He graduated from Maine Township High School West in 1965; then attended the University of Chicago, where he majored in Biology, drew a draft lottery number of 3, became involved in the anti-Vietnam War movement, participated in the 1968 Democratic Convention riots, and studied with the Byronic scholar Jerome McGann.
He did a medical internship at the University of Wisconsin at Madison, then took a year-long hiatus during which he wrote his first novel, Diagnosis: Murder, which was later published by Carlyle Press, now defunct.
While working at St. John's Hospital, he and others in the emergency department there were contacted by Kathleen Kennedy and Melissa Matheson soliciting technical assistance in the resuscitation of an alien.
Elsewhere, and later, E/R – a sitcom about an emergency department starring Elliott Gould and Mary MacDonald, in which Kahn created the character of a teen orderly named Ace, played by a young George Clooney.
Among the series he worked on were Family Medical Center, Star Trek: The Next Generation, Beyond Reality, TekWar (created by William Shatner), Medicine Ball, Xena: Warrior Princess, Melrose Place (which he also co-executive produced in its last years), Star Trek: Voyager (also Supervising Producer) and All My Children (for which he and the writing staff were Emmy-nominated).