Eighteenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of May 22, 2019, effective as of April 1, 2019, among certain subsidiaries of the Company, as Landlord, and certain subsidiaries of Five Star Senior Living Inc., as Tenant

THIS EIGHTEENTH AMENDMENT TO AMENDED AND RESTATED MASTER LEASE AGREEMENT (LEASE NO. 1) (this “Amendment”) is made and entered into as of May 22, 2019, by and among each of the parties identified on the signature pages hereof as a landlord (collectively, “Landlord”) and each of the parties identified on the signature pages hereof as a tenant (jointly and severally, “Tenant”).

WHEREAS, pursuant to the terms of that certain Amended and Restated Master Lease Agreement (Lease No. 1), dated as of August 4, 2009, as amended by that certain Partial Termination of and First Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of October 1, 2009, that certain Second Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of November 17, 2009, that certain Third Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of December 10, 2009, that certain Partial Termination of and Fourth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of August 1, 2010, that certain Fifth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of May 1, 2011, that certain Partial Termination of and Sixth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of June 1, 2011, that certain Seventh Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of June 20, 2011, that certain Eighth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of August 31, 2012, that certain Partial Termination of and Ninth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of August 1, 2013, that certain Partial Termination of and Tenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of January 22, 2014, that certain Partial Termination of and Eleventh Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of October 1, 2014, that certain Partial Termination of and Twelfth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of October 31, 2014, that certain Partial Termination of and Thirteenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of February 17, 2015, that certain Partial Termination of and Fourteenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of August 1, 2015, that certain Partial Termination of and Fifteenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of December 29, 2015, that certain Partial Termination of and Sixteenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of June 1, 2018, and that certain Partial Termination of and Seventeenth Amendment to Amended and Restated Master Lease Agreement (Lease No. 1), dated as of May 1, 2019 (as so amended, “Amended Lease No. 1”), Landlord leases to Tenant, and Tenant leases from Landlord, the Leased Property (this and other capitalized terms used but not otherwise defined herein having the meanings given such terms in Amended Lease No. 1), all as more particularly described in Amended Lease No. 1; and

WHEREAS, Amended Lease No. 1 was further modified by that certain Transaction Agreement, dated as of April 1, 2019, between Five Star Senior Living Inc., on behalf of itself and certain of its subsidiaries, and Senior Housing Properties Trust, on behalf of itself and certain of its subsidiaries (the “Transaction Agreement”); and