10-K/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-K/A

Amendment No. 1

x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2006

OR

o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Commission File Number 1-15319

SENIOR HOUSING PROPERTIES TRUST

(Exact Name of Registrant as specified in its Charter)

Maryland	04-3445278
(State of Organization)	(IRS Employer Identification No.)
400 Centre Street, Newton, Massachusetts 02458
(Address of Principal Executive Offices)
617-796-8350
(Registrant’s Telephone Number)
Securities registered pursuant to Section 12(b) of the Act:
Title of each class	Name of each exchange on which registered
Common Shares of Beneficial Interest	New York Stock Exchange
Securities to be registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes xNo o

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o No x

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months, and (2) has been subject to such filing requirements for the past 90 days. Yes x No o

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check One):

Large Accelerated Filer xAccelerated Filer o        Non-Accelerated Filer o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No x

The aggregate market value of the voting shares of the registrant held by non-affiliates was $1.3 billion based on the $17.91 closing price per common share on the New York Stock Exchange on June 30, 2006. For purposes of this calculation, an aggregate of 230,168 common shares held directly or by affiliates of the trustees and officers of the registrant have been included in the number of shares held by affiliates.

Number of the registrant’s common shares outstanding as of February 27, 2007: 83,613,127.

In this Amendment No. 1 to Annual Report on Form 10-K, the terms “SNH”, “Senior Housing”, the “Company”, “we”, “us” and “our” include Senior Housing Properties Trust, and its consolidated subsidiaries, unless the context indicates otherwise.

DOCUMENTS INCORPORATED BY REFERENCE

None.

EXPLANATORY NOTE

We are filing this Amendment No. 1 to our Annual Report on Form 10-K, or Form 10-K/A, to amend Item 15 in our Annual Report on Form 10-K for the fiscal year ended December 31, 2006, or the Annual Report, which was originally filed with the Securities and Exchange Commission on February 28, 2007.

Item 15 of the Annual Report is amended to add summary audited financial information regarding Five Star Quality Care, Inc. for its fiscal years ended December 31, 2004, 2005 and 2006, as reported by that company in its Annual Report on Form 10-K filed with the Securities and Exchange Commission for the fiscal year ended December 31, 2006.  

In addition, we are filing or furnishing, as indicated in this Form 10-K/A, as exhibits certain currently dated certifications.

This amendment is limited in scope to the summary audited financial information described above and does not amend, update, or change any other items or disclosures contained in the Annual Report.  Accordingly, all other items that remain unaffected are omitted in this filing. Except as described in the preceding paragraphs, we do not purport by this Form 10-K/A to update any of the information contained in the Annual Report.

Item 15. Exhibits and Financial Statement Schedules

(a) Index to Financial Statements and Financial Statement Schedules

	Page
1. The following consolidated financial statements and financial statement schedule of Senior Housing Properties Trust are included on the pages indicated:
Reports of Ernst & Young LLP, Independent Registered Public Accounting Firm	F-1
Consolidated Balance Sheet as of December 31, 2006 and 2005	F-4
Consolidated Statement of Income for each of the three years in the period ended December 31, 2006	F-5
Consolidated Statement of Shareholders’ Equity for each of the three years in the period ended December 31, 2006	F-6
Consolidated Statement of Cash Flows for each of the three years in the period ended December 31, 2006	F-7
Notes to Consolidated Financial Statements	F-9
Schedule III - Real Estate and Accumulated Depreciation as of December 31, 2006	S-1
2.  Summary audited financial information for Five Star Quality Care, Inc.	F-1/A

All other schedules for which provision is made in the applicable accounting regulations of the Securities and Exchange Commission are not required under the related instructions, or are inapplicable, and therefore have been omitted.

(b) Exhibits

The following exhibits are filed or furnished with this Form 10-K/A:

Exhibit NumberDescription

31.1	Rule 13a-14(a) Certification. (Filed herewith.)
31.2	Rule 13a-14(a) Certification. (Filed herewith.)
31.3	Rule 13a-14(a) Certification. (Filed herewith.)
31.4	Rule 13a-14(a) Certification. (Filed herewith.)
32.1	Section 1350 Certification. (Furnished herewith.)

Summary Financial Information of Five Star Quality Care, Inc.

The following table presents summary audited financial information for Five Star Quality Care, Inc., or Five Star, for its fiscal years ended December 31, 2004, 2005 and 2006, as reported in its Annual Report on Form 10-K for the fiscal year ended December 31, 2006. Reference is made to Item 1 of our Annual Report on Form 10-K for our fiscal year ended December 31, 2006 for additional information with respect to Five Star.

Summary Financial Information of Five Star Quality Care, Inc.

(in thousands)

	As of or for the year ended
	December 31, 2006			December 31, 2005			December 31, 2004
Total revenues(1)	$	827,337		$	734,023		$	597,824
Net (loss) income		(116,665	)		(84,159	)		3,291
Total assets		366,411			228,940			222,985
Total indebtedness		171,271			45,329			42,581
Total shareholders’ equity		67,430			68,804			95,904

⁽¹⁾ Five Star’s 2006 Annual Report on Form 10-K states that reclassifications were made to the prior years’ financial statements reported therein to conform to the current year’s presentation.

References in this report to the Annual Report on Form 10-K for Five Star are included as textual references only, and the information in such Annual Report is not incorporated by reference into this report.

F-1/A

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, thereunto duly authorized.

SENIOR HOUSING PROPERTIES TRUST

By: /s/ David J. Hegarty

        David J. Hegarty

        President and Chief Operating Officer

        Dated: March 13, 2007

EX-31.1

Exhibit 31.1

CERTIFICATION PURSUANT TO EXCHANGE ACT RULES 13A-14(a) AND 15D-14(a)

I, Barry M. Portnoy, certify that:

1.	I have reviewed this Amendment No. 1 to Annual Report on Form 10-K of Senior Housing Properties Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; and
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report.

Date: March 13, 2007	/s/ Barry M. Portnoy
	Barry M. Portnoy
	Managing Trustee

EX-31.2

Exhibit 31.2

CERTIFICATION PURSUANT TO EXCHANGE ACT RULES 13A-14(a) AND 15D-14(a)

I, Gerard M. Martin, certify that:

1.	I have reviewed this Amendment No. 1 to Annual Report on Form 10-K of Senior Housing Properties Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; and
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report.

Date: March 13, 2007	/s/ Gerard M. Martin
	Gerard M. Martin
	Managing Trustee

EX-31.3

Exhibit 31.3

CERTIFICATION PURSUANT TO EXCHANGE ACT RULES 13A-14(a) AND 15D-14(a)

I, David J. Hegarty, certify that:

1.	I have reviewed this Amendment No. 1 to Annual Report on Form 10-K of Senior Housing Properties Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; and
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report.

Date: March 13, 2007	/s/ David J. Hegarty
	David J. Hegarty
	President and Chief Operating Officer

EX-31.4

Exhibit 31.4

CERTIFICATION PURSUANT TO EXCHANGE ACT RULES 13A-14(a) AND 15D-14(a)

I, John R. Hoadley, certify that:

1.	I have reviewed this Amendment No. 1 to Annual Report on Form 10-K of Senior Housing Properties Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; and
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report.

Date: March 13, 2007	/s/ John R. Hoadley
	John R. Hoadley
	Treasurer and Chief Financial Officer

EX-32.1

Exhibit 32.1

Certification Pursuant to 18 U.S.C. Sec. 1350

(Section 906 of the Sarbanes - Oxley Act of 2002)

_____________________________________________________

In connection with the filing by Senior Housing Properties Trust (the “Company”) of the Amendment No. 1 to the Annual Report on Form 10-K for the period ending December 31, 2006 (the “Report”), each of the undersigned hereby certifies, to the best of his knowledge:

1.	The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
2.	The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Barry M. Portnoy	/s/ David J. Hegarty
Barry M. Portnoy	David J. Hegarty
Managing Trustee	President and Chief Operating Officer
/s/ Gerard M. Martin	/s/ John R. Hoadley
Gerard M. Martin	John R. Hoadley
Managing Trustee	Treasurer and Chief Financial Officer

Date: March 13, 2007