St. Louis agreed to a one-year, $9 million deal with the catcher, a source told ESPN's Jesse Rogers, confirming multiple reports.
Molina is a rarity, having spent his entire career -- 2,025 games -- with the Cardinals. The only two players to play more games in a Cardinals uniform in franchise history are Hall of Famers Stan Musial (3,026) and Lou Brock (2,289).
Molina shared a video of his career highlight on Instagram on Monday and ended it with the words "I'm back."
The nine-time All-Star played 42 of 60 games during the pandemic-shortened season, hitting .262 with four home runs and 16 RBIs.
Molina also became the 12th catcher in major league history to join the 2,000-hit club, and his 2,001 hits currently rank fifth among all active players (and sixth in Cardinals franchise history). Behind the plate, Molina has been a steadying influence for the Cardinals' pitching staff while also being credited with 170 defensive runs saved as a catcher since 2004.
He has caught 1,989 games, the most with a single franchise in major league history and No. 6 all time among all catchers.
"I think about [the Hall of Fame]," Molina told ESPN before last season. "When I started my career, I had to overcome a lot of obstacles. ... All I've done is work hard to get better and better every single year to become the best catcher I can be. And my numbers are obviously there. I think that, because of the way I catch, that I'm one of the best catchers to have ever played in baseball."
Molina, 38, tested positive for COVID-19 in August as the Cardinals were hit by an outbreak just three games into the 2020 season.
He was critical of the statistical-based process -- without the usual input from managers or coaches -- used to determine the Gold Glove finalists in 2020. The nine-time winner, which ranks third among catchers, had hoped to tie Hall of Famer Johnny Bench for second with 10.
Molina has been a key component to the Cardinals' success over the years, having helped lead the team to four National League pennants and two World Series titles. He has a career .281 average with 160 home runs, 932 RBIs, 66 stolen bases and has caught 350 of the would-be 869 baserunners trying to steal a base (40% success rate).