Office Properties Income Trust

We are a real estate investment trust, or REIT, formed in 2009 under Maryland law. As of December 31, 2025, our wholly owned properties were comprised of 122 properties containing approximately 17.1 million rentable square feet (all square footage amounts included within this Annual Report on Form 10-K are unaudited) and we had a noncontrolling ownership interest of 51% in an unconsolidated joint venture that owned two properties containing approximately 0.3 million rentable square feet. As of December 31, 2025, our properties have an undepreciated carrying value of approximately $3.7 billion and a depreciated carrying value of approximately $2.9 billion. As of December 31, 2025, our properties were leased to 212 different tenants, with a weighted average remaining lease term (based on annualized rental income as defined below) of approximately 6.6 years. The U.S. government is our largest tenant, representing approximately 17.2% of our annualized rental income as of December 31, 2025. The term annualized rental income as used herein is defined as the annualized contractual base rents from our tenants pursuant to our lease agreements as of December 31, 2025, plus straight line rent adjustments and estimated recurring expense reimbursements to be paid to us, and excluding lease value amortization. Our principal executive offices are located at Two Newton Place, 255 Washington Street, Suite 300, Newton, Massachusetts 02458-1634, and our telephone number is (617) 219-1440.