IRON MOUNTAIN INC — Director's Dealing 2021

May 25, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: IRON MOUNTAIN INC (IRM)
CIK: 0001020569
Period of Report: 2021-05-24

Reporting Person: Borges Daniel (SVP & Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-24	Common Stock, par value $.01 per share	M	509	—	Acquired	1831	Direct
2021-05-24	Common Stock, par value $.01 per share	F	147	$43.69	Disposed	1684	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-05-24	Restricted Stock Units	$	M	509	Disposed		Common Stock (509.0)	Direct

Footnotes

F1: This acquisition is reported to reflect the partial vesting of restricted stock units ("RSUs") previously granted to the Reporting Person on May 23, 2018.

F2: Each RSU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock").

F3: The RSUs, representing a contingent right to receive a total of 1,521 shares of Common Stock, were granted to the Reporting Person on May 23, 2018 and is fully vested.