Statement of Changes in Beneficial Ownership (4)

FORM 4

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Meaney William L	2. Issuer Name and Ticker or Trading Symbol IRON MOUNTAIN INC [ IRM ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) President and CEO
(Last)          (First)          (Middle) C/O IRON MOUNTAIN INCORPORATED, ONE FEDERAL STREET	3. Date of Earliest Transaction (MM/DD/YYYY) 2/19/2021
(Street) BOSTON, MA 02110 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $.01 per share	2/19/2021		S		8653 (1)	D	$32.53	196945	D
Common Stock, par value $.01 per share	2/19/2021		M		25517 (2)	A	$0	222462	D
Common Stock, par value $.01 per share	2/19/2021		F		11257	D	$32.17	211205	D
Common Stock, par value $.01 per share	2/22/2021		S		7130 (1)	D	$32.13	204075	D
Common Stock, par value $.01 per share	2/22/2021		M		23096 (3)	A	$0	227171	D
Common Stock, par value $.01 per share	2/22/2021		F		10243	D	$31.81	216928	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(4)	2/19/2021		M			25517	(5)	(5)	Common Stock	25517.0	$0	51036	D
Restricted Stock Units	(6)	2/22/2021		M			23096	(7)	(7)	Common Stock	23096.0	$0	23096	D

Explanation of Responses:
(1)	This transaction was effected pursuant to a 10b5-1 trading plan which was approved and became effective as of May 26,2020.
(2)	This acquisition is reported to reflect the partial vesting of restricted stock units ("RSUs") previously granted to the Reporting Person on February 19, 2020.
(3)	This acquisition is reported to reflect the partial vesting of RSUs previously granted to the Reporting Person on February 20, 2019.
(4)	Each RSU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock").
(5)	The RSUs, representing a contingent right to receive a total of 76,553 shares of Common Stock, were granted to the Reporting Person on February 19, 2020 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date.
(6)	Each RSU represents a contingent right to receive one share of Common Stock.
(7)	The RSUs, representing a contingent right to receive a total of 69,288 shares of Common Stock, were granted to the Reporting Person on February 20, 2019 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Meaney William L C/O IRON MOUNTAIN INCORPORATED ONE FEDERAL STREET BOSTON, MA 02110	X		President and CEO

Signatures
/s/ Elizabeth Tammaro, under Power of Attorney dated May 26, 2016, from William Meaney		2/23/2021
**Signature of Reporting Person		Date