X0306 4 2015-06-05 0 0001075415 SENIOR HOUSING PROPERTIES TRUST NYSE: SNH 0001241559 PORTNOY BARRY M 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 2015-06-05 4 A 0 8673.5 20.02 A 112760.45 I See Footnote Common Shares of Beneficial Interest 2015-06-05 4 J 0 1289750 19.95 A 1402510.45 I See Footnote Common Shares of Beneficial Interest 286814.076 D These Common Shares were issued as a portion of the management fee paid by the Issuer pursuant to the business management agreement between the Issuer and Reit Management & Research LLC ("RMR LLC") in effect as of the date of the transaction at $20.02, the average of the closing prices of the Common Shares on the New York Stock Exchange for each trading day during the month of May 2015. On May 19, 2015, RMR LLC distributed all of the Common Shares of the Issuer it then directly owned to Reit Management & Research Trust ("RMR Trust"), then its sole member. Mr. Portnoy is the Chairman, majority beneficial owner and a trustee of RMR Trust. Represents the pecuniary interest of Mr. Portnoy in Common Shares owned by RMR Trust. On June 5, 2015, RMR Trust, RMR LLC, Reit Management & Research Inc. and the Issuer entered into a Transaction Agreement for an Up-C transaction pursuant to which, among other things, RMR Trust acquired 2,345,000 newly issued Common Shares valued at $19.95 per share, the volume weighted average trading price per Common Share on the New York Stock Exchange during the 20 business days prior to the closing of the transactions contemplated by the Transaction Agreement. Includes 5,414.343 shares acquired under the Senior Housing Properties Trust Dividend Reinvestment Plan since the last Section 16 filing by Mr. Portnoy. /s/ Barry M. Portnoy 2015-06-09