Robin Matlock - 03 Oct 2025 Form 4 Insider Report for IRON MOUNTAIN INC (IRM)

Role
Director
Signature
/s/ Christine Zhang, under Power of Attorney dated May 12, 2025 from Robin Matlock
Issuer symbol
IRM
Transactions as of
03 Oct 2025
Net transactions value
+$778
Form type
4
Filing time
07 Oct 2025, 16:09:18 UTC
Previous filing
02 Sep 2025
Next filing
02 Dec 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Matlock Robin Director C/O IRON MOUNTAIN INCORPORATED, 85 NEW HAMPSHIRE AVENUE, SUITE 150, PORTSMOUTH /s/ Christine Zhang, under Power of Attorney dated May 12, 2025 from Robin Matlock 07 Oct 2025 0001781215

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 Phantom Stock Award $778 +7 +0.75% $104.42 998 03 Oct 2025 Common Stock 7 Direct F1, F2, F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan (the "Plan"), the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") on various dates selected by the Reporting Person or as otherwise provided in the Plan. Each Phantom Share is the economic equivalent of one share of Common Stock.
F2 These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.
F3 The price reported in Column 8 is a weighted average price. These shares of Common Stock were acquired in multiple transactions at prices ranging from $104.349 to $104.524, inclusive. The Reporting Person undertakes to provide Iron Mountain Incorporated (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares of Common Stock acquired at each separate price within the ranges set forth in this footnote (3).