X0609 4 2026-10-01 0 0001020569 IRON MOUNTAIN INC IRM 0001566391 Meaney William L false 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 2026-10-01 4 M 0 38474 37 A 38474 D Common Stock, par value $.01 per share 2026-10-01 4 S 0 13358 109.57 D 25116 D Common Stock, par value $.01 per share 2026-10-01 4 S 0 10808 110.56 D 14308 D Common Stock, par value $.01 per share 2026-10-01 4 S 0 14308 111.18 D 0 D Common Stock, par value $.01 per share 82970 I By Meaney 2024 Master Trust Common Stock, par value $.01 per share 212680 I By Meaney Master Trust #2 Employee Stock Option (Right to Buy) 37 2026-10-01 4 M 0 38474 D 2027-02-16 Common Stock, par value $.01 per share 38474 76948 D This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 14, 2025. 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 $109.02 to $110.00, 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 Iron Mountain Incorporated Common Stock were sold in multiple transactions at prices ranging from $110.02 to $111.02, 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 Iron Mountain Incorporated Common Stock were sold in multiple transactions at prices ranging from $111.03 to $111.55, 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) This stock option, initially representing a right to purchase a total of 461,696 shares, is fully vested. Not applicable. /s/ Christine Zhang, under Power of Attorney dated February 27, 2025, from William Meaney 2026-10-05