2024 NBA free agency: Jayson Tatum, Celtics agree to richest contract in league history, per reports

Fresh off an NBA championship, Boston Celtics star Jayson Tatum will receive the NBA's richest contract.

The 26-year-old and the NBA's winningest franchise agreed to a supermax extension worth an estimated $315 million over five years, ending in the 2029-30 season, according to Bleacher Report's Chris Haynes and The Athletic's Shams Charania.

The deal supersedes the five-year, $304 million contract that Celtics teammate Jaylen Brown signed last season as the largest commitment in NBA history. The co-stars are owed more than $600 million. It pays to deliver wins, and Tatum and Brown have led Boston to the NBA Finals in two of the past three years.

Jayson Tatum celebrates after his Celtics won the NBA championship with a Game 5 victory over the Dallas Mavericks. (AP Photo/Charles Krupa)

This contract has been expected since Tatum made a second consecutive All-NBA First Team last season, which made him eligible for 35% of the salary cap beginning in the 2025-26 campaign. He made a third straight All-NBA First Team for good measure this past season while leading Boston to a 64-18 record — seven games better than that of any other team in the league. The Celtics also posted the third-highest net rating in NBA history.

Boston has reached six of the past eight Eastern Conference finals, including five in Tatum's seven years. He has never missed more than eight games in a season, averaging a 23-7-4 on 46/38/84 shooting splits for his career. He posted 26.9 points (47/38/83), 8.1 rebounds and 4.9 assists per game this past season.

The Celtics now have Tatum and Brown — the backbone of their recent success — signed through the end of the decade, when both will still be in their early 30s. It's a remarkable degree of stability for the defending champions, who can bring their entire playoff rotation back under contract next season. Jrue Holiday and Kristaps Porziņģis also signed extensions with Boston this past season, and Derrick White agreed to a four-year, $125.9 million extension on Monday. The Celtics' vaunted starting lineup could be under contract for at least the next two seasons, making them both an expensive team and a perennial title favorite.

Tatum's contract is more a representation of timing than his status in the league. Were any of his All-NBA brethren also coming off a rookie-scale extension, they too would receive the NBA's richest contract.

And what a time it is. Tatum's Celtics stormed through the NBA playoffs, sweeping the conference finals and winning their three other series in five games each. Their 16-3 record in the postseason is second only to the 2016-17 Golden State Warriors since the NBA moved to the current, 16-win format in 2003.

Tatum was the driving force behind that domination, even if Brown won both the Eastern Conference finals MVP and NBA Finals MVP awards. Tatum led the team in points, rebounds and assists for the entire playoffs, logging 31 points, 11 assists and eight rebounds in a title-clinching win over the Dallas Mavericks.