Investor Presentaiton

OFFICE PROPERTIES INCOME TRUST NON-GAAP FINANCIAL MEASURES AND CERTAIN DEFINITIONS Annualized dividend yield is the annualized dividend per common share paid during the period divided by the closing price of OPI's common shares at the end of the period. Annualized rental income is calculated using the annualized contractual base rents from OPI's tenants pursuant to its lease agreements as of September 30, 2023, plus straight line rent adjustments and estimated recurring expense reimbursements to be paid to OPI, and excluding lease value amortization. Cap Rate represents the ratio of (x) annual straight line rental income, excluding the impact of above and below market lease amortization, based on existing leases at the acquisition date, less estimated annual property operating expenses as of the date of the acquisition, excluding depreciation and amortization expense, to (y) the acquisition purchase price. GAAP is U.S. generally accepted accounting principles. Gross book value of real estate assets is real estate properties at cost, plus certain acquisition costs, if any, before depreciation and purchase price allocations, less impairment write downs, if any. Gross sales price is equal to the gross contract price and excludes closing costs. Investment grade tenants include: (a) investment grade rated tenants; (b) tenants with investment grade rated parent entities that guarantee the tenant's lease obligations; and/or (c) tenants with investment grade rated parent entities that do not guarantee the tenant's lease obligations. Tenants contributing 53.6% of annualized rental income as of September 30, 2023 were investment grade rated (or their payment obligations were guaranteed by an investment grade rated parent) and tenants contributing an additional 10.4% of annualized rental income as of September 30, 2023 were subsidiaries of an investment grade rated parent (although these parent entities are not liable for the payment of rents). Leased square feet is pursuant to leases existing as of September 30, 2023, and includes (i) space being fitted out for tenant occupancy pursuant to OPI's lease agreements, if any, and (ii) space which is leased, but is not occupied or is being offered for sublease by tenants, if any. Square footage measurements are subject to changes when space is remeasured or reconfigured for new tenants. MSA is metropolitan statistical area. Net debt is total debt less cash. Percent leased includes (i) space being fitted out for occupancy pursuant to our lease agreements, if any, and (ii) space which is leased, but is not occupied or is being offered for sublease by tenants, if any, as of the measurement date. Purchase price represents the gross purchase price, including assumed debt, if any, and excludes acquisition related costs and purchase price adjustments and allocations. Rolling four quarter CAD represents CAD for the preceding twelve month period as of the respective quarter end date. Same properties for the three months ended September 30, 2023 is based on properties OPI owned continuously since July 1, 2022; excludes properties classified as held for sale and properties undergoing significant redevelopment, if any, and three properties owned by two unconsolidated joint ventures in which OPI owns a 51% and 50% interest. Same properties for the nine months ended September 30, 2023 is based on properties OPI owned continuously since January 1, 2022; excludes properties classified as held for sale and properties undergoing significant redevelopment, if any, and three properties owned by two unconsolidated joint ventures in which OPI owns a 51% and 50% interest. Total debt represents the outstanding principal balance as of the date reported. Total gross assets is total assets plus accumulated depreciation. Weighted average remaining lease term is the average remaining lease term in years weighted based on annualized rental income. 24 24

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