The American Board of Medical Specialties Maintenance of Certification Program (ABMS MOC) is designed to provide a comprehensive approach to physician lifelong learning, self-assessment, and quality improvement (QI) through its 4-part framework and coverage of the 6 competencies previously adopted by the ABMS and the Accreditation Council for Graduate Medical Education (ACGME). In this article, the theoretical rationale and exemplary empiric data regarding the MOC program and its individual parts are reviewed. The value of each part is considered in relation to 4 criteria about the relationship of the competencies addressed within that part to (1) patient outcomes, (2) physician performance, (3) validity of the assessment or educational methods utilized, and (4) learning or improvement potential. Overall, a sound theoretical rationale and a respectable evidence base exists to support the current structure and elements of the MOC program. However, it is incumbent on the ABMS and ABMS member boards to continue to examine their programs moving forward to assure the public and the profession that they are meeting expectations, are clinically relevant, and provide value to patients and participating physicians, and to refine and improve them as ongoing research indicates.