Mahomes agreed to a 10-year extension worth up to $503 million, according to his agency, Steinberg Sports. The deal is worth $477 million in guarantee mechanisms and includes a no-trade clause and opt-out clauses if guarantee mechanisms aren't met.
It's the richest contract in professional sports history, surpassing Mike Trout's $426.5 million deal with the Los Angeles Angels. The Chiefs had the 2018 NFL MVP under contract for the next two seasons but that wasn't nearly enough.
The contract extension starts in 2022 when the NFL salary cap is projected to be $227.5 million. However, that number could be lower depending on revenue losses due to the cornonavirus pandemic and the possibility any games played this season won't have fans.