 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 . 
