Kerrigan, 32, was a first-round pick by Washington in 2011 and played the first 10 years of his NFL career for Washington, racking up 95.5 sacks and 147 quarterback hits.
He started just one game in 2020 and played 38% of the team’s defensive snaps — by far the lowest of his career — but still had 5.5 sacks and five tackles for loss.
Kerrigan has 13.5 career sacks against Philadelphia, tied (Dallas Cowboys) for his most sacks against any one team.
“I know I probably wasn’t your favorite player over the past decade, but Eagles fans I’m fired up to be playing for you guys now! LFG!!!” Kerrigan wrote on social media.
Kerrigan joins a defensive end rotation in Philadelphia that includes Brandon Graham, Derek Barnett and Josh Sweat. He’ll be playing for new defensive coordinator Jonathan Gannon, who is expected to ask his linemen to read and react more, in contrast to former DC Jim Schwartz’s constant attack style.
Washington had left the door open for a possible return, according to a team source. But it also has starting ends Montez Sweat and Chase Young, and it drafted two more in William Bradley-King and Shaka Toney.
Washington also has two other young ends in James Smith-Williams, a 2020 seventh-round pick, and Casey Toohill. The team wanted to see how its young ends had developed before exploring a legitimate reunion with Kerrigan.
In January, Kerrigan told ESPN, “I always envisioned playing my entire career here.”
But he said by season’s end — and as a pending free agent — he had grown used to the thought of playing elsewhere. He remained confident in his ability.
ESPN’s John Keim contributed to this report.