"It's something we're very thrilled about, getting Adam signed for the next four years and potentially two more after that," general manager John Mozeliak said. "He embodies everything we look for in a player -- his talent, his personality."
The Cardinals renewed Wainwright's contract at $448,000 earlier this month, while continuing to negotiate on a long-term deal. The right-hander is the likely Opening Day starter, although the team has not made an announcement.
"I feel like I'm playing in the best place possible," Wainwright said. "I love the city, and my wife loves the city, and we're going to be there for hopefully a long, long time and a long time after this contract also.
"It's just a great situation for both parties, I think."
The 26-year-old Wainwright went 14-12 with a 3.70 ERA in his first year in the rotation after serving as the closer in the 2006 World Series. His win total is the best in franchise history for a first-year starter, and his 2.71 ERA after the All-Star break was third-best in the National League.
The deal is heavily backloaded. It includes a $750,000 signing bonus with salaries of $500,000 this year, $2.6 million in 2009, $4.65 million in 2010 and 6.5 million in 2011. There are club options at $9 million in 2012 and $12 million in 2013.
Wainwright has a 2.08 ERA in three March appearances.