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 Robert Maschio Todd Guest Star Eliza Coupe Denise Guest Star Betsy Beutler Katie Guest Star Todd Bosley Howie Guest Star Sonal Shah Sunny Guest Star Lee Thompson Young Derek Guest Star Adam Conger Charles Guest Star Linda Tomassone Paige Guest Star Bill Lawrence Executive Producer Andy Schwartz Writer Michael McDonald Director