Robin Matlock - 21 Jan 2026 Form 4 Insider Report for IRON MOUNTAIN INC (IRM)

Reporting relationship: Director
Issuer ticker: IRM
Reported as of: 21 Jan 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 22 Jan 2026, 17:05:11 UTC
Prior SEC filing: 08 Jan 2026
Next SEC filing: 03 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Christine Zhang, under Power of Attorney dated May 12, 2025 from Robin Matlock

Key filing fact

Robin Matlock filed Form 4 for IRON MOUNTAIN INC (IRM) on 22 Jan 2026.

Key facts

This page summarizes Robin Matlock's Form 4 filing for IRON MOUNTAIN INC (IRM).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 22 Jan 2026, 17:05.

Change

Previous filing in this sequence was filed on 08 Jan 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001781215 Primary reporting owner

Matlock Robin

Relationship: Director
Address: C/O IRON MOUNTAIN INCORPORATED, 85 NEW HAMPSHIRE AVENUE, SUITE 150, PORTSMOUTH
Signature: /s/ Christine Zhang, under Power of Attorney dated May 12, 2025 from Robin Matlock
Signature date: 22 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

IRM transaction

Common Stock, par value $.01 per share

Options Exercise

Transaction value: $0
Shares: +10
Change %: +0.04%
Price: $0.000000
Shares after: 28,559
Date: 21 Jan 2026
Ownership: Direct

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

IRM transaction Derivative

Phantom Stock

Options Exercise

Transaction value: $0
Shares: -10
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 21 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 10
Exercise price
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote 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.

Footnote F2

Settlement of the Phantom Shares is in Common Stock