The Jets signed Jefferson on Thursday, Ethan Greenberg of the team's official site reports.
Jefferson is now in line to join New York in 2023, where he'll ultimately pursue his eighth NFL campaign. As a member of the Seahawks this past season, the 291-pounder appeared in all 17 games and tallied 29 tackles and a career-high 5.5 sacks in that span. He'll likely compete for a starting gig throughout the offseason with Solomon Thomas, given Quinnen Williams has a firm grasp on the Jets' other starting defensive tackle spot.