Bowens, who played at Michigan and Western Illinois in college, played in one game this season with the Redskins after being claimed off waivers from the Bills.
He had joined Buffalo in a trade with Green Bay for tight end Bobby Collins. He had 3.5 sacks for the Packers last season.
Bowens played his first NFL season with the Broncos, recording 10 tackles, one sack and nine special teams tackles. Denver sent him to Green Bay in February of 2000 in exchange for a seventh-round draft pick.
Bowens becomes the fifth defensive end on the roster, joining Kenny Mixon, Jason Taylor, Lorenzo Bromell and Adewale Ogunleye.