SCHEDULE 13G/A

IRON MTN INC DEL

Common Stock · CUSIP: 46284V101

Event date: 2025-12-31

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Cohen & Steers, Inc.

  Shares: 19,106,540 · Class: 6.46%

• Cohen & Steers Capital Management, Inc.

  Shares: 18,919,035 · Class: 6.40%

• Cohen & Steers UK Limited

  Shares: 167,379 · Class: 0.06%

• Cohen & Steers Asia Limited

  Shares: 0 · Class: 0.00%

• Cohen & Steers Ireland Limited

  Shares: 20,126 · Class: 0.01%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.