BRANDYWINE OPERATING PARTNERSHIP, L.P.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

OR

For the transition period from to

Brandywine Realty Trust

Brandywine Operating Partnership, L.P.

(Exact name of registrant as specified in its charter)

2929 Arch Street

Suite 1800

Philadelphia, PA 19104

(Address of principal executive offices) (Zip Code)

(610)325-5600

(Registrant’s telephone number, including area code)

Securities registered pursuant to section 12(b) of the Act:

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

Brandywine Realty Trust:

Brandywine Operating Partnership, L.P.:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b)

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

As of June 30, 2025, the aggregate market value of the Common Shares of Beneficial Interest held by non-affiliates of Brandywine Realty Trust was $710,790,280 based upon the last reported sale price of $4.29 per share on the New York Stock Exchange on June 30, 2025. An aggregate of 173,711,848 Common Shares of Beneficial Interest was outstanding as of February 18, 2026.

As of June 30, 2025, the aggregate market value of the 515,595 common units of limited partnership (“Units”) held by non-affiliates of Brandywine Operating Partnership, L.P. was $2,211,903 based upon the last reported sale price of $4.29 per share on the New York Stock Exchange on June 30, 2025 of the Common Shares of Beneficial Interest of Brandywine Realty Trust, the sole general partner of Brandywine Operating Partnership, L.P. (For this computation, the Registrant has excluded the market value of all Units beneficially owned by Brandywine Realty Trust.)

Documents Incorporated By Reference

Portions of the proxy statement for the 2025 Annual Meeting of Shareholders of Brandywine Realty Trust are incorporated by reference into Part III of this Form 10-K.

EXPLANATORY NOTE

This report combines the annual reports on Form 10-K for the year ended December 31, 2025 of Brandywine Realty Trust (the “Parent Company”) and Brandywine Operating Partnership, L.P. (the “Operating Partnership”). The Parent Company is a Maryland real estate investment trust, or REIT, that owns its assets and conducts its operations through the Operating Partnership, a Delaware limited partnership, and subsidiaries of the Operating Partnership. The Parent Company, the Operating Partnership and their consolidated subsidiaries are collectively referred to in this report as the “Company.” In addition, terms such as “we”, “us”, or “our” used in this report may refer to the Company, the Parent Company, or the Operating Partnership.

The Parent Company is the sole general partner of the Operating Partnership and as of December 31, 2025, owned a 99.7% interest in the Operating Partnership. The remaining 0.3% interest consists of common units of limited partnership interest issued by the Operating Partnership to third parties in exchange for contributions of properties to the Operating Partnership. As the sole general partner of the Operating Partnership, the Parent Company has full and complete authority over the Operating Partnership’s day-to-day operations and management.

As general partner with control of the Operating Partnership, the Parent Company consolidates the Operating Partnership for financial reporting purposes, and the Parent Company does not have significant assets other than its investment in the Operating Partnership. Therefore, the assets and liabilities of the Parent Company and the Operating Partnership are the same in their respective financial statements. The separate discussions of the Parent Company and the Operating Partnership in this report should be read in conjunction with each other to understand the results of the Company’s operations on a consolidated basis and how management operates the Company.

Management operates the Parent Company and the Operating Partnership as one enterprise. The management of the Parent Company consists of the same members as the management of the Operating Partnership. These members are officers of both the Parent Company and of the Operating Partnership.

The Company believes that combining the annual reports on Form 10-K of the Parent Company and the Operating Partnership into a single report will:

•facilitate a better understanding by the investors of the Parent Company and the Operating Partnership by enabling them to view the business as a whole in the same manner as management views and operates the business;

•remove duplicative disclosures and provide a more straightforward presentation in light of the fact that a substantial portion of the disclosure applies to both the Parent Company and the Operating Partnership; and

•create time and cost efficiencies through the preparation of one combined report instead of two separate reports.

There are few differences between the Parent Company and the Operating Partnership, which are reflected in the footnote disclosures in this report. The Company believes it is important to understand the differences between the Parent Company and the Operating Partnership in the context of how these entities operate as an interrelated consolidated company. The Parent Company is a REIT, whose only material asset is its ownership of the partnership interests of the Operating Partnership. As a result, the Parent Company does not conduct business itself, other than acting as the sole general partner of the Operating Partnership, issuing equity from time to time (and contributing the net proceeds of such issuances to the Operating Partnership) and guaranteeing the debt obligations of the Operating Partnership. The Operating Partnership holds substantially all the assets of the Company, including the Company's ownership interests in the real estate ventures described below. The Operating Partnership conducts the operations of the Company’s business and is structured as a partnership with no publicly traded equity. Except for net proceeds from equity issuances by the Parent Company, which are contributed to the Operating Partnership in exchange for partnership units, the Operating Partnership generates the capital required by the Company’s business through the Operating Partnership’s operations, by the Operating Partnership’s incurrence of indebtedness (directly and through subsidiaries) and through the issuance of partnership units of the Operating Partnership or equity interests in subsidiaries of the Operating Partnership.

The equity and noncontrolling interests in the Parent Company and the Operating Partnership’s equity are the main areas of difference between the consolidated financial statements of the Parent Company and the Operating Partnership. The common units of limited partnership interest in the Operating Partnership are accounted for as partners’ equity in the Operating Partnership’s financial statements while the common units of limited partnership interests held by parties other than the Parent Company are presented as noncontrolling interests in the Parent Company’s financial statements. The differences between the Parent Company and the Operating Partnership’s equity relate to the differences in the equity issued at the Parent Company and Operating Partnership levels.

To help investors understand the differences between the Parent Company and the Operating Partnership, this report presents the following as separate notes or sections for each of the Parent Company and the Operating Partnership:

•Consolidated Financial Statements;

•Parent Company’s and Operating Partnership’s Equity

This report also includes separate Item 9A. (Controls and Procedures) disclosures and separate Exhibit 31 and 32 certifications for each of the Parent Company and the Operating Partnership in order to establish that the Chief Executive Officer and the Chief Financial Officer of each entity have made the requisite certifications and that the Parent Company and Operating Partnership are compliant with Rule 13a-15 or Rule 15d-15 of the Securities Exchange Act of 1934, as amended, and 18 U.S.C. § 1350.

In order to highlight the differences between the Parent Company and the Operating Partnership, the separate sections in this report for the Parent Company and the Operating Partnership specifically refer to the Parent Company and the Operating Partnership. In the sections that combine disclosures of the Parent Company and the Operating Partnership, this report refers to such disclosures as those of the Company. Although the Operating Partnership is generally the entity that directly or indirectly enters into contracts and real estate ventures and holds assets and debt, reference to the Company is appropriate because the business is one enterprise and the Parent Company operates the business through the Operating Partnership.

TABLE OF CONTENTS

Filing Format

This combined Annual Report on Form 10-K is being filed separately by Brandywine Realty Trust (the “Parent Company”) and Brandywine Operating Partnership, L.P. (the “Operating Partnership”).

Forward-Looking Statements

The Private Securities Litigation Reform Act of 1995 (the “1995 Act”) provides a “safe harbor” for forward-looking statements. This report and other materials filed by us with the Securities and Exchange Commission (the “SEC”) (as well as information included in oral or other written statements made by us) contain statements that are forward-looking, including statements relating to business and real estate development activities, acquisitions, dispositions, future capital expenditures, financing sources, governmental regulation (including environmental regulation) and competition. We intend such forward-looking statements to be covered by the safe-harbor provisions of the 1995 Act. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “will,” “should” and similar expressions, as they relate to us, are intended to identify forward-looking statements. Although we believe that the expectations reflected in such forward-looking statements are based on reasonable assumptions, we can give no assurance that our expectations will be achieved. These forward-looking statements are inherently uncertain, and actual results may differ from expectations. Our actual future results and trends may differ materially from expectations depending on a variety of factors discussed in our filings with the SEC. These factors include without limitation:

•adverse changes in national and local economic conditions, the real estate industry and the commercial real estate markets in which we operate, which would have a negative effect on, among other things:

•overall market occupancy levels and demand for office and other commercial space and rental rates;

•the financial condition of our tenants, many of which are financial, legal and other professional firms, our lenders, counterparties to our derivative financial instruments and institutions that hold our cash balances and short-term investments, which may expose us to increased risks of default by these parties;

•the availability of financing on attractive terms or at all, which may adversely impact our future interest expense and our ability to pursue acquisition and development opportunities and refinance existing debt; and

•real estate asset valuations, a decline in which may limit our ability to dispose of assets at attractive prices or obtain or maintain debt financing secured by our properties or on an unsecured basis and may result in additional impairments of our real estate;

•competition from other owners, developers and investors, including for tenants and investment opportunities;

•our failure to lease unoccupied space in accordance with our projections, including on account of changing work patterns and reduced demand for our real estate;

•our failure to re-lease occupied space upon expiration of leases, including on account of changing work patterns and reduced demand for office space;

•tenant defaults and the bankruptcy of major tenants;

•volatility in capital and credit markets, including changes that reduce availability, and increase costs, of capital;

•increasing interest rates, which would increase our borrowing costs and could adversely affect the market price of our securities;

•failure to obtain financing at budgeted levels for developments and redevelopments;

•failure of interest rate hedging contracts to perform as expected and the effectiveness of such arrangements;

•inflation, which, among other things, has increased our operating expenses and costs for supplies and labor;

•failure of acquisitions, developments and other investments, including projects undertaken through joint ventures and equity investments in third parties, to perform as expected;

•unanticipated costs associated with the purchase, integration and operation of our acquisitions;

•unanticipated costs and delays to complete, lease-up and operate our developments and redevelopments, including on account of shortages of, and delays in shipping of, supplies and materials for our developments and redevelopments;

•additional impairment charges;

•unanticipated costs, and cost overruns associated with land development, including building and construction moratoriums and inability to obtain necessary zoning, land-use, building, occupancy and other required governmental approvals, construction cost increases or overruns and construction delays;

•lack of liquidity of real estate investments, which could make it difficult for us to respond to changing economic or financial conditions or changes in the operating performance of our properties;

•potential damage from natural disasters, including hurricanes and other weather-related events, which could result in substantial costs to us;

•the impact of epidemics, pandemics, or other outbreaks of illness, disease or virus and the action taken by government authorities and others related thereto, including actions that restrict or limit the ability of our Company, our properties and our tenants to operate;

•uninsured losses due to insurance deductibles, self-insurance retention, uninsured claims or casualties, or losses in excess of applicable coverage;

•increased costs for, or lack of availability of, adequate insurance, including for terrorist acts or environmental liabilities;

•actual or threatened terrorist attacks or other acts or threats of violence and threats to public safety;

•impacts from changes to U.S. trade and foreign relations policies, including the imposition of tariffs;

•the impact of geopolitical conflicts;

•the impact of a U.S. government shutdown;

•security breaches through cyber attacks, cyber intrusions or otherwise, as well as other significant disruptions of our information technology (IT) networks and related systems, which support our operations and our properties;

•the impact on workplace and tenant space demands driven by technology, employee culture and commuting patterns;

•demand for tenant services beyond those traditionally provided by landlords;

•liability and clean-up costs incurred under environmental or other laws;

•risks associated with our investments in real estate ventures and unconsolidated entities, including our lack of sole decision-making authority and our reliance on our venture partners’ financial condition;

•inability of real estate venture partners to fund venture obligations or perform under our real estate venture development agreements;

•failure to manage our growth effectively into new product types within our portfolio and real estate venture arrangements;

•failure of dispositions to close in a timely manner;

•the impact of climate change and compliance costs relating to laws and regulations governing climate change;

•risks associated with federal, state and local tax audits;

•complex regulations relating to our status as a real estate investment trust, or REIT, and the adverse consequences of our failure to qualify as a REIT;

•changes in accounting principles, or their application or interpretation, and our ability to make estimates and the assumptions underlying the estimates, which could have an effect on our earnings; and

•our internal control over financial reporting may not be considered effective which could result in a loss of investor confidence in our financial reports, and in turn could have an adverse effect on the market price of our securities.

Given these uncertainties, and the other risks identified in the “Risk Factors” section and elsewhere in this report, we caution readers not to place undue reliance on forward-looking statements. We assume no obligation to update or supplement forward-looking statements as a result of subsequent events, new information, changed circumstances, or otherwise, except as required by law.