Thurman had been with the Jets since 2008, including the last two seasons as defensive coordinator. He joins new Bills coach Rex Ryan's staff after Buffalo introduced Ryan, fired as head coach of the Jets in December, on Wednesday.
Earlier this week, the Bills announced defensive coordinator Jim Schwartz would not return. The Bills finished No. 4 in both points and yards allowed this season. Led by Mario Williams, Jerry Hughes and Marcell Dareus, the Bills led the NFL with 54.0 sacks as a team.
The Jets finished 4-12 last season, but the team's defense finished sixth in yards allowed.
Before becoming defensive coordinator, Thurman had been a defensive backs coach for the Jets, Baltimore Ravens, Arizona Cardinals and at the University of Southern California. He played for the Dallas Cowboys and Phoenix Cardinals from 1978 through 1986.
- Paul Palladino