IRON MOUNTAIN INC — Director's Dealing 2021

May 4, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: IRON MOUNTAIN INC (IRM)
CIK: 0001020569
Period of Report: 2021-04-29

Reporting Person: Cloutier Ernest W (EVP & GM, RIM)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-04-29	Common Stock, par value $.01 per share	M	31111	$33.72	Acquired	116208	Direct
2021-04-29	Common Stock, par value $.01 per share	S	31111	$39.9641	Disposed	85097	Direct
2021-04-29	Common Stock, par value $.01 per share	M	25112	$35.72	Acquired	110209	Direct
2021-04-29	Common Stock, par value $.01 per share	S	25112	$39.964	Disposed	85097	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-04-29	Employee Stock Option (Right to Buy)	$33.72	M	31111	Disposed	2028-02-15	Common Stock (31111.0)	Direct
2021-04-29	Employee Stock Option (Right to Buy)	$35.72	M	25112	Disposed	2029-02-20	Common Stock (25112.0)	Direct

Footnotes

F1: This transaction was effected pursuant to a 10b5-1 trading plan which was approved and became effective March1, 2021.

F2: 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 $39.95 to $40.27, 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 (2).

F3: This stock option, representing a right to purchase a total of 31,111 shares, is fully vested.

F4: This stock option, representing a right to purchase a total of 37,668 shares, is fully vested.