The Buffalo Bills are searching for a coach after Doug Marrone's surprise decision to step down after the team's best finish in a decade.
Bills owner Terry Pegula announced Wednesday that Marrone exercised the opt-out clause in his contract.
"We are disappointed that Coach Marrone will no longer be an important part of our organization," Pegula said in a team statement. "We thank him for all of his hard work and leadership during his tenure, and wish him and his family the best with the next chapter in their lives."
Pegula said the team will immediately begin searching for a coach. One candidate might already be on the staff in defensive coordinator Jim Schwartz, who previously spent five seasons coaching the Detroit Lions.
Marrone's decision to step down was a stunning one, coming after he led the Bills to a 9-7 finish in his second season in Buffalo. It was the Bills' first winning season in 10 years.
Buffalo, however, missed the playoffs to extend the NFL's longest active postseason drought to 15 seasons.
The opt-out clause in Marrone's contract went into effect after Pegula and wife Kim bought the team in October. Marrone had until Wednesday to make his decision.
The team was sold after Hall of Fame owner Ralph Wilson died in March.
Marrone went 15-17 in Buffalo. He was hired after four seasons at Syracuse, where Marrone helped revive his alma mater's struggling program.
The decision to step down came two weeks after Marrone told reporters he wasn't going anywhere after the Bills were eliminated from playoff contention following a 26-24 loss at Oakland.
Marrone isn't the first Bills coach to step down while still under contract.
Mike Mularkey quit the team for undisclosed reasons following the 2005 season after Tom Donahoe was fired as president and general manager.
Marrone was supposed to be part of a new era in Buffalo that began with Russ Brandon being elevated to president and CEO on Jan. 1, 2013.
Brandon hired Marrone. That spring, Doug Whaley was promoted to general manager after Buddy Nix stepped down.
The Bills are searching for their seventh head coach since Wade Phillips was fired following the 2000 season.