The two-time champion catcher will call the World Series this year and then retire from his analyst job at Fox.
"I wanted to step down while I know I can still do the job and proud of the job I've done," the 71-year-old McCarver said during a conference call Wednesday.
His health is good, McCarver said. So are his passion and energy for the game.
It was just time.
"It's not a tough call," he said. "It's not a sad thing for me."
McCarver had been thinking about moving on for a couple of years. This winter, Fox executives visited him at his home in Florida to discuss extending his contract, which expires after the 2013 season.
They never even started negotiations. McCarver had already made up his mind.
McCarver has seen other people in various businesses stay at their jobs until their health eventually forced them out, and their quality of life was often not very good after they retired. McCarver didn't want that for himself.
A wine aficionado with a second home in California's Napa Valley, he'd love to travel to Italy for cooking classes.
"I plan on living a very long life, believe me," McCarver said. "I hope Mother Nature cooperates."
McCarver could still appear on Fox or its new cable network, Fox Sports 1, in a different role in the future. But until he tests out retirement, he can't predict whether he'll still want to do a little broadcasting.
McCarver will call a full schedule of games for Fox this season. There was no discussion Wednesday of who might replace him in the booth for 2014.
McCarver has worked 28 consecutive MLB postseasons on network television, providing analysis for a record 23 World Series.
Fox Sports Chairman David Hill recalled how he and then-President Ed Goren "would sit in the truck and look at each other when Tim would say, 'This is going to happen,' and it did."
"We knew it wasn't guessing," Hill said, "because to use the term 'guessing' there's an element of doubt. Tim would know."
McCarver got his start in broadcasting in 1980 with the Philadelphia Phillies and NBC's "Game of the Week." He has also called local games for the New York Mets and Yankees and the San Francisco Giants.
"You've always been a great symbol of class," Commissioner Bud Selig told McCarver on the conference call.
McCarver spent 21 seasons in the majors between 1959 and 1980, mostly with the Cardinals and Phillies. He was a two-time All-Star and won the World Series in 1964 and 1967 with St. Louis. A career .271 hitter, McCarver had 97 home runs and 645 RBIs.
He missed the start of the 2011 AL championship series because of a minor heart-related procedure, but the test result that necessitated that medical work turned out to be a false positive.
"I've learned more from him than anybody I've ever been around in this business," Joe Buck said, "including my father."