EXHIBIT 22.1

List of Subsidiary Issuers of Guaranteed Securities

As of September 30, 2021, Corporate Office Properties Trust was the guarantor of the outstanding guaranteed debt securities of its subsidiaries, as listed below:

Debt Instrument			Issuer
5.000% Senior Notes due 2025			Corporate Office Properties, L.P.
2.250% Senior Notes due 2026			Corporate Office Properties, L.P.
2.000% Senior Notes due 2029			Corporate Office Properties, L.P.
2.750% Senior Notes due 2031			Corporate Office Properties, L.P.