Barry A. Hytinen - 01 Mar 2026 Form 4 Insider Report for IRON MOUNTAIN INC (IRM)

Role: EVP and CFO
Signature: Barry A. Hytinen
Issuer symbol: IRM
Transactions as of: 01 Mar 2026
Net transactions value: -$11,360,784
Form type: 4
Filing time: 03 Mar 2026, 18:48:45 UTC
Previous filing: 18 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Hytinen Barry	EVP and CFO	C/O IRON MOUNTAIN INCORPORATED, 85 NEW HAMPSHIRE AVENUE, SUITE 150, PORTSMOUTH	Barry A. Hytinen	03 Mar 2026	0001613777

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	IRM	Common Stock, par value $.01 per share	Options Exercise	$0	+232,977	+117%	$0.000000	431,495	01 Mar 2026	Direct	F1
transaction	IRM	Common Stock, par value $.01 per share	Tax liability	$11,360,784	-104,872	-24%	$108.33	326,623	01 Mar 2026	Direct	F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	IRM	Performance Units	Options Exercise	$0	-232,977	-100%	$0.000000	0	01 Mar 2026	Common Stock, par value $.01 per share	232,977		Direct	F3, F4

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	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.
F3	Each PU represents a contingent right to receive one share of Common Stock.
F4	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.