BAILEY CLARK H

SEC source: 0001020569-25-000154 · wk-form4_1751574198.xml · derivative · entry 4

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 90,860.989 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock. The Reporting Person ceased service as a director effective May 29, 2025.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock. The Reporting Person ceased service as a director effective May 29, 2025.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock. The Reporting Person ceased service as a director effective May 29, 2025.

SEC source: 0001020569-25-000154 · wk-form4_1751574198.xml · nonDerivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 242,454.989

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock. The Reporting Person ceased service as a director effective May 29, 2025.

SEC source: 0001020569-25-000080 · wk-form4_1744063558.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 90,860.989

Underlying: Common Stock · 883.056 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Common Stock were acquired in multiple transactions at prices ranging from $79.524 to $80.259, 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.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-25-000021 · wk-form4_1736371825.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 89,977.933

Underlying: Common Stock · 616.743 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $103.329 to $103.734, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-24-000241 · wk-form4_1728334565.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 89,361.19

Underlying: Common Stock · 534.228 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $118.729 to $119.114, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-24-000188 · wk-form4_1720490211.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 88,826.962

Underlying: Common Stock · 620.705 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $92.129 to $92.459, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-24-000155 · wk-form4_1717449771.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 88,206.257

Underlying: Common Stock · 2,385 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 30, 2024, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 30, 2024, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 30, 2024, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

SEC source: 0001020569-24-000091 · wk-form4_1712349740.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 85,821.257

Underlying: Common Stock · 690.932 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $79.989 to $80.149, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-24-000012 · wk-form4_1704754302.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 85,130.325

Underlying: Common Stock · 814.026 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated common stock ("Common Stock") were sold in multiple transactions at prices ranging from $67.269 to $67.379, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-23-000199 · wk-form4_1696971804.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 84,316.299

Underlying: Common Stock · 937.959 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated Common Stock were purchased in multiple transactions at prices ranging from $57.639 to $57.869, 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 purchased at each separate price within the ranges set forth in this footnote (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-23-000149 · wf-form4_168902852586546.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 83,378.34

Underlying: Common Stock · 886.276 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated Common Stock were purchased in multiple transactions at prices ranging from $57.50 to $57.60, 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 purchased at each separate price within the ranges set forth in this footnote (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-23-000120 · wf-form4_168376796381918.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 82,492.064

Underlying: Common Stock · 3,047 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 9, 2023, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 9, 2023, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 9, 2023, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-23-000093 · wf-form4_168089979491495.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 79,445.064

Underlying: Common Stock · 923.247 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F3 · price: The price reported in Column 8 is a weighted average price. These shares of Iron Mountain Incorporated Common Stock were sold in multiple transactions at prices ranging from $52.52 to $52.71, 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 (3).

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-23-000015 · wf-form4_167330040500704.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 78,521.817

Underlying: Common Stock · 967.37 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-22-000191 · wf-form4_166500436689350.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 77,554.447

Underlying: Common Stock · 988.633 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-22-000150 · wf-form4_165834891072030.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 76,565.814

Underlying: Common Stock · 945.086 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F3 · balance_after: Includes an additional 2.7236 Phantom Shares to reconcile total beneficial ownership from prior reported transactions.

SEC source: 0001020569-22-000118 · wf-form4_165247466477056.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,436.1695

Underlying: Common Stock · 3,300 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 10, 2022, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 10, 2022, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 10, 2022, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-22-000098 · wf-form4_164972647909894.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 67,136.1695

Underlying: Common Stock · 786.8356 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-22-000013 · wf-form4_164186726793413.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 66,349.3339

Underlying: Common Stock · 849.5592 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-21-000229 · wf-form4_163372779732276.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 65,499.7747

Underlying: Common Stock · 981.1447 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-21-000185 · wf-form4_162577542904272.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 64,518.63

Underlying: Common Stock · 999.6751 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-21-000157 · wf-form4_162102443136749.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,518.9549

Underlying: Common Stock · 3,933 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

SEC source: 0001020569-22-000148 · wf-form4a_165834787772557.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 68,700.7898

Underlying: Common Stock · 3,933 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 12, 2021, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F2 · balance_after: The amount of Phantom Shares beneficially owned was incorrectly disclosed due to a calculation error. This amendment corrects the number of beneficially owned shares following the reported transaction from 63,518.9549 to 68,700.7898.

SEC source: 0001020569-21-000119 · wf-form4_161791672848624.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 64,767.7898

Underlying: Common Stock · 1,060.1272 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-21-000017 · wf-form4_161015523997149.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,707.6626

Underlying: Common Stock · 1,295.8107 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-20-000201 · wf-form4_160201724045324.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 62,411.8519

Underlying: Common Stock · 1,394.6091 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-20-000178 · wf-form4_159441503999326.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 61,017.2428

Underlying: Common Stock · 1,431.2879 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-20-000156 · wf-form4_158958039409461.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 59,585.9549

Underlying: Common Stock · 7,011 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 13, 2020, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 13, 2020, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 13, 2020, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

SEC source: 0001020569-20-000118 · wf-form4_158637998609340.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,574.9549

Underlying: Common Stock · 1,444.1169 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-20-000039 · wf-form4_158207894864200.xml · derivative · entry 5

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 15,555 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_date: This stock option, representing a right to purchase a total of 15,555 shares, is fully vested. The number of stock options granted includes previously reported adjustments effective on September 26, 2014 made in connection with the Special Distribution.

F4 · derivative.expiration_date: This stock option, representing a right to purchase a total of 15,555 shares, is fully vested. The number of stock options granted includes previously reported adjustments effective on September 26, 2014 made in connection with the Special Distribution.

SEC source: 0001020569-20-000039 · wf-form4_158207894864200.xml · nonDerivative · entry 2

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 151,594

F1 · price: 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 $32.76 to $32.78, 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 (1).

SEC source: 0001020569-20-000039 · wf-form4_158207894864200.xml · nonDerivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 167,149

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001020569-20-000012 · wf-form4_157835498706819.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,130.838

Underlying: Common Stock · 974.9277 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-19-000210 · wf-form4_157021938720933.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,155.9103

Underlying: Common Stock · 932.5196 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-19-000185 · wf-form4_156235782496216.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 49,223.3907

Underlying: Common Stock · 952.685 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-19-000165 · wf-form4_155873292488539.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,270.7057

Underlying: Common Stock · 5,060 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 22, 2019, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 22, 2019, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on May 22, 2019, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock

SEC source: 0001020569-19-000120 · wf-form4_155441665479391.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 43,210.7057

Underlying: Common Stock · 726.168 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-19-000062 · wf-form4_155071329965346.xml · derivative · entry 5

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 9,108 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_date: This stock option, representing a right to purchase a total of 9,108 shares, is fully vested. The number of stock options granted includes previously reported adjustments effective on September 26, 2014 made in connection with the special distribution declared by the Board of Directors of the Issuer on September 15, 2014 and paid on November 4, 2014.

F3 · derivative.expiration_date: This stock option, representing a right to purchase a total of 9,108 shares, is fully vested. The number of stock options granted includes previously reported adjustments effective on September 26, 2014 made in connection with the special distribution declared by the Board of Directors of the Issuer on September 15, 2014 and paid on November 4, 2014.

SEC source: 0001020569-19-000062 · wf-form4_155071329965346.xml · nonDerivative · entry 2

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 151,594

SEC source: 0001020569-19-000062 · wf-form4_155071329965346.xml · nonDerivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 160,702

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001020569-19-000005 · wf-form4_154689876880453.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,484.5377

Underlying: Common Stock · 786.6363 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-18-000103 · wf-form4_153869313619403.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,697.9014

Underlying: Common Stock · 704.4955 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001020569-18-000097 · wf-form4_153575204640446.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,993.4059

Underlying: Common Stock · 75.5 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: The Reporting Person was eligible to receive but, as a result of an error in connection with the administration of the Plan, did not receive the dividend previously paid on Common Stock on July 2, 2018 (the "Dividend"), with respect to those certain restricted stock units granted to the Reporting Person on June 18, 2018 (the "RSUs"). The administrator of the Plan completed this transaction to give retroactive effect to the Dividend solely with respect to the RSUs.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: The Reporting Person was eligible to receive but, as a result of an error in connection with the administration of the Plan, did not receive the dividend previously paid on Common Stock on July 2, 2018 (the "Dividend"), with respect to those certain restricted stock units granted to the Reporting Person on June 18, 2018 (the "RSUs"). The administrator of the Plan completed this transaction to give retroactive effect to the Dividend solely with respect to the RSUs.

SEC source: 0001104659-18-044058 · a4.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,917.9059

Underlying: Common Stock · 612.7997 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001104659-18-040900 · a4.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: Not disclosed

Underlying: Common Stock · 4,413 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on June 14, 2018, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on June 14, 2018, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on June 14, 2018, which RSUs vest on the grant date, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

SEC source: 0001020569-18-000056 · wf-form4_152521046127613.xml · derivative · entry 5

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 9,261 shares

Expires 2018-06-05

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_date: This stock option, representing a right to purchase a total of 9,261 shares, is fully vested. The number of stock options granted includes previously reported adjustments effective on September 26, 2014 made in connection with the special distribution declared by the Board of Directors of the Issuer on September 15, 2014 and paid on November 4, 2014.

SEC source: 0001020569-18-000056 · wf-form4_152521046127613.xml · nonDerivative · entry 2

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 151,594

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.540 to $34.564, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1).

SEC source: 0001020569-18-000056 · wf-form4_152521046127613.xml · nonDerivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 160,855

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001020569-18-000046 · wf-form4_152287728779472.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,892.1062

Underlying: Common Stock · 634.0719 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

SEC source: 0001104659-18-000826 · a4.xml · derivative · entry 1

BAILEY CLARK H · CIK 0001183331 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,258.0343

Underlying: Common Stock · 536.6089 shares

Expires not disclosed

F1 · derivative.exercise_price: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.

F1 · derivative.exercise_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F1 · derivative.expiration_date: Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of Iron Mountain Incorporated common stock ("Common Stock") following the Reporting Person's disability or cessation of service as a director. Each Phantom Share is the economic equivalent of one share of Common Stock.

F2 · derivative.underlying_shares: These shares give effect to dividends paid on Common Stock as if reinvested in Phantom Shares.