Daniel Borges - 24 May 2021 Form 4 Insider Report for IRON MOUNTAIN INC (IRM)

Role: SVP & Chief Accounting Officer
Signature: /s/ Elizabeth Tammaro, under Power of Attorney dated October 23, 2017 from Daniel Borges
Issuer symbol: IRM
Transactions as of: 24 May 2021
Net transactions value: -$6,422
Form type: 4
Filing time: 25 May 2021, 18:25:15 UTC
Next filing: 30 Jun 2021
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	IRM	Common Stock, par value $.01 per share	Options Exercise	$0	+509	+39%	$0.000000	1,831	24 May 2021	Direct	F1
transaction	IRM	Common Stock, par value $.01 per share	Tax liability	$6,422	-147	-8%	$43.69	1,684	24 May 2021	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	IRM	Restricted Stock Units	Options Exercise	$0	-509	-100%	$0.000000^*	0	24 May 2021	Common Stock	509		Direct	F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
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.