'Grey's Anatomy' ends when Ellen Pompeo quits

Posted November 9, 2017 8:40 a.m. EST

— "Grey's Anatomy" just hit a milestone, but its creator said she can't promise many more.

The ABC medical drama's 300th episode aired Thursday and creator Shonda Rhimes told E! the show is done once star Ellen Pompeo no longer wants to portray Meredith Grey.

"Ellen and I have a pact that I'm going to do the show as long as she's going to do the show," Rhimes said. "So the show will exist as long as both of us want to do it. If she wants to stop, we're stopping."

Rhimes said she's not sure the show will make it to 600 episodes "but I want to keep it feeling fresh."

"As long as there are fresh stories to tell and as long as we're both excited about the stories being told, we're in," she said. "So we'll see where that takes us."

Take heart though, fans. The showrunner told "Entertainment Tonight" that she believes "Grey's," now in its 14th season, will exist at least as long as NBC's hit medical series "ER," which ran for 15 seasons.

For her part Pompeo told Good Housekeeping last year that it can be challenging portraying the same character for so many years.

"Some seasons, I've been in a rut," she confessed. "It's harder to give great performances 12 years in."