Wainwright, 37, debuted as a bullpen arm in 2005 before blossoming into a front-line starter for the bulk of his career. He's the longest-tenured pitcher on the Cardinals; catcher Yadier Molina is the only current player who's been with the team longer.
Originally drafted by the Atlanta Braves, Wainwright was traded to the Cardinals as a minor-leaguer as part of the deal that sent J.D. Drew to Atlanta.
Injuries and inconsistency have crept into Wainwright's game in recent seasons. Since 2016, he's posted a 4.77 ERA over 362 1/3 innings.
Still, the three-time All-Star has been a constant presence and owns a career mark of 148-85 with a 3.32 ERA. His lengthy tenure with the club has also earned him the second spot on the franchise strikeout list with 1,623. He trails Hall of Famer Bob Gibson, who punched out 3,117 opponents in 17 seasons with the Cardinals.
Financial terms were not disclosed.