Reed played under Rex Ryan as a member of the Jets in 2013.
“Ed Reed is going to be such a great asset to our team,” head coach Rex Ryan said in a statement. “Obviously he's played in this system and been an MVP caliber guy in this system. He's going to be such a great asset for players. He's a real student of the game as well and he's going to be a phenomenal coach.”
Coach Donnie Henderson will not return for a fourth year with the Bills as Ryan adjusts his coaching staff following an 8–8 season.
Ryan has brought on his twin brother Rob to become the team's assistant head coach responsible for defense.
Reed holds the NFL record for most career playoff interceptions (9), most career interception return yards (1,590) and the longest interception return for a touchdown (108) as he spent 11 seasons of his 13-year career with the Baltimore Ravens.
Reed played under Ryan as a member of the Jets in 2013.
He was also a nine-time Pro Bowl selection to go along with his 2004 NFL Defensive Player of the Year award. He was a member of the Super Bowl XLVII-winning Ravens in 2012.
Reed announced his retirement in May 2014 after signing a one-day contract to retire as a Raven.
- Christopher Chavez