To avoid losing key players in free agency, teams may look to sign them to contract extensions before they get the chance to test the open market.
The Blue Jays did just that with Vladimir Guerrero Jr. in 2025. The first baseman was due to reach free agency at the end of the season, but he signed a record 14-year, $500 million extension to stay with Toronto for the long haul.
Including Guerrero's deal, here's a look at the richest contract extensions in Major League history, in descending order of total guaranteed dollars as reported when the deals were signed. (For a list of the longest contracts -- including free agent deals -- click here.)
1. Vladimir Guerrero Jr., Blue Jays -- 14 years, $500 million
Signed in 2025, runs through 2039
Guerrero comfortably set the record for the largest contract extension, besting the previous high mark of $426.5 million set by Mike Trout and the Angels in 2019. It was no surprise, really, that Guerrero landed this kind of deal, given all of the context. In a growing economic landscape that has seen massive free-agent contracts (see, Juan Soto and Shohei Ohtani), Guerrero was the beneficiary of being a top-notch producer -- at the age of 26, no less -- for a team that needed to keep him around long term.
Signed by the Blue Jays as an international free agent in 2015, Guerrero already carried immense name value as the son of Hall of Famer Vladimir Guerrero Sr. Guerrero debuted in 2019 for the Blue Jays and put together his first MVP-caliber season in 2021, when he clubbed 48 home runs with a 1.002 OPS, finishing second in MVP award voting to Shohei Ohtani. Even as Guerrero’s production fluctuated between elite and merely solid, he entered 2025 with a .288/.363/.500 slash and a 138 OPS+.
2. Mike Trout, Angels -- 12 years, $426.5 million
Signed in 2019, runs through 2030
The Angels agreed to add 10 years and $360 million onto the two years and $66.5 million still remaining on the contract Trout signed in 2014, giving him a new 12-year, $426.5 million pact -- the richest in North American professional sports history at the time -- and ensuring the superstar outfielder would be staying in Orange County for years to come. Trout immediately rewarded the Angels’ faith in 2019 by bashing a career-high 45 home runs and winning his third career league MVP Award.
3. Mookie Betts, Dodgers -- 12 years, $365 million
Signed in 2020, runs through 2032
The Red Sox traded Betts and southpaw David Price to the Dodgers in a blockbuster trade following the 2019 season, in large part because many expected the former American League MVP to test the market following the 2020 campaign and challenge the recent free agency standards set by Bryce Harper and Manny Machado. But Los Angeles’ front office was able to hammer out a massive extension right as the shortened 2020 season was set to begin, adding on to the record one-year, $27 million contract that Betts and the Red Sox agreed to in January 2020 in order to avoid arbitration.
Making sure Betts stayed a Dodger was a no-brainer decision at the time, and proved even more so once the games got underway. Betts placed second in the 2020 NL MVP Award vote, then helped lead L.A. to a long-awaited World Series championship. Two more titles followed in 2024 and 2025.
4. Manny Machado, Padres -- 11 years, $350 million
Signed in 2023, runs through 2033
Machado originally joined the Padres on a 10-year, $300 million contract in February 2019, at the time setting a record for the largest free-agent deal in MLB history (though it has since been exceeded by several other deals). The contract gave him the ability to opt out at the end of the 2023 season, and Machado told reporters during Spring Training that he planned to exercise his opt-out power to test the open market. However, he ended up signing an extension that effectively replaced the six years left on his previous deal with a new 11-year contract running through 2033.
5. Francisco Lindor, Mets -- 10 years, $341 million
Signed in 2021, runs through 2031
Under new owner Steve Cohen, the Mets hinted that the 2020-21 offseason would be a big one in Queens, and they delivered, landing Lindor and right-hander Carlos Carrasco in a trade with Cleveland. Once that deal was done, speculation turned to whether the Mets would be able sign Lindor, a four-time All-Star and two-time Gold Glove Award winner, to a long-term extension. The two sides reached a deal on March 31, the eve of Opening Day. Lindor's 2021 salary of $22.3 million remained unchanged, and the extension -- the richest ever for a shortstop -- took effect in 2022.
6. Fernando Tatis Jr., Padres -- 14 years, $340 million
Signed in 2021, runs through 2034
After a promising but abbreviated rookie year in 2019, Tatis consolidated his promise with an electric performance in the pandemic-shortened 2020 campaign, slashing .277/.366/.571 with 17 homers in 224 at-bats and placing fourth in the NL MVP Award vote. His play was a major reason why the Padres snapped a 14-year postseason drought, and then he thrived under the brighter lights by becoming the third-youngest player to hit multiple homers in a playoff game. While the Padres missed the playoffs in 2021, Tatis finished with an NL-leading 42 homers, plus 25 steals and a .975 OPS in 130 games. Tatis missed the 2022 season with a wrist injury, followed by a suspension for a banned substance, but he returned to post a 5.5-WAR season (per Baseball-Reference) in 2023, making a successful switch from shortstop to right field.
7. Giancarlo Stanton, Marlins -- 13 years, $325 million
Signed in 2014, runs through 2028
Baseball had not seen this type of contract -- both in terms of length and total value -- before Stanton put ink to paper following the 2014 season. But the hulking slugger is playing out the majority of this deal with the Yankees, and not the Marlins; Stanton logged the first three seasons of the contract with Miami before the club traded him to New York in December 2017, shortly after he won that year’s NL MVP Award. Stanton didn't enact his opt-out clause after the 2020 season, choosing to stay in the Bronx after some injury-plagued seasons in pinstripes.
8. Rafael Devers, Red Sox -- 10 years, $313.5 million
Signed in 2023, runs through 2033
With Xander Bogaerts departing for the Padres in free agency after the 2022 season, the Red Sox put their attention on keeping their other superstar, Devers, in Boston for the long haul. A year before Devers would have reached free agency, the Red Sox reached an agreement with their two-time All-Star third baseman on the largest contract in franchise history. However, the Red Sox's relationship with Devers turned frosty after the team signed third baseman Alex Bregman in 2025, and they traded him to the Giants that June.
9. Bobby Witt Jr., Royals -- 11 years, $288.7 million
Signed in 2024, runs through 2034
The No. 2 overall pick in the 2019 MLB Draft, Witt established himself as the new face of the Royals franchise over his first two seasons. Coming off a breakout 2023 campaign that saw him produce 30 homers, 49 steals and an .813 OPS, Witt signed the richest contract in franchise history -- one that guarantees him $288.7 million over 11 years and includes four opt-outs. The contract also includes a three-year, $89 million club option (covering 2035-37) that would bring the total value of the contract to 14 years, $377.7 million.
10. Miguel Cabrera, Tigers -- 8 years, $248 million
Signed in 2014, ran through 2023
History repeated itself a bit here, as Dave Dombrowski -- the same general manager who signed Miggy to an eight-year, $152.3 million extension shortly after acquiring Cabrera for the Tigers via a trade in 2007 -- made sure Cabrera would stay in Detroit with an even bigger eight-year extension. This extension added on to the remaining two years and $44 million from Cabrera’s previous deal, and briefly positioned the slugger for the highest annual average value in history at $31 million. Cabrera certainly earned a massive extension as he was coming off back-to-back AL MVP awards (including a Triple Crown season in 2012), but injuries took their toll in the latter half of this deal and he retired at the end of the 2023 season. He's one of seven players to produce at least 3,000 hits and 500 home runs in their career.