X0508 4 2025-11-03 0 0001020569 IRON MOUNTAIN INC IRM 0001566391 Meaney William L C/O IRON MOUNTAIN INCORPORATED 85 NEW HAMPSHIRE AVENUE, SUITE 150 PORTSMOUTH NH 03801 1 1 0 0 President and CEO 1 Common Stock, par value $.01 per share 2025-11-03 4 M 0 69125 36.588 A 69125 D Common Stock, par value $.01 per share 2025-11-03 4 S 0 22619 102.02 D 46506 D Common Stock, par value $.01 per share 2025-11-03 4 S 0 35678 102.922 D 10828 D Common Stock, par value $.01 per share 2025-11-03 4 S 0 10828 103.689 D 0 D Common Stock, par value $.01 per share 295650 I By GRAT Employee Stock Option (Right to Buy) 36.588 2025-11-03 4 M 0 69125 36.588 D 2026-02-18 Common Stock, par value $.01 per share 69125 69125 D The transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 18, 2023. The price reported in Column 4 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $101.475 to $102.475, 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 sold at each separate price within the ranges set forth in this footnote (2). The price reported in Column 4 is a weighted average price. These shares of Common Stock were sold in multiple transactions at prices ranging from $102.485 to $103.470, inclusive. The Reporting Person undertakes to provide 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 sold at each separate price within the ranges set forth in this footnote (3). The price reported in Column 4 is a weighted average price. These shares of Common Stock were sold in multiple transactions at prices ranging from $103.510 to $103.805, inclusive. The Reporting Person undertakes to provide 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 sold at each separate price within the ranges set forth in this footnote (4) Balance reflects 295,650 shares transferred from the Grantor for funding of a Grantor Retained Annuity Trust on November 29, 2024. This transfer is exempt from Section 16 pursuant to Rule 16a-13. This stock option, representing a right to purchase a total of 829,506 shares, is fully vested. /s/ Christine Zhang, under Power of Attorney dated February 27, 2025, from William Meaney 2025-11-05