SCHEDULE 13G/A Filing for Iron Mountain Inc. by The Vanguard Group

This filing details The Vanguard Group's updated beneficial ownership of Iron Mountain Inc. common stock as of March 13, 2026. The filing, an amendment (No. 12) to a previous Schedule 13G, indicates that The Vanguard Group, including its managed accounts and investment companies, has the right to receive or direct the receipt of dividends and the proceeds from the sale of the reported securities. However, it explicitly states that no single other person holds more than a 5% interest in the reported securities. The filing also notes an internal realignment within The Vanguard Group as of January 12, 2026, leading to a disaggregated reporting of beneficial ownership by certain subsidiaries and business divisions, in accordance with SEC Release No. 34-39538. Following this realignment, The Vanguard Group, Inc. no longer holds or is deemed to hold beneficial ownership over securities held by these subsidiaries and divisions.