IRON MOUNTAIN INC Common Stock Shares Outstanding

• IRON MOUNTAIN INC showed an increase of +0.7% in Common Stock Shares Outstanding from 2024 to 2025.
• This data is from IRON MOUNTAIN INC's annual report (Form 10-K), filed with the SEC on February 12, 2026.
• XBRL data for this metric is available from 2009 to 2025 (17 years of filings). Earlier data may not exist in machine-readable XBRL format as companies adopted electronic filing at different times.
• Quarterly values from 10-Q filings: Q4 2008: 201.93 million shares | Q1 2010: 203.43 million shares | Q2 2010: 201.98 million shares | Q3 2010: 200.43 million shares | Q1 2011: 200.26 million shares | Q2 2011: 202.87 million shares | Q3 2011: 186.62 million shares | Q1 2012: 171.18 million shares | Q2 2012: 171.64 million shares | Q3 2012: 172.13 million shares | Q1 2013: 190.61 million shares | Q2 2013: 191.11 million shares | Q3 2013: 191.21 million shares | Q1 2014: 191.92 million shares | Q2 2014: 192.99 million shares | Q3 2014: 193.68 million shares | Q1 2015: 210.53 million shares | Q2 2015: 210.80 million shares | Q3 2015: 211.08 million shares | Q1 2016: 211.89 million shares | Q2 2016: 263.02 million shares | Q3 2016: 263.43 million shares | Q1 2017: 264.11 million shares | Q2 2017: 264.38 million shares | Q3 2017: 266.88 million shares | Q1 2018: 285.92 million shares | Q2 2018: 286.10 million shares | Q3 2018: 286.22 million shares | Q1 2019: 286.83 million shares | Q2 2019: 287.06 million shares | Q3 2019: 287.14 million shares | Q1 2020: 287.88 million shares | Q2 2020: 288.14 million shares | Q3 2020: 288.16 million shares | Q1 2021: 288.73 million shares | Q2 2021: 289.46 million shares | Q3 2021: 289.55 million shares | Q1 2022: 290.55 million shares | Q2 2022: 290.68 million shares | Q3 2022: 290.69 million shares | Q1 2023: 291.58 million shares | Q2 2023: 291.82 million shares | Q3 2023: 291.93 million shares | Q1 2024: 293.09 million shares | Q2 2024: 293.30 million shares | Q3 2024: 293.43 million shares | Q1 2025: 294.97 million shares | Q2 2025: 295.27 million shares | Q3 2025: 295.50 million shares.
• Over the full 17 years of available data (2009 to 2025), IRON MOUNTAIN INC's Common Stock Shares Outstanding has grown by 45.3%.
• Historical annual values: Fiscal year 2025: 295.79 million shares | Fiscal year 2024: 293.59 million shares | Fiscal year 2023: 292.14 million shares | Fiscal year 2022: 290.83 million shares | Fiscal year 2021: 289.76 million shares | Fiscal year 2020: 288.27 million shares | Fiscal year 2019: 287.30 million shares | Fiscal year 2018: 286.32 million shares | Fiscal year 2017: 283.11 million shares | Fiscal year 2016: 263.68 million shares | Fiscal year 2015: 211.34 million shares | Fiscal year 2014: 209.82 million shares | Fiscal year 2013: 191.43 million shares | Fiscal year 2012: 190.01 million shares | Fiscal year 2011: 172.14 million shares | Fiscal year 2010: 200.06 million shares | Fiscal year 2009: 203.55 million shares.
• Data sourced from SEC EDGAR public filings as of August 6, 2026.

Last verified: August 6, 2026