Every Grey’s Anatomy doctor exit, ranked from most heartbreaking to most satisfying, from Meredith Grey to McDreamy, Cristina Yang, and beyond. Created by Shonda Rhimes, Grey’s Anatomy has seen numerous cast members enter and exit the show throughout its tenure. She joined Grey’s Anatomy in season 5 and went on to be a series regular until season 14. 7 Dr. Izzie Stevens (Katherine Heigl)Katherine Heigl in Grey’s Anatomy | Credit: ABCActress Katherine Heigl’s exit from Grey’s Anatomy was marred by controversy. Though Grey’s Anatomy jump-started the actress’s career, she went on to star in multiple romcoms and establish a place in the industry for herself.