In the United States, Canada, and the United Kingdom, the medical profession is accountable to the public for the delivery and quality of care provided to patients. Traditionally, this accountability has been achieved through the development and maintenance of professional standards established by the profession itself-self-regulation. Medical self-regulation is being re-examined by regulators, government, and the profession in response to a range of drivers including payers seeking ways to hold physicians accountable for cost-effective care; patients seeking more information about their physician's qualifications; and the emergence of a number of high-profile cases of unacceptable medical practice. This article outlines the current state of medical regulation in the United States, Canada, and the United Kingdom and highlights the increasing external pressure on the self-regulatory framework that is leading to a shift toward shared regulation between the profession and other stakeholders.