Four players from their active roster - all pending free agents - were re-signed: running back Mike Gillislee, wide receiver Greg Salas, cornerback Mario Butler, and punter Colton Schmidt.
Seven players from their practice squad were signed to reserve/future contracts: tight ends Blake Annen and Jacob Maxwell, offensive linemen Cyril Richardson and Ronald Patrick, edge rusher Cedric Reed, and defensive backs Jonathan Dowling and Phillip Thomas.
Salas, who was signed late in the season and played in two games, was a pending unrestricted free agent. He caught three passes for 41 yards in the win over the Jets, and the 27-year-old has also played for Rex Ryan for two years with the Jets.
Gillislee, Butler, and Schmidt were all pending exclusive rights free agents, and their early re-signings indicate that they'll be players of significance as the 2016 roster begins to take shape next summer. Schmidt, the 25-year-old punter, just set a Bills franchise record with a 41.3-yard net punting average in 2015, so bringing him back was essential. Gillislee made a positive impression late in the season, and Butler made enough plays in the final two weeks to warrant another look, as well.
After the slew of re-signings, the Bills have seven unrestricted free agents, seven restricted free agents, and one exclusive rights free agent left on their list of 2016 free agents. You can view that full list here. They have also ensured that seven of their nine practice squad players will be back next summer, with the only two not (yet) tendered being quarterback Zac Dysert and tight end Manasseh Garner.