IRM director receives 1,892-share RSU grant

IRON MOUNTAIN INC director Jennifer Allerton reported routine equity compensation activity.

Rhea-AI Filing Summary

IRON MOUNTAIN INC director Jennifer Allerton reported routine equity compensation activity. She received a grant of 1,892 shares of common stock as restricted stock units that vest in full on the May 7, 2026 grant date. In connection with the net settlement of these RSUs, 133 shares were withheld by the company to cover income tax obligations, which the filing states does not represent a sale. After these transactions, she directly holds 13,300 shares of IRON MOUNTAIN INC common stock.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Allerton Jennifer

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Common Stock, par value $.01 per share	1,892	$0.00	$0.00
Exercise Price or Tax Liability	Common Stock, par value $.01 per share	133	$126.81	$17K

Holdings After Transaction: Common Stock, par value $.01 per share — 13,300 shares (Direct)

Footnotes (2)

1. F1. Consists of shares issuable upon the settlement of restricted stock units ("RSUs") granted on May 7, 2026. The RSUs vest in their entirety on the grant date.
2. 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 RSUs and does not represent a sale.

Key Figures

RSU grant: 1,892 shares Tax withholding shares: 133 shares at $126.81 Post-transaction holdings: 13,433 shares

3 metrics

RSU grant 1,892 shares Restricted stock units granted on May 7, 2026

Tax withholding shares 133 shares at $126.81 Shares withheld to satisfy income tax on RSU settlement

Post-transaction holdings 13,433 shares Common stock directly held after reported transactions

Key Terms

restricted stock units ("RSUs"), vest in their entirety, net settlement, income tax withholding obligation, +1 more

5 terms

restricted stock units ("RSUs") financial

"Consists of shares issuable upon the settlement of restricted stock units ("RSUs") granted on May 7, 2026."

Restricted stock units (RSUs) are a company promise to give an employee shares of stock (or cash equivalent) in the future, but only after certain conditions—usually staying with the company for a set time or hitting performance goals—are met. Investors watch RSUs because when they vest they increase the number of shares outstanding and can lead insiders to sell shares, affecting share price, company dilution and the true cost of employee pay.

vest in their entirety financial

"The RSUs vest in their entirety on the grant date."

net settlement financial

"in connection with the net settlement of the RSUs and does not represent a sale."

income tax withholding obligation financial

"withheld by the Issuer to satisfy its income tax withholding obligation in connection with the net settlement"

grant, award, or other acquisition financial

"transaction_code_description: "Grant, award, or other acquisition""

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did IRM director Jennifer Allerton report on this Form 4?

Jennifer Allerton reported a routine equity grant and tax withholding. She received 1,892 IRON MOUNTAIN INC common shares via restricted stock units and had 133 shares withheld by the issuer to cover income tax obligations related to the RSU settlement.

Were any IRM shares actually sold in Jennifer Allerton’s latest Form 4 filing?

No, the filing states the 133 IRM shares were withheld to satisfy income tax withholding on RSU settlement and do not represent a sale. This is a non-market, administrative disposition rather than an open-market sale of shares.

What equity award did Jennifer Allerton receive from IRON MOUNTAIN INC on May 7, 2026?

She received restricted stock units representing 1,892 IRON MOUNTAIN INC common shares. The footnote explains these RSUs were granted on May 7, 2026 and vest in their entirety on the grant date, making them fully vested immediately upon grant.

How many IRM shares does Jennifer Allerton own after these Form 4 transactions?

After the RSU grant and related tax withholding, Jennifer Allerton directly holds 13,433 shares of IRON MOUNTAIN INC common stock. This total reflects the net position following issuance of 1,892 shares and the withholding of 133 shares for income tax obligations.

What does the F transaction code mean in Jennifer Allerton’s IRM Form 4?

The F code indicates shares were disposed to pay exercise price or tax liabilities. Here, 133 IRON MOUNTAIN INC shares were withheld by the issuer to satisfy income tax withholding tied to RSU settlement, which the filing clarifies is not a market sale of stock.

Why is the A transaction code used for part of Jennifer Allerton’s IRM filing?

The A code denotes a grant, award, or other acquisition. In this Form 4, it reflects Jennifer Allerton’s acquisition of 1,892 IRON MOUNTAIN INC common shares through a restricted stock unit grant that vested fully on the grant date.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/11/2026 - 04:39 PM EDT Learn about SEC filing dates

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^*

Allerton Jennifer

(Last) (First) (Middle)

C/O IRON MOUNTAIN INCORPORATED

85 NEW HAMPSHIRE AVENUE, SUITE 150

(Street)

PORTSMOUTH NEW HAMPSHIRE 03801

(City) (State) (Zip)

UNITED STATES

(Country)

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
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/07/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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

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	05/07/2026		A		1,892(1)	A	$0	13,433	D
Common Stock, par value $.01 per share	05/07/2026		F		133(2)	D	$126.81	13,300	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

Explanation of Responses:

1. Consists of shares issuable upon the settlement of restricted stock units ("RSUs") granted on May 7, 2026. The RSUs vest in their entirety on the grant date.

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 RSUs and does not represent a sale.

Remarks:

	/s/ Christine Zhang, under Power of Attorney dated June 19, 2025, from Jennifer Allerton	05/11/2026
	** 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.
* Form 4: SEC 1474 (03-26)