Iron Mountain (IRM) EVP nets shares as 123,144 performance units vest

Rhea-AI Filing Summary

Iron Mountain's EVP and Chief Commercial Officer, Greg W. McIntosh, reported the vesting and settlement of performance-based equity awards. On March 1, 2026, he exercised 123,144 performance units into 123,144 shares of common stock at a stated price of $0.00 per share, reflecting full vesting of a March 1, 2023 grant after the performance period ended and the Compensation Committee approved the award.

To cover income tax withholding on this vesting, 55,617 shares of common stock were withheld by Iron Mountain at $108.33 per share in a tax-withholding disposition, which the company states does not represent a market sale. After these transactions, McIntosh directly owned 85,634 shares of Iron Mountain common stock.

Insider Trade Summary

123,144 shares exercised/converted

Mixed 3 txns

Insider McIntosh Greg W

Role EVP, Chief Commercial Officer

Type	Security	Shares	Price	Value
Exercise	Performance Units	123,144	$0.00	--
Exercise	Common Stock, par value $.01 per share	123,144	$0.00	--
Tax Withholding	Common Stock, par value $.01 per share	55,617	$108.33	$6.02M

Holdings After Transaction: Performance Units — 0 shares (Direct); Common Stock, par value $.01 per share — 141,251 shares (Direct)

Footnotes (1)

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. 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. Each PU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock"). 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.

Form 4 Insider Transactions: What Each Field Means →

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

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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^*

McIntosh Greg W

(Last) (First) (Middle)

C/O IRON MOUNTAIN INCORPORATED

85 NEW HAMPSHIRE AVENUE, 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, Chief Commercial Officer

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		123,144(1)	A	$0	141,251	D
Common Stock, par value $.01 per share	03/01/2026		F		55,617(2)	D	$108.33	85,634	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	(3)	03/01/2026		M			123,144	(4)	(4)	Common Stock, par value $.01 per share	123,144	$0	0	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. 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.

3. Each PU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock").

4. 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.

Remarks:

	/s/ Christine Zhang, under Power of Attorney dated June 19, 2025, from Greg McIntosh	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.
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FAQ

What insider transaction did IRON MOUNTAIN INC (IRM) report for Greg W. McIntosh?

Iron Mountain reported that EVP and Chief Commercial Officer Greg W. McIntosh settled performance units into 123,144 shares of common stock. These shares relate to performance units granted on March 1, 2023 that fully vested after the Compensation Committee determined the final award.

How many IRM shares did Greg W. McIntosh receive from performance unit vesting?

Greg W. McIntosh received 123,144 shares of Iron Mountain common stock upon full vesting of performance units. Each performance unit represented a contingent right to one common share, and the Compensation Committee finalized the actual award before the March 1, 2026 vesting date.

Were any of Greg W. McIntosh’s IRM shares sold in this Form 4 filing?

No market sale occurred; 55,617 Iron Mountain shares were withheld by the company to satisfy income tax obligations. The filing specifies this tax-withholding disposition in connection with net settlement of performance units and clarifies that it does not represent a sale of shares.

What price was used for the IRM tax-withholding shares in Greg W. McIntosh’s filing?

The tax-withholding disposition used a price of $108.33 per Iron Mountain share for 55,617 shares. These shares were withheld by the issuer to cover income tax withholding resulting from the vesting and net settlement of the performance units awarded to McIntosh.

How many IRM shares does Greg W. McIntosh own after these transactions?

After the vesting and tax-withholding transactions, Greg W. McIntosh directly owned 85,634 shares of Iron Mountain common stock. This balance reflects the 123,144 shares received from performance unit settlement minus the 55,617 shares withheld for income tax obligations.

What were the key dates for Greg W. McIntosh’s IRM performance units?

The performance units were initially granted on March 1, 2023. Effective February 16, 2026, the Compensation Committee determined the actual award after the performance period, and the units fully vested on March 1, 2026, triggering the share issuance and related tax withholding.