The contract includes a $20 million club option for 2023 with no buyout.
The 37-year-old right-hander has been a stalwart of the rotation for the first-place Braves, going 13-5 with a 3.47 ERA in 28 starts.
The deal comes 2½ weeks after the Braves reached a similar, low-risk move with catcher Travis d'Arnaud. He agreed to a two-year, $16 million contract beginning next season, with an $8 million club option for 2024 that doesn't have a buyout.
The Braves signed Morton to a one-year, $15 million contract in free agency after he helped the Tampa Bay Rays reach the 2020 World Series. It marked a return to the franchise where he began his career in 2008.
Morton has been a huge addition to the Braves, especially after former ace Mike Soroka tore an Achilles tendon for the second time and was ruled out for the season.
With Soroka's future uncertain, Morton provides additional depth for 2022. The right-hander has lasted at least six innings in 17 of his 28 starts, and failed to go at least five innings only three times.
Morton picked up his 13th win on Sunday, pitching two-hit ball over seven innings in a 9-2 win at Colorado. The Braves, who were off Monday, hold a two-game lead over Philadelphia in the NL East as they seek their fourth straight division title.
"I don't think any moment is too big for him," d'Arnaud said. "Whenever we need him, he always shows up."
Morton has been especially valuable at taking pressure off the Braves' bullpen.
"It's not really about yourself. It's about what's best for the team," he said. "Those guys have been grinding. Every year now, the starters are going fewer innings and bullpens are having to wear it. It's nice to feel like I've done my part in that regard."
Morton has been a late bloomer in a career that also includes stints with Pittsburgh and Houston. He has won at least 13 games in each of the past four full seasons (excluding the pandemic-shortened 2020 campaign) and earned two All-Star Game appearances.
Since the beginning of the 2017 season, Morton is 60-23 with a 3.37 ERA -- the fourth-most wins by a big league pitcher over that span. Before 2017, he had never won more than 10 games in a season.
If the Braves earn another division title, they're counting on Morton to be a big contributor. He has a 7-3 mark in 13 postseason appearances, including four wins in winner-take-all games -- the most in major league history.