This article investigates the relationship between the characteristics of medical licensing boards and the frequency with which boards discipline physicians. Specifically, we take advantage of variation in the structure of medical licensing boards between 1993 and 2003 to determine the effect of organizational and budgetary independence, public oversight, and resource constraints on rates of physician discipline. We find that larger licensing boards, boards with more staff, and boards that are organizationally independent from state government discipline doctors more frequently. Public oversight and political control over board budgets do not appear to influence the extent to which medical licensing boards discipline doctors. These findings are broadly consistent with theories of regulatory behavior that emphasize the importance of bureaucratic autonomy for effective regulatory enforcement.