X0508 4 2025-11-03 0 0001020569 IRON MOUNTAIN INC IRM 0001732058 Kidd Mark C/O IRON MOUNTAIN INCORPORATED 85 NEW HAMPSHIRE AVENUE, SUITE 150 PORTSMOUTH NH 03801 0 1 0 0 EVP, GM Data Centers & ALM 1 Common Stock, par value $.01 per share 2025-11-03 4 S 0 6000 102.51 D 67081 D The transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 20, 2025. /s/ Christine Zhang, under Power of Attorney dated June 19, 2025, from Mark Kidd 2025-11-05