Kerrigan bid farewell to Washington in an Instagram post Sunday night, a sign he was close to an agreement with a new team.
The four-time Pro Bowl pass-rusher ranks first in Washington history with 95.5 career sacks. Kerrigan was demoted to a part-time role in 2020 as Washington gave more snaps to up-and-comers Chase Young and Montez Sweat.
Kerrigan posted at least 11 sacks four times in five seasons between 2014 and 2018 but had just 5.5 in each of the last two campaigns.
In Philadelphia, the 32-year-old will supplement an edge group led by Brandon Graham and Derek Barnett. The Eagles tallied the third-most sacks in the NFL last year despite injuries galore along their defensive line. Kerrigan has been durable throughout his career, missing only four games - all in 2019 - due to injury.
The Pittsburgh Steelers and Cincinnati Bengals also showed interest in Kerrigan before he decided to stay in the NFC East, according to ESPN's Adam Schefter.