EXHIBIT 22.1

List of Subsidiary Issuers of Guaranteed Securities

As of December 31, 2023, COPT Defense Properties was the guarantor of the outstanding guaranteed debt securities of its subsidiaries, as listed below:

Debt Instrument			Issuer
2.250% Senior Notes due 2026			COPT Defense Properties, L.P.
2.000% Senior Notes due 2029			COPT Defense Properties, L.P.
2.750% Senior Notes due 2031			COPT Defense Properties, L.P.
2.900% Senior Notes due 2033			COPT Defense Properties, L.P.