Related Person Transactions

12 Months Ended

Dec. 31, 2025

Related Party Transactions [Abstract]

Related Person Transactions

Related Person Transactions

We have relationships and historical and continuing transactions with RMR, RMR Inc., AlerisLife (including Five Star) and others related to them, including other companies to which RMR or its subsidiaries provide management services and some of which have trustees, directors or officers who are also our Trustees or officers. RMR is a majority owned subsidiary of RMR Inc. The Chair of our Board of Trustees and one of our Managing Trustees, Adam D. Portnoy, is the sole trustee, an officer and the controlling shareholder of ABP Trust, which is the controlling shareholder of RMR Inc., chair of the board of directors, a managing director and the president and chief executive officer of RMR Inc., an officer and employee of RMR and, until the acquisition of AlerisLife by ABP Trust on March 20, 2023, the chair of the board of directors and a managing director of AlerisLife, and currently the sole director of AlerisLife. Christopher J. Bilotto, our other Managing Trustee and President and Chief Executive Officer is also an executive of RMR Inc., Matthew C. Brown, our Chief Financial Officer and Treasurer, is also an executive vice president and the chief financial officer and treasurer of RMR Inc. and an officer of ABP Trust, and each of our officers is also an officer and employee of RMR. Jeffrey C. Leer, the president and chief executive officer of AlerisLife,

is an executive officer of RMR. Some of our Independent Trustees also serve as independent trustees of other public companies to which RMR or its subsidiaries provide management services. Adam D. Portnoy serves as the chair of the board and as a managing trustee of these companies. Other officers of RMR, including Mr. Bilotto, Mr. Brown and certain of our officers, serve as managing trustees, or officers of certain of these companies. In addition, officers of RMR and RMR Inc. serve as our officers and officers of other companies to which RMR or its subsidiaries provide management services. As of December 31, 2025, ABP Trust and Adam D. Portnoy owned 9.8% of our outstanding common shares.

AlerisLife. Until March 20, 2023, we were AlerisLife’s largest stockholder, owning approximately 31.9% of AlerisLife’s outstanding common shares, and ABP Acquisition LLC, or ABP Acquisition, a subsidiary of ABP Trust, together with ABP Trust, owned approximately 6.1% of AlerisLife’s outstanding common shares. Five Star is an operating division of AlerisLife. Prior to December 31, 2025, Five Star managed certain of the senior living communities we own pursuant to the Master Management Agreement. RMR provides management services to both us and AlerisLife. AlerisLife participated in our property insurance program for the senior living communities AlerisLife owned. The premiums AlerisLife paid for this coverage were allocated pursuant to a formula based on the profiles of the properties included in the program. See Note 6 for further information regarding our relationships, agreements and transactions with AlerisLife (including Five Star) and Note 2 for further information regarding our investment in AlerisLife.

In connection with ABP Trust's acquisition of AlerisLife in 2023 pursuant to a tender offer, we tendered all of the AlerisLife common shares that we or our subsidiaries then owned at a price of $1.31 per share, or the Tender Offer Price, subject to the right to purchase AlerisLife common shares at the Tender Offer Price prior to December 31, 2023. Pursuant to an extension of this right, on February 16, 2024, we, together with our applicable TRS, exercised our right to purchase and acquired 34.0% of the then outstanding AlerisLife common shares from ABP Trust at the Tender Offer Price for a total purchase price of $15,459, including transaction related costs, and we, our applicable TRS, ABP Trust and AlerisLife entered into a stockholders agreement.

In connection with AlerisLife's sale of its Ageility branded business to a subsidiary of Fox Rehabilitation on June 17, 2024, we approved Five Star's sublease to a subsidiary of Fox Rehabilitation of space at certain of our senior living communities, which is used to provide certain outpatient rehabilitation and wellness services.

On February 14, 2025 and July 15, 2025, AlerisLife paid aggregate cash dividends of $50,000 and $10,000, respectively, to its stockholders and our pro rata share of these cash dividends was $17,000 and $3,400, respectively.

In connection with the wind-down of its business, on January 9, 2026 AlerisLife paid an aggregate cash dividend of $80,000 to its stockholders. Our pro rata share of this cash dividend was $27,200. See Note 6 for further information regarding our relationships, agreements and transactions with AlerisLife (including Five Star) and Note 2 for further information regarding our investment in AlerisLife.

Our Manager, RMR. We have two agreements with RMR to provide management services to us: (1) a business management agreement, which relates to our business generally; and (2) a property management agreement, which relates to the property level operations of many of our properties, including our medical office and life science properties, and major renovation or repositioning activities at our senior living communities that we may request RMR to manage from time to time. See Note 7 for further information regarding our management agreements with RMR.

Our Joint Ventures. In connection with our entering into the LSMD JV in January 2022, we paid mortgage escrow amounts and closing costs that were payable by that joint venture. The remaining costs totaled $3,965 as of December 31, 2025 and are included in other assets, net, in our consolidated balance sheet. RMR provides management services to each of the Seaport JV and the LSMD JV. See Note 7 for further information regarding those management agreements with RMR.

Leases with RMR. We lease office space to RMR in certain of our properties for RMR's property management offices. We recognized rental income from RMR for leased office space of $423, $460 and $196 for the years ended December 31, 2025, 2024 and 2023, respectively. Our office space leases with RMR are terminable by RMR if our management agreements with RMR are terminated.

Share Awards to RMR Employees. As described in Note 5, we award shares to our officers and other employees of RMR annually. Generally, one fifth of these awards vest on the award date and one fifth vests on each of the next four anniversaries of the award dates. In certain instances, we may accelerate the vesting of an award, such as in connection with the award holder's retirement as an officer of us or an officer or employee of RMR. These awards to RMR employees are in addition to the share awards to our Managing Trustees, as Trustee compensation, and the fees we paid to RMR. See Note 5 for

information regarding our share awards and activity as well as certain share purchases we made in connection with share award recipients satisfying tax withholding obligation on vesting share awards.