Private Practice ended after Kate Walsh's exit, and the declining ratings in season six prove that the series was cancelled at the right time.

Private Practice ran for a total of six seasons before a few factors resulted in the show's cancellation in 2013. The Grey’s Anatomy spinoff showed Addison Montgomery (Kate Walsh) leave Seattle Grace Hospital and move to a private practice in Los Angeles. While the series found success in its own right, it never quite received the same level of attention as Grey’s.

The ABC series first debuted as a backdoor pilot during Grey’s Anatomy season 3. It ran from 2007 to 2013 and followed Addison and a new cast of characters at Oceanside Wellness deal with medical cases and their love lives and had five crossover storylines with Grey's. It was ultimately canceled after a 13-episode run in its sixth season, while its predecessor is currently heading into its 18th season. After the conclusion of Private Practice, the character of Amelia Shepard joined Grey’s as a series regular.

The news that Private Practice season 6 was the final installment came after it was announced that Walsh was exiting the show. Walsh said goodbye to the role of Addison Montgomery after playing her for 7 years, first on Grey’s Anatomy and then as the main lead in the spinoff series. Her deal was up at the end of season five, but as reported (via Deadline), the actress agreed to return for 13 additional episodes after some negotiation. From there, it just made sense for all parties to say goodbye to Private Practice.

Since the show was built around Kate Walsh’s character, it was unclear how the series would continue without her. There was speculation even before season six aired that it would be the last season, and in October of 2012, it was confirmed that ABC Studios and Grey’s Anatomy and Private Practice executive producer Shonda Rhimes decided that the spinoff would end. Rhimes announced the cancellation (via Twitter), stating that she was proud of the series, but after much debate, she felt that Private Practice had run its course. Season 6 worked as an extended finale, wrapping up the storylines of each main character, with the very last episode featuring Addison and Jake’s wedding.

Concluding the series was the right decision because if the season had continued beyond episode 13, Kate Walsh would not have been the only cast member who left before the end. It was announced in May of 2012 that Tim Daly's Pete Wilder would not be returning in season 6. Even before that, Audra McDonald (who played Naomi Bennett) left at the end of season 4, and Chris Lowell’s character, Dell Parker, was killed off in the season 3 finale.

Compared to Grey’s Anatomy and Scandal, the other two Shondaland series on the air in 2012, Private Practice fell short in terms of ratings. The viewership over the seasons was on a steady decline, with only 6.45 million US viewers tuning in for the season six premiere. In fact, it was reported (via EW) that Scandal’s first season premiering just a year before in 2011, knocking Private Practice out of its Thursday time slot to Tuesday, caused the show to lose nearly 20% of its viewers. With the impending departure of Kate Walsh and the decreasing viewership, ending the series after five and a half seasons was the right call.

More: Grey's Anatomy Season 17 Finally Got Character Exits Right