Cofield, 30, spent the past four seasons with the Redskins.
In Washington, Cofield amassed 100 tackles and nine sacks. He missed eight games with an ankle injury last season, and recorded only seven tackles and a sack.
Before joining the Redskins on a six-year, $36 million deal in 2011, Cofield spent five seasons with the New York Giants.
According to NFL.com, the move will save Washington about $4.12 million in cap room.
On Thursday, a report said the Redskins have signed defensive tackle Ricky Jean Francois to a three-year deal.
- Jeremy Woo