ESPN— The Chiefs and star quarterback Patrick Mahomes have reached agreement on a 10-year contract extension that ties him to Kansas City through the 2031 season, the team announced Monday.

League sources told ESPN’s Adam Schefter that the deal is worth $450 million over the 10-year period.

The injury guarantee in the contract is $140 million, a source told Schefter.

The Chiefs picked up Mahomes’ fifth-year option for the 2021 season in April, putting him under contract for the next two seasons. Mahomes had two years and $27.6 million left on his existing deal — $2.8 million this year, $24.8 million in 2021. The 10-year extension puts him under contract with the Chiefs for the next 12 seasons.

With a payout of at $477.6 million over the next 12 seasons, Mahomes will have the largest contract in American professional sports. Mike Trout had previously held that distinction when he signed a 12-year, $426.5 million contract with the Los Angeles Angels in March 2019. Trout’s contract is fully guaranteed, however.

Patrick Mahomes: Past 2 Seasons

Including the playoffs, Patrick Mahomes leads the NFL in touchdown passes, passing yards, yards per attempt, Total QBR and wins as a starter over the past two seasons.NFL RANKPass TD891stPass yards10,6021stWins271stTotal QBR791stYards per att.8.51st— ESPN Stats & Information

Mahomes tweeted about the deal following its announcement Monday.

Patrick Mahomes: Past 2 Seasons

Including the playoffs, Patrick Mahomes leads the NFL in touchdown passes, passing yards, yards per attempt, Total QBR and wins as a starter over the past two seasons.NFL RANKPass TD891stPass yards10,6021stWins271stTotal QBR791stYards per att.8.51st— ESPN Stats & Information

Mahomes becomes the fourth quarterback since 2011 to receive an extension before the start of his fourth season, joining Ryan Tannehill (Miami Dolphins in 2015), Carson Wentz (Philadelphia Eagles in ’19) and Jared Goff (Los Angeles Rams in ’19).

The Chiefs had said they intended to sign their franchise quarterback to an extension but had previously indicated it might not happen until after this season.

Mahomes, 24, was MVP of Kansas City’s 31-20 victory over the San Francisco 49ers in Super Bowl LIV, becoming the first quarterback in NFL history to win a league MVP and Super Bowl before turning 25.

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