IRON MOUNTAIN INC — Director's Dealing 2021

May 14, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: IRON MOUNTAIN INC (IRM)
CIK: 0001020569
Period of Report: 2021-05-12

Reporting Person: Simons Doyle (Director)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-05-12	Phantom Stock	$	A	3933	Acquired		Common Stock (3933.0)	Direct

Footnotes

F1: 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.