Terms weren't immediately known.
Searcy, 26, emerged as a full-time starter on a Bills defense that was among the league's best last season.
Searcy started 13 games last season, recording a career-high three interceptions while adding 65 tackles and a forced fumble.
The Bills drafted Searcy in the fourth round in 2011. After two seasons as a reserve, his role expanded in 2013, when he notched a career-high 71 tackles and 3.5 sacks in seven starts.
ESPN.com Bills reporter Mike Rodak contributed to this report.