership	249,414	62,088	62,088
Conversion from OP units to shares	(1,913)
Adjustment for Operating Partnership interests of third parties	32,102	(7,976)
Net income (loss)	1,549	383
Other comprehensive income (loss), net	1
Common OP unit distributions	(2,504)	(650)
Balance of Noncontrolling Interests in the Operating Partnership	278,649	53,845	249,414
Cubesmart, L P and Subsidiaries | Total Shareholders' Equity
Increase (Decrease) in Partners' Capital
Balance	1,832,216	1,799,346	1,799,346
Issuance of common OP units	99,688
Issuance of common OP units		(118)
Conversion from OP units to shares	1,913
Exercise of OP unit options	1,172
Amortization of restricted OP units	705	710
OP unit compensation expense	609	530
Adjustment for Operating Partnership interests of third parties	(32,102)	7,976
Net income (loss)	41,732	37,896
Other comprehensive income (loss), net	19	20
Common OP unit distributions	(68,350)	(64,039)
Balance	1,877,602	1,782,321	1,832,216
Cubesmart, L P and Subsidiaries | Operating Partner
Increase (Decrease) in Partners' Capital
Balance	$ 1,832,848	$ 1,800,075	$ 1,800,075
Balance (in units)	197,406	193,557	193,557
Issuance of common OP units	$ 99,688
Issuance of common OP units (in units)	2,837
Issuance of restricted OP units (in units)	32	30
Issuance of common OP units		$ (118)
Conversion from OP units to shares	$ 1,913
Conversion from OP units to shares (in units)	55
Exercise of OP unit options	$ 1,172
Exercise of OP unit options (in units)	92
Amortization of restricted OP units	$ 705	710
OP unit compensation expense	609	530
Adjustment for Operating Partnership interests of third parties	(32,102)	7,976
Net income (loss)	41,732	37,896
Common OP unit distributions	(68,350)	(64,039)
Balance	$ 1,878,215	$ 1,783,030	$ 1,832,848
Balance (in units)	200,422	193,587	197,406
Cubesmart, L P and Subsidiaries | Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Partners' Capital
Balance	$ (632)	$ (729)	$ (729)
Other comprehensive income (loss), net	19	20
Balance	(613)	(709)	(632)
Cubesmart, L P and Subsidiaries | Noncontrolling Interest in Subsidiaries
Increase (Decrease) in Partners' Capital
Balance	8,632	7,990	7,990
Distributions paid to noncontrolling interests in subsidiaries	(69)	(59)
Net income (loss)	34	38
Balance	$ 8,597	$ 7,969	$ 8,632

CONSOLIDATED STATEMENTS OF EQ_3

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) (LP cube) - $ / shares	Mar. 31, 2020	Mar. 31, 2019
Cubesmart, L P and Subsidiaries
Common OP unit distributions (in dollars per share)	$ 0.34	$ 0.33

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (LP cube) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Activities
Net income	$ 43,315	$ 38,317
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	54,845	41,592
Non-cash portion of interest expense related to finance leases	111
Equity in (earnings) losses of real estate ventures	(20)	5
Equity compensation expense	2,042	1,871
Accretion of fair market value adjustment of debt	(607)	(176)
Changes in other operating accounts:
Other assets	(1,718)	2,743
Accounts payable and accrued expenses	(1,675)	(3,743)
Other liabilities	1,889	340
Net cash provided by operating activities	98,182	80,949
Investing Activities
Acquisitions of storage properties		(9,090)
Additions and improvements to storage properties	(7,894)	(11,923)
Development costs	(10,932)	(9,709)
Investment in real estate ventures	(6,664)	(5,877)
Cash distributed from real estate ventures	4,958	1,815
Net cash used in investing activities	(20,532)	(34,784)
Proceeds from:
Revolving credit facility	268,111	5,127
Principal payments on:
Revolving credit facility	(333,111)	(5,127)
Mortgage loans and notes payable	(44,649)	(633)
Cash paid upon vesting of restricted OP units	(728)	(631)
Distributions paid to noncontrolling interests in subsidiaries	(69)	(59)
Distributions paid to common OP unitholders	(67,368)	(64,036)
Net cash provided by financing activities	(77,887)	(66,127)
Change in cash, cash equivalents and restricted cash	(237)	(19,962)
Cash, cash equivalents and restricted cash at beginning of period	6,229	58,441
Cash, cash equivalents and restricted cash at end of period	5,992	38,479
Supplemental Cash Flow and Noncash Information
Cash paid for interest, net of interest capitalized	23,534	23,652
Supplemental disclosure of noncash activities:
Accretion of put liability	2,823	896
Derivative valuation adjustment	(20)	(20)
Cubesmart, L P and Subsidiaries
Operating Activities
Net income	43,315	38,317
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	54,845	41,592
Non-cash portion of interest expense related to finance leases	111
Equity in (earnings) losses of real estate ventures	(20)	5
Equity compensation expense	2,042	1,871
Accretion of fair market value adjustment of debt	(607)	(176)
Changes in other operating accounts:
Other assets	(1,718)	2,743
Accounts payable and accrued expenses	(1,675)	(3,743)
Other liabilities	1,889	340
Net cash provided by operating activities	98,182	80,949
Investing Activities
Acquisitions of storage properties		(9,090)
Additions and improvements to storage properties	(7,894)	(11,923)
Development costs	(10,932)	(9,709)
Investment in real estate ventures	(6,664)	(5,877)
Cash distributed from real estate ventures	4,958	1,815
Net cash used in investing activities	(20,532)	(34,784)
Proceeds from:
Revolving credit facility	268,111	5,127
Principal payments on:
Revolving credit facility	(333,111)	(5,127)
Mortgage loans and notes payable	(44,649)	(633)
Proceeds from issuance of common OP units	99,688	(118)
Cash paid upon vesting of restricted OP units	(728)	(631)
Exercise of OP unit options	1,172
Distributions paid to noncontrolling interests in subsidiaries	(69)	(59)
Distributions paid to common OP unitholders	(68,301)	(64,686)
Net cash provided by financing activities	(77,887)	(66,127)
Change in cash, cash equivalents and restricted cash	(237)	(19,962)
Cash, cash equivalents and restricted cash at beginning of period	6,229	58,441
Cash, cash equivalents and restricted cash at end of period	5,992	38,479
Supplemental Cash Flow and Noncash Information
Cash paid for interest, net of interest capitalized	23,534	23,652
Supplemental disclosure of noncash activities:
Accretion of put liability	2,823	896
Derivative valuation adjustment	$ 20	$ 20