<!DOCTYPE html>
<html>
    <head>
        <title>COPT Defense Properties Quarterly report pursuant to Section 13 or 15(d)</title>
        <link href="https://ir.stockpr.com/copt/stylesheets/ir.stockpr.css" rel="stylesheet" type="text/css">
        <script src="https://ir.stockpr.com/javascripts/ir.js"></script>
        <link rel="stylesheet" type="text/css" href="https://ir.stockpr.com/stylesheets/xbrl.css">
        <script src="https://d1io3yog0oux5.cloudfront.net/_79e6f066a8b72759f6031aaea0843126/copt/files/theme/js/aside/ir/_js/all.js"></script>
    </head>
    <body>
        <div class="xbrl-content">
            <h3>Quarterly report pursuant to Section 13 or 15(d)</h3>
            <div id="xbrl-menu-top">
                <div class="navigation">
                    <ul class="xbrl-sf-menu">
                        
                            <li>
                                <a class="menu-item " href="/financial-information/sec-filings/xbrl_doc_only/474">Cover</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/474">Document and Entity Information</a></li>
                                                                    </ul>
                            </li>
                                                    <li>
                                <a class="menu-item " href="/financial-information/sec-filings/xbrl_doc_only/475">Financial Statements</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/475">Consolidated Balance Sheets</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/476">Consolidated Balance Sheets (Parenthetical)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/477">Consolidated Balance Sheets (Parenthetical 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/478">Consolidated Statements of Operations</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/479">Consolidated Statements of Comprehensive Income</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/480">Consolidated Statements of Equity</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/481">Consolidated Statements of Equity (Parenthetical)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/482">Consolidated Statements of Cash Flows</a></li>
                                                                    </ul>
                            </li>
                                                    <li>
                                <a class="menu-item " href="/financial-information/sec-filings/xbrl_doc_only/483">Notes to Financial Statements</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/483">Organization</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/484">Summary of Significant Accounting Policies</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/485">Fair Value Measurements</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/486">Properties, net</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/487">Real Estate Joint Ventures</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/488">Mortgage and Other Investing Receivables</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/489">Prepaid Expenses and Other Assets</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/490">Debt</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/491">Interest Rate Derivatives</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/492">Redeemable Noncontrolling Interest</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/493">Equity</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/494">Information by Business Segment</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/495">Share-Based Compensation</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/496">Income Taxes</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/497">Discontinued Operations</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/498">Earnings Per Share (&quot;EPS&quot;) and Earnings Per Unit (&quot;EPU&quot;)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/499">Commitments and Contingencies</a></li>
                                                                    </ul>
                            </li>
                                                    <li>
                                <a class="menu-item " href="/financial-information/sec-filings/xbrl_doc_only/500">Accounting Policies</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/500">Summary of Significant Accounting Policies (Policies)</a></li>
                                                                    </ul>
                            </li>
                                                    <li>
                                <a class="menu-item " href="/financial-information/sec-filings/xbrl_doc_only/501">Notes Tables</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/501">Fair Value Measurements (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/502">Properties, net (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/503">Real Estate Joint Ventures (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/504">Mortgage and Other Investing Receivables (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/505">Prepaid Expenses and Other Assets (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/506">Debt (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/507">Interest Rate Derivatives (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/508">Redeemable Noncontrolling Interest (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/509">Information by Business Segment (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/510">Share-Based Compensation (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/511">Income Taxes (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/512">Discontinued Operations (Tables)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/513">Earnings Per Share (&quot;EPS&quot;) and Earnings Per Unit (&quot;EPU&quot;) (Tables)</a></li>
                                                                    </ul>
                            </li>
                                                    <li>
                                <a class="menu-item current" href="/financial-information/sec-filings/xbrl_doc_only/514">Notes Details</a>
                                <ul class="submenu">
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/514">Organization (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/515">Organization (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/516">Fair Value Measurements (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/517">Fair Value Measurements (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/518">Fair Value Measurements (Details 3)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/519">Properties, net (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/520">Properties, net (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/521">Properties, net (Details 3)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/522">Real Estate Joint Ventures (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/523">Mortgage and Other Investing Receivables (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/524">Prepaid Expenses and Other Assets (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/525">Debt (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/526">Debt (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/527">Interest Rate Derivatives (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/528">Redeemable Noncontrolling Interests (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/529">Equity (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/530">Information by Business Segment (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/531">Information by Business Segment (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/532">Information by Business Segment (Details 3)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/533">Share-Based Compensation (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/534">Income Taxes (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/535">Discontinued Operations (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/536">Earnings Per Share (&quot;EPS&quot;) and Earnings Per Unit (&quot;EPU&quot;) (Details)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/537">Earnings Per Share (&quot;EPS&quot;) (Details 2)</a></li>
                                                                            <li><a href="/financial-information/sec-filings/xbrl_doc_only/538">Commitments and Contingencies (Details)</a></li>
                                                                    </ul>
                            </li>
                                            </ul>
                </div>
            </div>
            <div class="spr-xbrl-document">
                <h4>Commitments and Contingencies (Details)</h4>
                                <div style="clear:both;"></div>
            </div>
        </div>
    </body>
</html>