Patrick Mahomes Gets 10-Year Deal With Kansas City Chiefs

The contract extension, which was first reported by ESPN, is the largest in N.F.L. history and one of the biggest in U.S. sports. Leigh Steinberg, Mahomes’s agent, said the extension was worth $503 million. Steinberg said $477 million of that money was in “guarantee mechanisms” and that Mahomes could opt out if those mechanisms were not triggered. Mahomes also will have a no-trade clause.

A spokesman for the Chiefs declined to comment. Mahomes and the Chiefs began negotiations in May.

Ten-year contract extensions are unusual in the N.F.L., where the injury rates are high and teams operate under a strict salary cap that limits how much they can spend on their rosters. Most star quarterbacks have received three- and four-year contracts in recent years. Russell Wilson, for instance, signed a four-year, $140 million extension with the Seattle Seahawks last year, which at the time made him the league’s highest paid player, with the biggest signing bonus — reportedly $65 million — in history.

The last time an N.F.L. player signed a 10-year contract was in 2004, when quarterback Michael Vick, then 24 and with the Atlanta Falcons, agreed to a deal worth as much as $130 million. That made him the highest-paid player at the time.

But the Chiefs no doubt recognize that Mahomes is a once-in-a-generation player with a combination of athletic ability and star power that is nearly impossible to replicate. Agents for other young, talented quarterbacks, most notably Dak Prescott of the Dallas Cowboys, are likely to use Mahomes’s contract to justify seeking similar deals for their clients.

Lamar Jackson of the Baltimore Ravens and Deshaun Watson of the Houston Texans, two other cornerstone quarterbacks, are also still playing on rookie deals.