ABC's "Private Practice" will be calling it quits after its 13-episode, 6th-season run, show creator Shonda Rhimes announced.

The "Grey's Anatomy" spinoff, starring Kate Walsh, will have an abbreviated final season because the network opted not to pick up the planned final nine episodes, Rhimes said in a series of tweets.

"There was a lot of discussion and debate but, in the end, the guys at the network and the studio and I all decided that 'Private Practice' was reaching its finish line," she said. "It's heartbreaking to end. Truly. I feel so lucky to write for these characters and tell these stories and I truly feel this show has taught me so much as a writer."

Viewership for the California-set medical drama dropped off last season when it was moved from its post-"Grey's Anatomy" slot on Thursdays to Tuesdays after "Dancing With the Stars," The Hollywood Reporter reported Friday.

"Private Practice" had a first-season average of 11.5 million viewers, which has slipped to 6.1 million this season.