This paper investigates the impact of medical and consumerinterests on the choice of physician licensing requirements inthe United States. Using data on licensing requirements in thefifty states between 1986 and 1993, we find that, in general,public members on licensing boards are associated withlicensing requirements that have educational justification. Incontrast, medical interests, measured in terms of licensingboard independence and campaign contributions by medicalassociations, are associated with licensing requirements thatare more difficult to justify with educational criteria.