Isaiah Hartenstein is staying in Oklahoma City for the long term after agreeing to a new contract that keeps one of the NBA’s top defensive centers with the Thunder through the 2028-29 season.
NBA insider Shams Charania reported Friday that Hartenstein intends to sign a new three-year extension worth $75 million in new money. The agreement raises his total earnings with the franchise to five years and $134 million guaranteed. The deal also includes a maximum 15% trade kicker and an uncommon mutual option that allows both sides to revisit the contract in 2028 before the final season.
The extension removes what had been one of Oklahoma City’s biggest offseason questions. Hartenstein held a $28.5 million team option for the 2026-27 season, and league executives had debated whether the Thunder would simply exercise that option or decline it in favor of negotiating a longer-term contract with a lower annual cap hit. Instead, the sides reached a compromise that provides financial security for the player while maintaining continuity for one of the NBA’s premier contenders.
Hartenstein arrived in Oklahoma City ahead of the 2024-25 season and quickly became a foundational piece of the Thunder’s frontcourt. His first season ended with an NBA championship, and he followed it by helping Oklahoma City finish with the league’s best regular-season record at 64-18 in 2025-26.
Although the Thunder fell to the San Antonio Spurs in seven games in the Western Conference Finals, Hartenstein remained one of the team’s most important postseason contributors. His physical interior defense, rebounding, screening and passing complemented MVP candidate Shai Gilgeous-Alexander and Oklahoma City’s perimeter-heavy attack.
Following the season, Hartenstein made it clear that he hoped to remain with the organization.
“Yeah, I love being here. I love the organization,” Hartenstein said after the Thunder’s playoff exit. “It’s a business at the end of the day, but again just whatever happens I’m truly grateful.”
He also highlighted the connection he has built with Oklahoma City’s fan base and community.
“The community is big,” Hartenstein said. “Since I got here I really started connecting with the community and just how they approach giving back, how they approach being selfless.”
Hartenstein expressed confidence in his defensive impact during the Western Conference Finals, particularly against Spurs star Victor Wembanyama.
“I think I did a good job,” he said. “I got him most of the time to the stuff I wanted to get him to… I think I kind of proved that I can defend players like that.”
