COPT DEFENSE PROPERTIES

Notes to Consolidated Financial Statements

1. Organization

COPT Defense Properties (“COPT Defense”) and subsidiaries (collectively, the “Company,” “we,” or “us”) is a fully-integrated and self-managed real estate investment trust (“REIT”) focused on owning, operating, and developing properties in locations proximate to, or sometimes containing, key U.S. Government (“USG”) defense installations and missions (which we refer to herein as our Defense/IT Portfolio). Our tenants include the USG and its defense contractors, who are primarily engaged in priority national security activities, and who generally require mission-critical and high security property enhancements. Our property portfolio is predominantly comprised of office properties and single-tenant data center shells. As of March 31, 2026, our Defense/IT Portfolio included:

•201 operating properties totaling 23.2 million square feet. We owned 24 of these properties totaling 4.3 million square feet through unconsolidated real estate joint ventures;

•seven properties under development that will total approximately 1.0 million square feet upon completion; and

•approximately 980 acres of land controlled that we believe could be developed into approximately 10.8 million square feet.

We also ownedsix other operating properties totaling 2.0 million square feet and approximately 50 acres of other developable land in the Greater Washington, DC/Baltimore region as of March 31, 2026.

We conduct almost all of our operations and own almost all of our assets through our operating partnership, COPT Defense Properties, L.P. (“CDPLP”) and subsidiaries (collectively, the “Operating Partnership”), of which COPT Defense is the sole general partner. CDPLP owns real estate directly and through subsidiary partnerships and limited liability companies (“LLCs”). In addition to owning real estate, CDPLP also owns subsidiaries that provide real estate services such as property management, development, and construction services primarily for our properties but also for third parties, most of which are tenants. Some of these services are performed by a taxable REIT subsidiary (“TRS”).

Equity interests in CDPLP are in the form of common and preferred units. As of March 31, 2026, COPT Defense owned 97.2% of the outstanding CDPLP common units (“common units”) and there wereno preferred units outstanding. Common units not owned by COPT Defense carry certain redemption rights. The number of common units owned by COPT Defense is equivalent to the number of outstanding common shares of beneficial interest (“common shares”) of COPT Defense, and the entitlement of common units to quarterly distributions and payments in liquidation is substantially the same as that of COPT Defense common shareholders.

COPT Defense’s common shares are publicly traded on the New York Stock Exchange (“NYSE”) under the ticker symbol “CDP”.

2. Summary of Significant Accounting Policies

Basis of Presentation

These consolidated financial statements include the accounts of COPT Defense, the Operating Partnership, their subsidiaries and other entities in which COPT Defense has a majority voting interest and control. We also consolidate certain entities when control of such entities can be achieved through means other than voting rights (“variable interest entities” or “VIEs”) if we are deemed to be the primary beneficiary of such entities. We eliminate all intercompany balances and transactions in consolidation.

We use the equity method of accounting when we own an interest in an entity and can exert significant influence over but cannot control the entity’s operations. We discontinue equity method accounting if our investment in an entity (and net advances) is reduced to zero unless we have guaranteed obligations of the entity or are otherwise committed to provide further financial support for the entity.

When we own an equity investment in an entity and cannot exert significant influence over its operations, we measure the investment at fair value, with changes recognized through net income. For an investment without a readily determinable fair value, we measure the investment at cost, less any impairments, plus or minus changes resulting from observable price changes for an identical or similar investment of the same issuer.

These interim financial statements should be read together with the consolidated financial statements and notes thereto as of and for the year ended December 31, 2025 included in our 2025 Annual Report on Form 10-K. The unaudited consolidated financial statements include all adjustments that are necessary, in the opinion of management, to fairly state our financial position and results of operations. All adjustments are of a normal recurring nature. The consolidated financial statements have been prepared using the accounting policies described in our 2025 Annual Report on Form 10-K.

Recent Accounting Pronouncements

In November 2024, the Financial Accounting Standards Board (“FASB”) issued guidance requiring disaggregated disclosure of specified information about certain expense categories included in expense line items on the consolidated statements of operations in the notes to the financial statements. This guidance is effective for us for annual periods beginning after December 15, 2026 and interim periods beginning after December 15, 2027. Early adoption is permitted. We expect to apply this guidance prospectively to financial statements issued for reporting periods after the effective date. We are currently assessing the application of this guidance on our future consolidated financial statements.

In November 2025, the FASB amended existing hedge accounting guidance to more closely align with the economics of an entity’s risk management activities by increasingly enabling entities to achieve and maintain hedge accounting for highly-effective economic hedges of forecasted transactions. This guidance is effective for us for interim and annual periods beginning after December 15, 2026. Early adoption is permitted. We expect to apply this guidance prospectively to financial statements issued for reporting periods after our adoption of the guidance. We are currently assessing the application of this guidance on our future consolidated financial statements.

Effective January 1, 2026, we adopted guidance issued by the FASB that provides a practical expedient for use in estimating expected credit losses on non-lease revenue related accounts receivable and contract assets. The practical expedient permits an entity to assume that current conditions as of the balance sheet date do not change for the remaining life of the asset. This guidance was applied prospectively and did not affect our consolidated financial statements.

3. Fair Value Measurements

Recurring Fair Value Measurements

The fair values of our interest rate derivatives, as disclosed in Note 9, are determined using widely accepted valuation techniques, including a discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate market data and implied volatilities in such interest rates. While we determined that the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our interest rate derivatives utilize Level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default. However, as of March 31, 2026, we assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivatives and determined that these adjustments were not significant. As a result, we determined that our interest rate derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.

The carrying values of cash and cash equivalents, restricted cash, accounts receivable, other assets (excluding investing receivables), and accounts payable and accrued expenses are reasonable estimates of their fair values because of the short maturities of these instruments. The fair values of our investing receivables, as disclosed in Note 7, were based on the discounted estimated future cash flows of the loans (categorized within Level 3 of the fair value hierarchy); the discount rates used approximate current market rates for loans with similar maturities and credit quality, and the estimated cash payments include scheduled principal and interest payments. For our disclosure of debt fair values in Note 8, we estimated the fair value of our unsecured senior notes based on quoted market rates for our senior notes (categorized within Level 1 of the fair value hierarchy) and estimated the fair value of our other debt based on the discounted estimated future cash payments to be made on such debt (categorized within Level 3 of the fair value hierarchy); the discount rates used approximate current market rates for loans, or groups of loans, with similar maturities and credit quality, and the estimated future payments include scheduled principal and interest payments. Fair value estimates are made as of a specific point in time, are subjective in nature and involve uncertainties and matters of significant judgment.

The table below presents our financial assets and liabilities accounted for at fair value on a recurring basis as of March 31, 2026 and the hierarchy level of inputs used in measuring their respective fair values under applicable accounting standards (in thousands):

(1)Included in the line entitled “prepaid expenses and other assets, net” on our consolidated balance sheet.

4. Properties, Net

Operating properties, net consisted of the following (in thousands):

5. Leases

Lessor Arrangements

We lease real estate properties, comprised primarily of office properties and data center shells, to third parties. These leases encompass all, or a portion, of properties, with various expiration dates. Our lease revenue is comprised of: fixed-lease revenue, including contractual rent billings under leases recognized on a straight-line basis over lease terms and amortization of lease incentives and above- and below-market lease intangibles; and variable-lease revenue, including tenant expense recoveries, lease termination revenue, and other revenue from tenants that is not fixed under leases. The table below presents our composition of lease revenue recognized between fixed- and variable-lease revenue (in thousands):

Lessee Arrangements

As of March 31, 2026, our consolidated balance sheet included $54.6 million in right-of-use assets associated primarily with land leased from third parties underlying certain properties that we are operating with various expiration dates. Our property right-of-use assets and property lease liabilities on our consolidated balance sheets consisted of the following (in thousands):

As of March 31, 2026, our operating leases had a weighted average remaining lease term of 42 years and a weighted average discount rate of 7.4%, while our finance leases had a weighted average remaining lease term ofsix years and a weighted average discount rate of 8.1%. The table below presents our total property lease cost (in thousands):

The table below presents the effect of property lease payments on our consolidated statements of cash flows (in thousands):

Payments on property leases were due as follows (in thousands):

(1)Represents the nine months ending December 31, 2026.

6. Real Estate Joint Ventures

Consolidated Real Estate Joint Ventures

The table below presents information pertaining to our investments in consolidated real estate joint ventures, which are each variable interest entities (dollars in thousands):

(1)We fund all capital requirements. Our partner receives distributions of $1.2 million of annual operating cash flows, plus certain fees for leasing and development, and we receive the remainder.

Unconsolidated Real Estate Joint Ventures

The table below presents information pertaining to our investments in unconsolidated real estate joint ventures accounted for using the equity method of accounting (dollars in thousands):

(1)Included $35.8 million and $36.4 million reported in “investment in unconsolidated real estate joint ventures” and $24.0 million and $22.8 million for investments with deficit balances reported in “other liabilities” on our consolidated balance sheets as of March 31, 2026 and December 31, 2025, respectively. Investments with deficit balances are attributable to JV distributions of nonrecourse debt refinancing proceeds in excess of our equity in B RE COPT DC JV III LLC and B RE COPT DC JV II LLC; we are obligated to fund our share of future cash flow requirements, if any, of these joint ventures.

(2)Our investment in B RE COPT DC JV II LLC was lower than our share of the joint venture’s equity by $6.4 million as of March 31, 2026 and $6.5 million as of December 31, 2025 due to a difference between our cost basis and our share of the joint venture’s underlying equity in its net assets. We recognize adjustments to our share of the joint venture’s earnings and losses resulting from this basis difference in the underlying assets of the joint venture.

7. Investing Receivables

Investing receivables consisted of the following (in thousands):

The balances above included accrued interest receivable, net of allowance for credit losses, of $673,000 as of March 31, 2026 and $3.8 million as of December 31, 2025.

Our notes receivable from the City of Huntsville funded infrastructure costs in connection with our LW Redstone Company, LLC joint venture (see Note 6) and carry an interest rate of 9.95%. Our other investing loan receivable as of March 31, 2026 carries an effective interest rate of 12.0% and matures in 2026.

The fair value of these receivables was approximately $73 million as of March 31, 2026 and December 31, 2025.

8. Debt, Net

Our debt consisted of the following (dollars in thousands):

(1)The carrying values of our debt other than the Revolving Development Facility and Revolving Credit Facility reflect net deferred financing costs of $3.8 million as of March 31, 2026 and $4.1 million as of December 31, 2025.

(2)Including the effect of an interest rate swap that hedges the risk of interest rate changes, the weighted average interest rate on our variable-rate secured debt as of March 31, 2026 was 3.1%; excluding the effect of this swap, the weighted average interest rate on this debt as of March 31, 2026 was 5.2%.

(3)The weighted average interest rate on the Revolving Development Facility was 5.0% as of March 31, 2026.

(4)The facility matures in October 2029, with the ability to extend such maturity by a 12-month period at our option, provided that there is no default under the facility and we pay an extension fee of 0.250% of the total amount available under the facility.

(5)The weighted average interest rate on the Revolving Credit Facility was 4.5% as of March 31, 2026.

(6)The facility matures in October 2029, with the ability for us to extend such maturity bytwo six-month periods at our option, provided that there is no default under the facility and we pay an extension fee of 0.0625% of the total availability under the facility for each extension period.

(7)The interest rate on this loan was 4.7% as of March 31, 2026.

(8)This facility matures in January 2027, with the ability for us to extend such maturity by a 12-month period at our option, provided that there is no default under the facility and we pay an extension fee of 0.125% of the outstanding term loans under the facility.

(9)These notes have an exchange settlement feature under which the notes may, under certain circumstances, be exchangeable at the option of the holders. Upon exchange, the principal amount of notes is payable in cash, with the remainder of the exchange obligation, if any, as determined based on the exchange price per common share at the time of settlement, payable in cash, common shares, or a combination thereof at our election. As of March 31, 2026, the exchange rate of the notes equaled 33.5584 of our common shares per $1,000 principal amount of notes (equivalent to an exchange price of approximately $29.80 per common share).

(10)The carrying value of these notes reflects unamortized commissions totaling $4.5 million as of March 31, 2026 and $4.9 million as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 5.8%.

(11)The carrying value of these notes reflects unamortized discounts and commissions totaling $1.0 million as of March 31, 2026 and $1.1 million as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 2.1%.

(12)The carrying value of these notes reflects unamortized discounts and commissions totaling $4.1 million as of March 31, 2026 and $4.3 million as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 4.8%.

(13)The carrying value of these notes reflects unamortized discounts and commissions totaling $5.4 million as of March 31, 2026 and $5.7 million as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 2.9%.

(14)The carrying value of these notes reflects unamortized discounts and commissions totaling $3.1 million as of March 31, 2026 and $3.2 million as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 3.0%.

(15)The carrying value of these notes reflects unamortized discounts and commissions totaling $153,000 as of December 31, 2025. The effective interest rate under the notes, including amortization of such costs, was 2.5%. Refer to paragraph below for further disclosure.

(16)This note carries an interest rate that, upon assumption, was below market rates and it therefore was recorded at its fair value based on applicable effective interest rates. The carrying value of this note reflects an unamortized discount totaling $1,000 as of December 31, 2025.

All debt is owed by the Operating Partnership. While COPT Defense is not directly obligated by any debt, it has guaranteed CDPLP’s Revolving Development Facility, Revolving Credit Facility, term loan facility, and Unsecured Senior Notes. As of March 31, 2026, all of our mortgage and other secured debt was for consolidated real estate joint ventures (see Note 6), except for our Revolving Development Facility.

On March 16, 2026, we repaid at maturity our $400.0 million in 2.25% Senior Notes due 2026 (the “2.25% Notes”).

The table below presents interest expense recognized on the 5.25% Exchangeable Senior Notes due 2028 (the “5.25% Notes”) (in thousands):

Certain of our debt instruments require that we comply with a number of restrictive financial covenants. As of March 31, 2026, we were compliant with these financial covenants.

Our debt matures on the following schedule (in thousands):

(1)Represents the nine months ending December 31, 2026.

(2)Represents scheduled principal amortization and maturities only and therefore excludes net discounts and deferred financing costs of $21.9 million.

We capitalized interest costs of $1.8 million in the three months ended March 31, 2026 and $927,000 in the three months ended March 31, 2025.

The table below presents information pertaining to the fair value of our debt (in thousands):

9. Interest Rate Derivatives

The table below presents the key terms and fair values of our interest rate swap derivatives (dollars in thousands):

(1)The notional amount of this instrument is scheduled to amortize to $10.0 million.

Each of these swaps was designated as a cash flow hedge of interest rate risk.

The table below presents the fair value of our interest rate derivatives as well as their classification on our consolidated balance sheets (in thousands):

The table below presents the effect of our interest rate derivatives on our consolidated statements of operations and comprehensive income (in thousands):

Based on the fair value of our derivatives as of March 31, 2026, we estimate that approximately $70,000 of net gains will be reclassified from accumulated other comprehensive income (“AOCI”) as a decrease to interest expense over the next 12 months.

Our agreements with interest rate derivative counterparties contain provisions under which, if we default or are capable of being declared in default on defined levels of our indebtedness, we could also be declared in default on our derivative obligations. Failure to comply with the loan covenant provisions could result in our being declared in default on any derivative instrument obligations covered by the agreements. As of March 31, 2026, we were not in default with any of these provisions. As of March 31, 2026, we did not have any derivatives in liability positions.

10. Redeemable Noncontrolling Interest

Redeemable noncontrolling interest on our consolidated balance sheets included the ownership interest of our partner in LW Redstone Company, LLC due to the partner’s rights to require us to acquire their interest. The table below presents the activity for redeemable noncontrolling interest (in thousands):

We determine the fair value of the interest based on unobservable inputs after considering the assumptions that market participants would make in pricing the interest. We apply a discount rate to the estimated future cash flows allocable to our partner from the properties underlying the respective joint venture. Estimated cash flows used in such analyses are based on our plans for the properties and our views of market and economic conditions, and consider items such as current and future rental rates, occupancy projections, and estimated operating and development expenditures.

11. Equity

As of March 31, 2026, we had remaining capacity under our at-the-market stock offering program equal to an aggregate gross sales price of $300 million in common shares.

We declared dividends per common share of $0.32 in the three months ended March 31, 2026 and $0.305 in the three months ended March 31, 2025.

See Note 15 for disclosure of common share activity pertaining to our share-based compensation plans.

12. Information by Business Segment

We havetwo reportable segments: Defense/IT Portfolio; and Other. We also report on Defense/IT Portfolio sub-segments, which include the following: Fort George G. Meade and the Baltimore/Washington Corridor (“Fort Meade/BW Corridor”); Redstone Arsenal (in Huntsville, Alabama); Northern Virginia Defense/IT Locations (“NoVA Defense/IT”); Lackland Air Force Base (in San Antonio, Texas); locations serving the U.S. Navy (“Navy Support”), which included properties proximate to the Washington Navy Yard in Washington, DC, the Naval Air Station Patuxent River in Maryland, and the Naval Surface Warfare Center Dahlgren Division in Virginia; and data center shells (properties leased to tenants to be operated as data centers in which the tenants fund the costs for the power, fiber connectivity, and data center infrastructure).

We measure the performance of our segments through the measure we define as net operating income from real estate operations (“NOI from real estate operations”), which includes real estate revenues and other segment items, which is comprised of: property operating expenses; and the net of revenues and property operating expenses of real estate operations owned through unconsolidated real estate joint ventures (“UJV” or “UJVs”) that is allocable to our ownership interest (“UJV NOI allocable to COPT Defense”). Property operating expenses represent costs associated with operating our properties, including property taxes, ground rents, utilities, property management, insurance, repairs, and exterior and interior maintenance, as well as associated labor and indirect costs.

Our chief operating decision maker uses budget to actual comparisons of operating expense information on a consolidated basis and for our Same Property pool (defined as our properties stably owned and 100% operational throughout both the current and prior year) to manage expenses associated with operating our properties.

Amounts reported for segment assets represent long-lived assets associated with consolidated operating properties (including the carrying value of properties, right-of-use assets, net of related lease liabilities, intangible assets, deferred leasing costs, deferred rents receivable, and lease incentives) and the carrying value of investments in UJVs owning operating properties included in our data center shells sub-segment (totaling $11.8 million and $35.1 million as of March 31, 2026 and 2025, respectively), which is net of deficit investment balances in UJVs reported in “other liabilities” on our consolidated balance sheets.

Amounts reported as additions to long-lived assets represent additions to existing consolidated operating properties, excluding transfers from non-operating properties, which we report separately.

The table below presents segment financial information for our reportable segments (in thousands):

The table below reconciles our segment revenues to total revenues as reported on our consolidated statements of operations (in thousands):

The table below reconciles UJV NOI allocable to COPT Defense to equity in income of unconsolidated entities as reported on our consolidated statements of operations (in thousands):

As previously discussed, we provide real estate services such as property management, development, and construction services primarily for our properties but also for third parties. The primary manner in which we evaluate the operating performance of our service activities is through a measure we define as net operating income from service operations (“NOI from service operations”), which is based on the net of revenues and expenses from these activities. Construction contract and other service revenues and expenses consist primarily of subcontracted costs that are reimbursed to us by the customer along with a management fee. The operating margins from these activities are small relative to the revenue. We believe NOI from service operations is a useful measure in assessing both our level of activity and our profitability in conducting such operations. The table below presents the computation of our NOI from service operations (in thousands):

The table below reconciles our NOI from real estate operations for reportable segments and NOI from service operations to net income as reported on our consolidated statements of operations (in thousands):

The table below reconciles our segment assets to our consolidated total assets (in thousands):

The accounting policies of the segments are the same as those used to prepare our consolidated financial statements. In the segment reporting presented above, we did not allocate interest expense, depreciation and amortization, gain on sales of real estate, and equity in income of unconsolidated entities not included in NOI to our real estate segments since they are not included in the measure of segment profit reviewed by management. We also did not allocate general, administrative, leasing and other expenses, interest and other income, net, income taxes, and noncontrolling interests because these items represent general corporate or non-operating property items not attributable to segments.

13. Construction Contract and Other Service Revenues

We disaggregate in the table below our construction contract and other service revenues by compensation arrangement as we believe it best depicts the nature, timing, and uncertainty of our revenue (in thousands):

We recognized an insignificant amount of revenue in the three months ended March 31, 2026 and 2025 from performance obligations satisfied (or partially satisfied) in previous periods.

Accounts receivable related to our construction contract services is included in accounts receivable, net on our consolidated balance sheets. The beginning and ending balances of accounts receivable related to our construction contracts were as follows (in thousands):

Contract assets are included in prepaid expenses and other assets, net on our consolidated balance sheets. The beginning and ending balances of our contract assets were as follows (in thousands):

Contract liabilities are included in other liabilities on our consolidated balance sheets. Changes in contract liabilities were as follows (in thousands):

Revenue allocated to the remaining performance obligations under existing contracts as of March 31, 2026 that will be recognized as revenue in future periods was $34.5 million, of which we expect to recognize approximately $30 million in thenine months ending December 31, 2026, and the remainder in 2027.

We haveno deferred incremental costs incurred to obtain or fulfill our construction contracts or other service revenues as of March 31, 2026 and December 31, 2025. Credit loss expense or recoveries on construction contracts receivable and unbilled construction revenue were insignificant for the three months ended March 31, 2026 and 2025.

14. Credit Losses on Financial Assets and Other Instruments

The table below presents the activity for our allowance for credit losses for the three months ended March 31, 2026 and 2025 (in thousands):

(1)Included in the line entitled “accounts receivable, net” on our consolidated balance sheets.

(2)The balances as of March 31, 2026 and December 31, 2025 included insignificant amounts in the lines entitled “accounts receivable, net” and “prepaid expenses and other assets, net” on our consolidated balance sheets.

(3)Included in the line entitled “interest and other income, net” on our consolidated statements of operations.

The table below presents the amortized cost basis of our investing receivables, tenant notes receivable, and sales-type lease receivables by credit risk classification, by origination year as of March 31, 2026 (in thousands):

Our investment grade credit risk classification represents entities with investment grade credit ratings from ratings agencies (such as S&P Global Ratings, Moody’s Investors Service, Inc., or Fitch Ratings, Inc.), meaning that they are considered to have at least an adequate capacity to meet their financial commitments, with credit risk ranging from minimal to moderate. Our non-investment grade credit risk classification represents entities with either no credit agency credit ratings or ratings deemed to be sub-investment grade; we believe that there is significantly more credit risk associated with this classification. The credit risk classifications of our investing receivables and tenant notes receivable were last updated in March 2026.

None of the investing and tenant notes receivables set forth above were past due, which we define as being delinquent by more than three months from the due date, as of March 31, 2026.

We did not have any tenant notes receivable on nonaccrual status as of March 31, 2026 and December 31, 2025. We did not recognize any interest income on tenant notes receivable on nonaccrual status during the three months ended March 31, 2026 and 2025.

15. Share-Based Compensation

Restricted Shares

The table below presents restricted shares activity under our share-based compensation plan for the three months ended March 31, 2026:

Restricted shares granted to employees generally vest based on increments and over periods of time set forth under the terms of the respective awards provided that the employee remains employed by us. Restricted shares granted to non-employee Trustees vest on the first anniversary of the grant date, provided that the Trustee remains in the position.

The aggregate intrinsic value of restricted shares that vested was $4.4 million for the three months ended March 31, 2026.

Profit Interest Units in CDPLP (“PIUs”)

We grantedtwo forms of PIUs: time-based PIUs (“TB-PIUs”); and performance-based PIUs (“PB-PIUs”). TB-PIUs are subject to forfeiture restrictions until the end of the requisite service period, at which time the TB-PIUs automatically convert into vested PIUs. PB-PIUs are subject to a market condition in that the number of earned awards are determined at the end of the performance period (as described further below) and then settled in vested PIUs. Vested PIUs automatically convert into common units in CDPLP if, or when, a book-up event (as defined under federal income tax regulations) has occurred and carry substantially the same rights to distributions as common units.

TB-PIUs

The table below presents TB-PIUs activity under our share-based compensation plan for the three months ended March 31, 2026:

TB-PIUs granted to senior management team members vest based on increments and over periods of time set forth under the terms of the respective awards provided that the employee remains employed by us. TB-PIUs granted to non-employee Trustees vest on the first anniversary of the grant date, provided that the Trustee remains in the position. Prior to vesting, TB-PIUs carry substantially the same rights to distributions as common units but carry no redemption rights.

The aggregate intrinsic value of TB-PIUs that vested was $3.1 million for the three months ended March 31, 2026.

Performance-Based Awards

On January 1, 2026, we granted certain senior management team members performance-based equity, in the form of either PB-PIUs or performance share units (“PSUs”) as based on the election of the grant recipients. The grant recipients elected to receive, in aggregate,324,870 PB-PIUs (equal to 200% of the target award) and 4,496 PSUs (equal to 200% of the target award). The performance-based equity awards have athree-year performance period concluding on the earlier of December 31, 2028 or the date of: (1) termination by us without cause, death, or disability of the employee, or constructive discharge of the employee (collectively, “qualified termination”); or (2) a sale event.

The number of earned awards following the end of the performance period will be determined based on the percentile rank of COPT Defense’s total shareholder return (“TSR”) relative to a peer group of companies, as presented in the following schedule:

If the percentile rank exceeds the 25th percentile and is betweentwo of the percentile ranks set forth in the table above, then the percentage of the earned awards will be interpolated between the ranges set forth in the table above to reflect any performance between the listed percentiles. If COPT Defense’s TSR is negative when its TSR’s percentile rank exceeds the 50th percentile, then the earned award payout percentage used to arrive at the earned awards would be reduced by 25 percentage points, but in no event to a payout percentage of less than 100% of the target award; however, the resulting reduction in earned awards would subsequently be deemed earned awards if COPT Defense’s TSR becomes positive on any date in the calendar year following the end of the performance period. In addition, regardless of COPT Defense’s TSR relative to the peer group, no less than 100% of the target award will be earned if COPT Defense’s TSR is at least 10% and no less than 50% of the target award will be earned if COPT Defense’s TSR is at least 6%, with linear interpolation if COPT Defense’s TSR is between 6% and 10%.

During the performance period, PB-PIUs carry rights to distributions equal to 10% of the distribution rights of common units, while PSUs do not carry such rights. Performance-based awards do not carry redemption or voting rights.

Following the end of the performance period, we will settle the awards as follows:

•for PB-PIUs, issuing vested PIUs equal to: the number of earned awards; and the excess, if any, of (1) the aggregate distributions that would have been paid with respect to vested PIUs issued in settlement of the earned awards through the date of settlement had such vested PIUs been issued on the grant date over (2) the aggregate distributions made on the PB-PIUs through the date of settlement, divided by the price of our common shares over a defined period of time; and

•for PSUs, issuing fully-vested COPT Defense shares equal to: the number of earned awards; and the aggregate dividends that would have been paid with respect to the common shares issued in settlement of the earned awards through the date of settlement had such shares been issued on the grant date, divided by the price of our common shares over a defined period of time.

If a performance period ends due to a sale event or qualified termination, the number of earned awards is prorated based on the portion of thethree-year performance period that has elapsed. If employment is terminated by the employee or by us for cause, all unvested performance-based awards are forfeited.

The performance-based awards granted on January 1, 2026 had an aggregate grant date fair value of $6.4 million ($39.10 per target-level award) in the form of PB-PIUs and $89,000 ($39.52 per target-level award) in the form of PSUs, which are being recognized over the performance period. The grant date fair values were computed using Monte Carlo models that included the following assumptions: baseline common share value of $27.80; expected volatility for common shares of 23.4%; and a risk-free interest rate of 3.7%.

For PB-PIUs granted to executives on January 1, 2023 that vested on December 31, 2025, COPT Defense’s TSR ranking relative to the peer group companies equated to an earned award payout of 200% of the target award, which resulted in our issuance of 250,070 vested PIUs in settlement of the PB-PIUs on February 5, 2026.

16. Earnings Per Share (“EPS”)

We present both basic and diluted EPS. We compute basic EPS by dividing net income available to common shareholders allocable to unrestricted common shares by the weighted average number of unrestricted common shares outstanding during the period after allocating undistributed earnings between common shareholders and participating securities under the two-class method. Our participating securities include restricted shares and PIUs and deferred share awards not previously settled by common share issuances. Our computation of diluted EPS is similar except that:

•the denominator is increased to include: (1) the weighted average number of potential additional common shares that would have been outstanding if securities that are convertible into common shares were converted; and (2) the effect of dilutive potential common shares outstanding during the period attributable to a redeemable noncontrolling interest in a joint venture and share-based compensation awards using the if-converted or treasury stock methods; and

•the numerator is adjusted to add back any changes in income that would result from the assumed conversion into common shares that we add to the denominator.

We compute diluted EPS using the treasury stock method for unvested restricted shares, TB-PIUs, and deferred share awards and the if-converted method for exchangeable debt (including our 5.25% Notes), common units, redeemable noncontrolling interest, PB-PIUs, PSUs, and vested PIUs and deferred share awards not previously settled by common share issuances.

Summaries of the numerator and denominator for purposes of basic and diluted EPS calculations are presented below (in thousands, except per share data):

Our diluted EPS computations do not include the effects of the following securities since the conversions of such securities would increase diluted EPS for the respective periods (in thousands):

The following securities were also excluded from the computation of diluted EPS because their effect was antidilutive:

•weighted average restricted shares and deferred share awards of 520,000 and 471,000 for the three months ended March 31, 2026 and 2025, respectively; and

•weighted average TB-PIUs of 228,000 for the three months ended March 31, 2026 and 2025.

Our 5.25% Notes issued in 2023 have an exchange settlement feature under which the principal amount of notes exchanged is payable in cash, with the remainder of the exchange obligation, if any, determined based on the exchange price per common share at the time of settlement, payable in cash, common shares, or a combination thereof at our election. This feature of the 5.25% Notes affects our diluted EPS calculation for periods in which the weighted average closing price of our common shares is higher than the exchange price applicable to such periods, which resulted in an additional 472,000 shares in the denominator for diluted EPS for the three months ended March 31, 2026.

17. Commitments and Contingencies

Litigation and Claims

In the normal course of business, we are subject to legal actions and other claims. We record losses for specific legal proceedings and claims when we determine that a loss is probable and the amount of loss can be reasonably estimated. As of March 31, 2026, management believes that it is reasonably possible that we could recognize a loss of up to $5.4 million for certain municipal tax claims; while we do not believe this loss would materially affect our financial position or liquidity, it could be material to our results of operations. Management believes that it is also reasonably possible that we could incur losses pursuant to other claims but do not believe such losses would materially affect our financial position, liquidity, or results of operations. Our assessment of the potential outcomes of these matters involves significant judgment and is subject to change based on future developments.

Environmental

We are subject to various federal, state and local environmental regulations related to our property ownership and operations. We have performed environmental assessments of our properties, the results of which have not revealed any environmental liability that we believe would have a materially adverse effect on our financial position, operations, or liquidity.

In connection with a lease and subsequent sale in prior periods ofthree properties in Dayton, New Jersey, we agreed to provide certain environmental indemnifications limited to $19 million in the aggregate. We have insurance coverage in place to mitigate most of any potential future losses that may result from these indemnification agreements.

Tax Incremental Financing Obligation

Anne Arundel County, Maryland issued tax incremental financing bonds to third-party investors in order to finance public improvements needed in connection with our project known as the National Business Park. These bonds had a remaining principal balance of approximately $23 million as of March 31, 2026. The real estate taxes on increases in assessed values post-bond issuance of properties in development districts encompassing the National Business Park are transferred to a special fund pledged to the repayment of the bonds. While we are obligated to fund, through a special tax, any future shortfalls between debt service of the bonds and real estate taxes available to repay the bonds, as of March 31, 2026, we do not expect any such future fundings will be required.

18. Subsequent Event

On April 23, 2026, we acquired approximately 17 acres of land (to be included in our NoVA Defense/IT sub-segment) for a purchase price of approximately $43 million, subject to a ground lease underlyingtwo fully-leased operating properties located at 15020 and 15030 Conference Center Drive in Chantilly, Virginia.