Colvin was cut almost immediately after Houston's Monday night loss to the New Orleans Saints, during which he allowed two touchdown passes and a key conversion on New Orleans game-winning drive.
The Texans signed Colvin to a four-year, $34 million contract last season and will still pay Colvin $7.5 million in guaranteed money.
In Washington, Colvin will join a defensive backfield starring Josh Norman, Quinton Dunbar and Fabian Moreau at cornerback. Dunbar and Moreau, however, are entering Washington's Week 2 clash with the Dallas Cowboys with knee and ankle injuries, respectively. Dunbar is questionable, while Moreau is doubtful to play against Dallas.
Colvin could be playing significant snaps for Washington as early as this Sunday.