X0303 4/A 2011-03-30 2011-03-31 0 0001075415 SENIOR HOUSING PROPERTIES TRUST NYSE: SNH 0001273871 PORTNOY ADAM C/O REIT MANAGEMENT & RESEARCH LLC TWO NEWTON PL., 255 WASH. ST., STE. 300 NEWTON MA 02458 1 0 0 0 Common Shares of Beneficial Interest 2011-03-30 5 J 0 E 4023 23.02 A 102779.55 D These shares were issued pursuant to a business management agreement between the issuer and Reit Management & Research LLC ("RMR") of which Mr. Portnoy is a director and minority beneficial owner. Mr. Portnoy purchased these shares from RMR upon their issuance. Such transfers were exempt from Section 16 of the Securities Exchange Act of 1934, as amended, pursuant to Rule 16a-13 thereunder. In accordance with the business management agreement referred to above, certain historical share price information was used to determine the number of common shares of beneficial interest paid to RMR. The per share price amount listed above is the closing sale price of the issuer's common shares of beneficial interest on the New York Stock Exchange on March 30, 2011, when the shares were issued and purchased. This amendment is being filed to include Mr. Portnoy's street address, which was omitted due to an error by the filing administrator. /s/ Adam D. Portnoy 2011-04-01