The series begins on Howser's 16th birthday; the cold open of the pilot episode shows him stopping his field test for his driver's license to help an injured person at the scene of a traffic accident. Howser is a second-year resident surgeon at Eastman Medical Center in Los Angeles, and still lives at home with his parents. His best friend and neighbor, Vinnie Delpino (Max Casella), is a more typical teenager—climbing through Howser's bedroom window to visit—and connects him to life outside of medicine. Howser has kept a diary on his computer since 1979; episodes typically end with him making an entry in it, making observations about the situations he had experienced or learned in the episode.