Isaiah Hartenstein is set to stay with the Oklahoma City Thunder through the 2028-29 season after agreeing to a new three-year contract, extending his stay to five years and $134 million guaranteed as the team faces major payroll-tax pressure from other max ex
Isaiah Hartenstein didn’t wait for the market to start circling. Friday night, the Oklahoma City Thunder moved quickly to lock in their big man with a new three-year agreement that keeps him in place through 2028-29.
The deal, reported for ESPN’s Shams Charania, is set to carry $134 million guaranteed across five years in Oklahoma City. The new contract comes at a time when the Thunder are staring down a brutal tax bill once Chet Holmgren and Jalen Williams are eligible for max extensions.
The timing matters. The Thunder previously had a $28.5 million team option for Hartenstein next season. Instead of triggering that option, they are spreading his money over more years—and lowering the yearly number—to keep the roster intact without facing a record-setting penalty.
Oklahoma City is still expected to carry one of the most expensive rosters in the league. For the franchise, the question isn’t just about keeping talent. It’s about doing it in a way that doesn’t trigger the kind of payroll consequences that can reshape a team’s flexibility for years.
Hartenstein, a 28-year-old German, signed with the Thunder in the summer of 2024 on a three-year, $87 million contract. At the time, some viewed it as an overpay. The payoff was tangible: he has been a center who rebounds, protects the rim and can pass. Oklahoma City also captured the franchise’s first championship in its current home in 2025.
This season also reinforced his value in moments that looked like tests. This spring, Hartenstein had San Antonio Spurs star Victor Wembanyama work hard during the Western Conference finals before Oklahoma City fell in Game 7. On the season, he averaged 9.2 points, 9.4 rebounds and 3.5 assists.
Beyond the numbers, his presence has changed how Oklahoma City attacks both ends. By keeping Hartenstein’s salary structured across more years, the Thunder are essentially buying continuity while they prepare for the larger financial domino effect tied to Holmgren and Williams.
The calendar is closing in for the rest of the league, too. Free agency begins June 30 at 6 p.m. ET.
Hartenstein’s path to this point has been steady but unlikely. He was taken 43rd in the 2017 draft.
Oklahoma City Thunder Isaiah Hartenstein NBA contract luxury tax Chet Holmgren extension Jalen Williams extension Victor Wembanyama NBA free agency June 30