Iron Mountain (IRM) EVP vests major stock awards and withholds shares

Rhea-AI Filing Summary

Iron Mountain EVP Mithu Bhargava, head of the Digital Business Unit, reported multiple equity award vestings and related share movements on March 1, 2026. Performance units and restricted stock units converted into common stock, including blocks of 61,113 and 51,919 shares from performance units and several smaller RSU conversions.

The company withheld shares at $108.33 per share to cover income tax obligations tied to these vestings, which footnotes clarify do not represent open‑market sales. After all transactions, Bhargava directly owned 75,779 common shares, including 201 shares acquired through the employee stock purchase plan.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Bhargava Mithu

(Last) (First) (Middle)

C/O IRON MOUNTAIN INCORPORATED

85 NEW HAMPSHIRE AVE, SUITE 150

(Street)

PORTSMOUTH NH 03801

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
IRON MOUNTAIN INC [ IRM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, GM Digital Business Unit

3. Date of Earliest Transaction (Month/Day/Year)
03/01/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

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. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction 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	03/01/2026		M		51,919(1)	A	$0	65,174(2)	D
Common Stock, par value $.01 per share	03/01/2026		F		25,102(3)	D	$108.33	40,072(2)	D
Common Stock, par value $.01 per share	03/01/2026		M		61,113(4)	A	$0	101,185(2)	D
Common Stock, par value $.01 per share	03/01/2026		F		28,205(3)	D	$108.33	72,980(2)	D
Common Stock, par value $.01 per share	03/01/2026		M		2,663(5)	A	$0	75,643(2)	D
Common Stock, par value $.01 per share	03/01/2026		F		1,287(6)	D	$108.33	74,356(2)	D
Common Stock, par value $.01 per share	03/01/2026		M		2,754(7)	A	$0	77,110(2)	D
Common Stock, par value $.01 per share	03/01/2026		F		1,331(6)	D	$108.33	75,779(2)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction 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 (Month/Day/Year)		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: 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
Performance Units	(8)	03/01/2026		M			51,919	(9)	(9)	Common Stock, par value $.01 per share	51,919	$0	0	D
Performance Units	(8)	03/01/2026		M			61,113	(10)	(10)	Common Stock, par value $.01 per share	61,113	$0	0	D
Restricted Stock Units	(11)	03/01/2026		M			2,663	(12)	(12)	Common Stock, par value $.01 per share	2,663	$0	0	D
Restricted Stock Units	(11)	03/01/2026		M			2,754	(13)	(13)	Common Stock, par value $.01 per share	2,754	$0	5,510	D
Restricted Stock Units	(11)	03/01/2026		A		9,692		(14)	(14)	Common Stock, par value $.01 per share	9,692	$0	9,692	D

Explanation of Responses:

1. This acquisition is reported to reflect the full vesting of performance units ("PUs") previously granted to the Reporting Person on March 1, 2023. Effective February 16, 2026, the Compensation Committee of Iron Mountain Incorporated's Board of Directors determined the actual award of PUs under the grant after completion of the relevant performance period, and the PUs fully vested on March 1, 2026.

2. Includes 201 shares of Common Stock acquired under the Iron Mountain Incorporated Employee Stock Purchase Plan since the last Section 16 filing by the Reporting Person.

3. Represents the number of shares of Common Stock that have been withheld by the Issuer to satisfy its income tax withholding obligation in connection with the net settlement of the PUs and does not represent a sale.

4. This acquisition is reported to reflect the full vesting of PUs previously granted to the Reporting Person on July 3, 2023. Effective February 16, 2026, the Compensation Committee of Iron Mountain Incorporated's Board of Directors determined the actual award of PUs under the grant after completion of the relevant performance period, and the PUs fully vested on March 1, 2026.

5. This acquisition is reported to reflect the full vesting of restricted stock units ("RSUs") previously granted to the Reporting Person on March 1, 2023.

6. Represents the number of shares of Common Stock that have been withheld by the Issuer to satisfy its income tax withholding obligation in connection with the net settlement of the RSUs and does not represent a sale.

7. This acquisition is reported to reflect the partial vesting of RSUs previously granted to the Reporting Person on March 1, 2025.

8. Each PU represents a contingent right to receive one share of Common Stock.

9. The PUs were initially granted to the Reporting Person on March 1, 2023. Effective as of February 16, 2026, the Compensation Committee determined the actual award of PUs under the grant after completion of the relevant performance period, and the PUs fully vested on March 1, 2026.

10. The PUs were initially granted to the Reporting Person on July 3, 2023. Effective as of February 16, 2026, the Compensation Committee determined the actual award of PUs under the grant after completion of the relevant performance period, and the PUs fully vested on March 1, 2026.

11. Each RSU represents a contingent right to receive one share of Common Stock.

12. The RSUs, representing a contingent right to receive a total of 7,987 shares of Common Stock, were granted to the Reporting Person on March 1, 2023 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date.

13. The RSUs, representing a contingent right to receive a total of 8,264 shares of Common Stock, were granted to the Reporting Person on March 1, 2025 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date.

14. The RSUs, representing a contingent right to receive a total of 9,692 shares of Common Stock, were granted to the Reporting Person on March 1, 2026 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date.

Remarks:

	/s/ Christine Zhang, under Power of Attorney dated November 19, 2024, from Mithu Bhargava	03/03/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did IRON MOUNTAIN INC (IRM) report for Mithu Bhargava?

Iron Mountain reported that EVP Mithu Bhargava had performance units and restricted stock units vest and convert into common stock. Several blocks, including 61,113 and 51,919 shares, became common stock, alongside smaller RSU settlements on March 1, 2026.

Were any of Mithu Bhargava’s IRM share transactions open-market sales?

No, the filing describes share disposals as tax withholding, not open-market sales. Shares were withheld by Iron Mountain at $108.33 per share to satisfy income tax obligations connected to vesting performance units and restricted stock units.

How many IRON MOUNTAIN INC (IRM) shares did Mithu Bhargava own after these transactions?

After the reported March 1, 2026 transactions, Mithu Bhargava directly owned 75,779 shares of Iron Mountain common stock. This total includes 201 shares acquired under Iron Mountain’s employee stock purchase plan since her prior Section 16 filing.

What equity awards vested for Mithu Bhargava at IRON MOUNTAIN INC?

The filing shows full vesting of performance units granted in March 2023 and July 2023, plus vesting of restricted stock units granted in March 2023 and a partial vesting of RSUs granted in March 2025. New RSUs totaling 9,692 units were also granted in March 2026.

At what price were IRON MOUNTAIN INC (IRM) shares withheld for taxes?

Shares withheld to cover tax obligations were valued at $108.33 per share. These withholdings covered income tax on the net settlement of vested performance units and restricted stock units, and the filing notes they do not constitute sales transactions.

What new restricted stock units did Mithu Bhargava receive from IRON MOUNTAIN INC?

On March 1, 2026, Mithu Bhargava received a grant of 9,692 restricted stock units. According to the footnotes, these RSUs vest in three substantially equal annual installments beginning on the first anniversary of the March 1, 2026 grant date.