 The series was created to be racially diverse, utilizing a color-blind casting technique. It revolves around the title character Dr. Meredith Grey played by Ellen Pompeo. The series'original cast consisted of nine star billed cast members including Ellen Pompeo, Sandra Oh, Katherine Heigl, Justin Chambers, T. R. Knight, Chandra Wilson, James Pickens Jr., Isaiah Washington and Patrick Dempsey. The cast has undergone major changes throughout the run of the show, with many major cast members leaving and being replaced by several new characters. The series in its twelfth season had a large ensemble of sixteen actors, including four from the original cast. On March 3, 2016, ABC renewed Grey's Anatomy for a thirteenth season, scheduled to premiere on September 22, 2016.
