Established in 1939, the American Osteopathic Association's (AOA) Bureau of Osteopathic Specialists (BOS) is the supervisory body for the AOA's 16 Specialty Certifying Boards in the United States. The BOS establishes and enforces policy for board certification through the AOA Specialty Certifying Boards and maintains high standards for certification by developing and implementing educational and professional standards used to evaluate and certify osteopathic and non-osteopathic physicians.