Sandra Oh is leaving the cast of ABC’s smash medical drama Grey’s Anatomy, The Hollywood Reporter (THR) has learned. The actress is one of six original castmembers –Patrick Dempsey, Ellen Pompeo, Chandra Wilson, Justin Chambers, James Pickens Jr. and Chandra Wilson — still with the series.

But that will change at the end of the show’s upcoming 10th season.

Oh’s earned five supporting actress Emmy nominations for her work as spitfire Dr. Cristina Yang on the series and feels she’s all tapped out creatively.

“Creatively, I really feel like I gave it my all, and I feel ready to let her go. It’s such an interesting thing to play a character for so long and to actually get the sense that she wants to be let go as well. [My character Cristina] wants to be let go, and I am ready to let her go. We have to start the process, storywise, for the Grey’s writers to think of why she’s going to go.”

She added:

“I want this to be a celebration. I want us to get to that point where we see this character ride off into the sunset…Grey’s has been the most important role of my life. Playing Cristina and growing her and growing myself in her, I want to usher her into the next section of her life in the best way possible. It’s got to be Cristina Yang’s happily ever after.”

Series creator Shonda Rhimes is disappointed to learn of Oh’s departure, but has promised the Yang character the send off she deserves. The showrunner told THR:

“One of the best days of my life as a writer happened the day Sandra Oh walked in my door to audition and forever changed the course of Grey’s Anatomy with her brilliant, nuanced portrayal of Cristina Yang. Over the past 10 seasons, I have been made better by Sandra’s trust, faith, and friendship…When Sandra walks out of my door, Grey’s Anatomy will once again be forever changed.”

The 10th season of Grey’s Anatomy premieres Sept. 26 on ABC.