Sources tell The Hollywood Reporter that McKee — who had been with Grey's Anatomy since its debut — opted to exit after her overall deal with producers ABC Studios expired. Sources note that McKee is ready to move on in a new direction after spending 15 years within Shondaland.

McKee developed Station 19, which was born out of Grey's Anatomy's season 13 finale that featured a fire, and ran the second spinoff from the Shonda Rhimes flagship for its past two seasons. The series, which has been a stable performer in its sophomore frame, remains on the bubble for a third season. It is expected back as ABC looks to keep its TGIT-branded Thursday night lineup in place for the upcoming 2019-20 broadcast season.

A new showrunner will have to be named should Station 19 earn a third-season renewal. (Production on season two has already been completed.) A decision on the future of the show will be made in the next couple weeks ahead of ABC's formal presentation to Madison Avenue ad buyers.

Station 19 stars Jaina Lee Ortiz, Jason George and Grey Damon. Rhimes, Betsy Beers and Paris Barclay executive produce. The season two finale is set to air May 19 at 9 p.m. ET/PT on ABC. Grey's Anatomy, meanwhile, continues to be overseen by showrunner Krista Vernoff, who recently inked a sizable overall deal with ABC Studios.