COPT Announces Format Change to Its 2020 Annual Meeting of Shareholders

Corporate Office Properties Trust ("COPT" or the "Company") (NYSE: OFC) announces that, its 2020 Annual Meeting of Shareholders (the "Annual Meeting") will be held as a virtual-only meeting via live audio webcast on its previously announced date of May 21, 2020 at 9:30 a.m. Eastern Time. The Company made this decision to provide certainty of executing the Annual Meeting during the high level of uncertainty caused by the COVID-19 pandemic.

Shareholders of record as of the close of business on March 12, 2020 are still encouraged to vote their shares in advance of the Annual Meeting through one of the below methods which were described in the proxy materials previously distributed. To vote prior to the meeting, shareholders must take one of the following actions prior to 11:59 p.m. Eastern Time on May 20, 2020:

• Sign, date and promptly mail the proxy card or voting instruction form received, or
• Vote via the Internet (at www.proxyvote.com), or
• By telephone (at 1-800-690-6903)

If you are a shareholder of record (i.e., you hold your shares through the Company's transfer agent, EQ Shareowner Services), to participate in the virtual Annual Meeting follow the instructions below:

• Between 10 and 15 minutes before the 9:30 a.m. Eastern Time start on May 21^st, visit: https://web.lumiagm.com/230674981
• Click on ?I have a control number' and enter the first 13 digits of that control number listed on the notice or proxy card received
• Enter Meeting Code: COPT2020 (case sensitive)
• Follow the instructions on the website to cast a vote

If you hold your shares through an intermediary (i.e., a bank, broker, or other nominee), to participate in the virtual Annual Meeting, you will need to follow the instructions below:

• Contact your bank, broker, or other nominee.
• Shareholders wanting to vote at the meeting, will need to request a legal proxy from their bank, broker, or other nominee. In order to ensure that their bank, broker, or other nominee will be able to provide the legal proxy in a timely fashion, shareholders are advised to submit the request to their bank, broker, or other nominee no later than 5:00 p.m. Eastern Time on May 7, 2020.
• Shareholders will need a new control number in order to register for and attend the virtual Annual Meeting. Once a new control number has been obtained, to participate in the Annual Meeting, please follow the steps set forth above for shareholders of record.
• Shareholders will be required to provide their legal proxy when voting during the virtual Annual Meeting. The website for the meeting will provide the necessary information on how to submit the legal proxy.

Additional information regarding the ability of shareholders to ask questions during the Annual Meeting, related rules of conduct and other materials for the Annual Meeting will be available at:
https://web.lumiagm.com/230674981

Technical support will be available beginning at 9:00 a.m. Eastern Time on May 21, 2020 through the conclusion of the Annual Meeting by contacting EQ Shareowner Services at 1-800-468-9716.

A replay of the Annual Meeting will be posted when available in the ?Annual Meeting & Proxy Materials' section of COPT's Investors website: https://investors.copt.com/

Definitive Additional Proxy Materials are being filed with the Securities and Exchange Commission and are being made available to shareholders on or about April 21, 2020.

Except as specifically revised by the information contained herein, this Press Release does not revise or update any of the other information set forth in the Proxy Statement. The Press Release does not alter in any manner either the record date for the Annual Meeting or the date and time of the Annual Meeting of Shareholders. This Press Release should be read in conjunction with the Proxy Statement. From and after the date of this Press Release, any references to the "Proxy Statement" are to the proxy statement as supplemented by the materials filed with the SEC.

About COPT

COPT is a REIT that owns, manages, leases, develops and selectively acquires office and data center properties. The majority of its portfolio is in locations that support the United States Government and its contractors, most of whom are engaged in national security, defense and information technology ("IT") related activities servicing what it believes are growing, durable, priority missions ("Defense/IT Locations"). The Company also owns a portfolio of office properties located in select urban/urban-like submarkets in the Greater Washington, DC/Baltimore region with durable Class-A office fundamentals and characteristics ("Regional Office Properties"). As of December 31, 2019, the Company derived 88% of its core portfolio annualized rental revenue from Defense/IT Locations and 12% from its Regional Office Properties. As of the same date and including 15 buildings owned through unconsolidated joint ventures, COPT's core portfolio of 168 office and data center shell properties encompassed 19.0 million square feet and was 94.6% leased; the Company also owned one wholesale data center with a critical load of 19.25 megawatts that was 76.9% leased.

Forward-Looking Information

This press release may contain "forward-looking" statements, as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, that are based on the Company's current expectations, estimates and projections about future events and financial trends affecting the Company. Forward-looking statements can be identified by the use of words such as "may," "will," "should," "could," "believe," "anticipate," "expect," "estimate," "plan" or other comparable terminology. Forward-looking statements are inherently subject to risks and uncertainties, many of which the Company cannot predict with accuracy and some of which the Company might not even anticipate. Although the Company believes that the expectations, estimates and projections reflected in such forward-looking statements are based on reasonable assumptions at the time made, the Company can give no assurance that these expectations, estimates and projections will be achieved. Future events and actual results may differ materially from those discussed in the forward-looking statements and the Company undertakes no obligation to update or supplement any forward-looking statements.

The areas of risk that may affect these expectations, estimates and projections include, but are not limited to, those risks described in Item 1A of the Company's Annual Report on Form 10-K for the year ended December 31, 2019, as well as risks associated with uncertainties regarding the impact of the COVID-19 pandemic on the Company's business and national, regional and local economic conditions.