UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 5, 2009

IRON MOUNTAIN INCORPORATED

(Exact name of registrant as specified in its charter)

DELAWARE

(State or other jurisdiction of incorporation)

1-13045	23-2588479
(Commission File Number)	(IRS Employer Identification No.)

745 Atlantic Avenue

Boston, Massachusetts 02111

(Address of principal executive offices, including zip code)

(617) 535-4766

(Registrant's telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e- 4(c))

Item 8.01. Other Events.

On December 29, 2008, Standard & Poor’s Index Services announced that Iron Mountain Incorporated (the “Company”) will be added to their US S&P 500 Index (the “S&P 500”).  The Company will be added to the S&P 500 GICS (Global Industry Classification Standard) Industrials Economic Sector and the Diversified Support Services Sub-Industry Index.

The Company was formally included in the S&P 500 after the market closed on January 5, 2009.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

IRON MOUNTAIN INCORPORATED (Registrant) By:  /s/ Ernest W. Cloutier
	Name: Ernest W. Cloutier Title:   SVP and General Counsel

Date: January 5, 2009