SecProbe.io

Mailstop 3233
September 21 , 2015

Via E -mail
Mr. Roderick Day
Chief Financial Officer
Iron Mountain Incorporated
One Fed eral Street
Boston, MA 02110

Re: Iron Mountain Incorporated
 Form 10-K for the  fiscal year e nded December 31, 2014
Filed February 27, 2015
File No. 1 -13045

            Form 10-Q for the quarterly period ended June 30, 2015
Filed July 30, 2015
File No. 1 -13045

Dear Mr. Day :

We have limited our review  of your filing  to the financial statements and related
disclosures and have the following comments.  In some of our comments, we may ask you to
provide us with information so we may better understand your disclosure.

Please respond to these comments  within ten busine ss days by providing the requested
information or advis e us as soon as possible when you will respond.  If you do not believe our
comments apply to your facts and circumstances, please tell us why in your response.

After reviewing your response to these  comments, we may have  additional comments.

Mr. Roderick Day
Iron Mountain Incorporated
September 21, 2015
Page 2

 Form 10 -K for the fiscal year ended December 31, 2014

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of
Operations

Non-GAAP Measures, page s 39

1. We note the use of Funds from Operations Applicable to Iron Mountain, or FFO
(NAREIT) in your earnings commentary and supplemental information. Please tell us
whether you consider this measure to be a key performance indicator. To the extent this
measure is considered a k ey performance indicator, in future periodic filings please
include the measure as well as the required disclosures in accordance with Item 10(e) of
Regulation S -K within your Management’s Discussion and Analysis.

Financial Statements

Notes to Consolidat ed Financial Statements

Note 2. Summary of Significant Accounting Policies

g. Goodwill and Other Intangible Assets, page 86

2. Please explain to us in greater detail the reason for the $32,265 fair value and other
adjustment made to goodwill and deferred income taxes.  Cite any relevant accounting
literature in your response.

q. Allowance for Doubtful Accounts and Credit Memo Reserves, page 100

3. Please tell us the reasons for your credit memo reserve .  Your response should include a
discussion of the types and frequency of disputes that arise that crea te the need for the
reserve.  Cite any relevant accounting literature in your response.

Form 10 -Q for the quarterly period ended June 30, 2015

Notes to Consolidated Financial Statements

Note 5. Debt, page 30

4. We note that you entered into an accounts receivable securitization program in March
2015.  In future filings, please revise your summary of significant accounting policies to
include the accounting policy that you apply for the accounts receivable securitization
program.

Mr. Roderick Day
Iron Mountain Incorporated
September 21, 2015
Page 3

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules require.   Since the company and its management ar e
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

 In responding to our comments, please provide  a written statement from the company
acknowledging that :

 the company is responsible for the adequacy and accuracy of the disclosure in the filing;

 staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and

 the company may not assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of the United States.

You may contact Isaac Esquivel , Staff Accountant,  at (202) 551 -3395  or the undersigned
at (202) 551 -3438 with any questions.

Sincerely,

        /s/ Robert F. Telewicz, Jr.

 Robert F. Telewic z, Jr.
Accounting Branch Chief
Office of Real Estate and
Commodities