David G. Harrison is admitted to practice in the following courts:
- Supreme Court of the United States
- United States Court of Appeals for the Federal Circuit
- United Sates Court of Appeals for the Fourth Circuit
- United States Court of International Trade
- United States District Court for the Western District of Virginia
- United States District Court for the Eastern District of Virginia
- United States District Court for the Eastern District of Tennessee
- Supreme Court of Virginia
- All trial courts in Virginia