Zach Braff Dr. John "J.D." Dorian Actor Sarah Chalke Dr. Elliott Reid Actor Donald Faison Dr. Chris Turk Actor John C. McGinley Dr. Perry Cox Actor Judy Reyes Nurse Carla Espinosa Actor Ken Jenkins Dr. Bob Kelso Actor Neil Flynn The Janitor Actor Colin Farrell Billy Guest Star Robert Maschio Todd Guest Star Christa Miller Jordan Guest Star Aloma Wright Nurse Roberts Guest Star Michael Bunin Jerry Guest Star Dan Magner Policeman 1 Guest Star Matthew Pohlson Patient Guest Star Myra Turley Woman Guest Star Skip Wright Doctor Guest Star Bill Lawrence Executive Producer Chris Koch Director Mike Schwartz Writer