The Oklahoma City Thunder have agreed to a three-year, $75 million extension with center Isaiah Hartenstein, keeping him under contract through the 2028-29 season. The deal adds new money and includes a maximum 15 percent trade kicker as well as a mutual option that allows both club and player to revisit the terms after the first year.

Hartenstein, 28, originally signed a three-year, $87 million contract with Oklahoma City before the 2024-25 campaign, which contained a $28.5 million team option for the 2026-27 season. The new extension replaces that option with fresh cash and the aforementioned flexibility.

The 7-foot center was a key piece in the Thunder’s 2025 championship run, averaging 11.2 points per game during that season. This year he posted 9.2 points per game while shooting an efficient 62.2 percent from the field. He has started for two consecutive seasons, and Oklahoma City has gone 88-16 in the regular season when he is on the floor. In the 2025 playoffs he started 20 of the 23 games the Thunder played.

“Hart has been great,” Oklahoma City executive vice president and general manager Sam Presti said at the close of the season. “He’s been a big factor in a lot of our success. Also, I know whenever I talk about him, I never want to not mention just the amount of community work this guy has done here in such a short amount of time. Just unbelievable. Him and his family, they have put two feet into this community and given it a huge hug. He’s been wonderful off the floor as well.”

The extension comes as the Thunder have already moved two bench players, sending Aaron Wiggins to Atlanta and Isaiah Joe to Detroit. Those moves illustrate the front office’s willingness to adjust depth while preserving the core that delivered the title.

Retaining Hartenstein preserves a versatile interior presence that can stretch the paint with his shooting touch and protect the rim with his size. His ability to space the floor and defend multiple positions fits the Thunder’s switch-heavy defensive scheme and gives the coaching staff flexibility in lineup construction. By locking him up early, Oklahoma City avoids a free-agency scramble for a similar skill set and maintains continuity around its young stars.

With the contract in place, the Thunder can focus on complementing their existing core rather than replacing a proven contributor. The mutual option provides a safety valve for both sides, allowing the club to reassess roster composition after the first year of the extension. As the team looks ahead to the next three seasons, Hartenstein’s blend of efficiency, size, and community leadership positions him as a cornerstone of Oklahoma City’s continued pursuit of championships.