Organization	9 Months Ended
Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization The RMR Group Inc., or RMR Inc., is a holding company and substantially all of its business is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC. RMR Inc. is a Maryland corporation and RMR LLC is a Maryland limited liability company. RMR Inc. serves as the sole managing member of RMR LLC and, in that capacity, operates and controls the business and affairs of RMR LLC. In these condensed consolidated financial statements, unless otherwise indicated, “we”, “us” and “our” refer to RMR Inc. and its direct and indirect subsidiaries, including RMR LLC. As of June 30, 2026, RMR Inc. owned 16,092,402 class A membership units of RMR LLC, or Class A Units, and 1,000,000 class B membership units of RMR LLC, or Class B Units. The aggregate RMR LLC membership units RMR Inc. owns represented 53.3% of the economic interest of RMR LLC as of June 30, 2026. We refer to economic interest as the right of a holder of a Class A Unit or Class B Unit to share in distributions made by RMR LLC and, upon liquidation, dissolution or winding up of RMR LLC, to share in the assets of RMR LLC after payments to creditors. A wholly owned subsidiary of ABP Trust, a Maryland statutory trust, owns 15,000,000 redeemable Class A Units, representing 46.7% of the economic interest of RMR LLC as of June 30, 2026, which is presented as noncontrolling interest in The RMR Group LLC within the condensed consolidated financial statements. Adam Portnoy, Chair of our Board, one of our Managing Directors and our President and Chief Executive Officer, is the sole trustee, an officer and the controlling shareholder of our controlling shareholder, ABP Trust, and owns all of ABP Trust’s voting securities. RMR LLC provides management services to four publicly traded equity real estate investment trusts, or REITs: Diversified Healthcare Trust, or DHC, which owns senior living communities, medical office and life science properties and other healthcare related properties; Industrial Logistics Properties Trust, or ILPT, which owns and leases industrial and logistics properties; Office Properties Income Trust, or OPI, which owns and leases office properties primarily to single tenants and those with high credit quality characteristics; and Service Properties Trust, or SVC, which owns a diverse portfolio of service-focused retail net lease properties and hotels. DHC, ILPT, OPI and SVC are collectively referred to as the Managed Equity REITs. RMR LLC’s wholly owned subsidiary, Tremont Realty Capital LLC, or Tremont, an investment adviser registered with the Securities and Exchange Commission, or SEC, provides advisory services for Seven Hills Realty Trust, or SEVN. SEVN is a publicly traded mortgage REIT that focuses on originating and investing in first mortgage loans secured by middle market and transitional commercial real estate. RMR LLC provides management services to Sonesta International Hotels Corporation, or Sonesta, a privately owned franchisor and operator of hotels, resorts and cruise ships in the United States, Canada, Latin America, the Caribbean and the Middle East, and the majority of the U.S. hotels that Sonesta operates are owned by SVC. RMR LLC also provides management services to AlerisLife Inc., or AlerisLife, which operated senior living communities, many of which were owned by DHC. In September 2025, AlerisLife announced that it had entered into agreements to transition the management of its senior living communities to third party operators and in January 2026 completed the sale of all of its assets. AlerisLife will continue to wind down its business and operations. RMR LLC will continue to provide management services through the wind down period. RMR LLC provides management services through certain of its subsidiaries to multiple private funds, joint ventures and the underlying residential real estate assets of the funds, as well as property management services to third party owners. The residential real estate we manage through these subsidiaries are presented as RMR Residential in these condensed consolidated financial statements. In addition, RMR LLC provides management services to other private capital vehicles, including ABP Trust and other private entities that own commercial real estate, of which certain of our Managed Equity REITs may own minority equity interests. These other private clients, along with Sonesta, AlerisLife and clients of RMR Residential are collectively referred to as the Private Capital clients.

The RMR Group Inc., or RMR Inc., is a holding company and substantially all of its business is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC. RMR Inc. is a Maryland corporation and RMR LLC is a Maryland limited liability company. RMR Inc. serves as the sole managing member of RMR LLC and, in that capacity, operates and controls the business and affairs of RMR LLC. In these condensed consolidated financial statements, unless otherwise indicated, “we”, “us” and “our” refer to RMR Inc. and its direct and indirect subsidiaries, including RMR LLC.

As of June 30, 2026, RMR Inc. owned 16,092,402 class A membership units of RMR LLC, or Class A Units, and 1,000,000 class B membership units of RMR LLC, or Class B Units. The aggregate RMR LLC membership units RMR Inc. owns represented 53.3% of the economic interest of RMR LLC as of June 30, 2026. We refer to economic interest as the right of a holder of a Class A Unit or Class B Unit to share in distributions made by RMR LLC and, upon liquidation, dissolution or winding up of RMR LLC, to share in the assets of RMR LLC after payments to creditors. A wholly owned subsidiary of ABP Trust, a Maryland statutory trust, owns 15,000,000 redeemable Class A Units, representing 46.7% of the economic interest of RMR LLC as of June 30, 2026, which is presented as noncontrolling interest in The RMR Group LLC within the condensed consolidated financial statements. Adam Portnoy, Chair of our Board, one of our Managing Directors and our President and Chief Executive Officer, is the sole trustee, an officer and the controlling shareholder of our controlling shareholder, ABP Trust, and owns all of ABP Trust’s voting securities.

RMR LLC provides management services to four publicly traded equity real estate investment trusts, or REITs: Diversified Healthcare Trust, or DHC, which owns senior living communities, medical office and life science properties and other healthcare related properties; Industrial Logistics Properties Trust, or ILPT, which owns and leases industrial and logistics properties; Office Properties Income Trust, or OPI, which owns and leases office properties primarily to single tenants and those with high credit quality characteristics; and Service Properties Trust, or SVC, which owns a diverse portfolio of service-focused retail net lease properties and hotels. DHC, ILPT, OPI and SVC are collectively referred to as the Managed Equity REITs.

RMR LLC’s wholly owned subsidiary, Tremont Realty Capital LLC, or Tremont, an investment adviser registered with the Securities and Exchange Commission, or SEC, provides advisory services for Seven Hills Realty Trust, or SEVN. SEVN is a publicly traded mortgage REIT that focuses on originating and investing in first mortgage loans secured by middle market and transitional commercial real estate.

RMR LLC provides management services to Sonesta International Hotels Corporation, or Sonesta, a privately owned franchisor and operator of hotels, resorts and cruise ships in the United States, Canada, Latin America, the Caribbean and the Middle East, and the majority of the U.S. hotels that Sonesta operates are owned by SVC.

RMR LLC also provides management services to AlerisLife Inc., or AlerisLife, which operated senior living communities, many of which were owned by DHC. In September 2025, AlerisLife announced that it had entered into agreements to transition the management of its senior living communities to third party operators and in January 2026 completed the sale of all of its assets. AlerisLife will continue to wind down its business and operations. RMR LLC will continue to provide management services through the wind down period.

RMR LLC provides management services through certain of its subsidiaries to multiple private funds, joint ventures and the underlying residential real estate assets of the funds, as well as property management services to third party owners. The residential real estate we manage through these subsidiaries are presented as RMR Residential in these condensed consolidated financial statements.

In addition, RMR LLC provides management services to other private capital vehicles, including ABP Trust and other private entities that own commercial real estate, of which certain of our Managed Equity REITs may own minority equity interests. These other private clients, along with Sonesta, AlerisLife and clients of RMR Residential are collectively referred to as the Private Capital clients.