Gilpin is a graduate of Phillips Exeter Academy (class of 1969) and Harvard University (class of 1973). He studied acting at the Neighborhood Playhouse school of the theatre in New York City. In 2008, Gilpin appeared in the fact-based film 21, playing the role of Bob Phillips who is interviewing student candidates for the fictional "Robinson Scholarship" to attend Harvard Medical School. Gilpin's character appears in the first scene of the film and his words set the stage for the movie's plot; he appears again in the final scene to bring closure to the film.