Physicians have a key role in reforming US medical care. The fundamental problem with the health care system is its high, uncontrollable cost, and that cost is largely determined by the elective decisions of physicians to use medical resources. Health policy experts increasingly suggest that controlling these physician-generated costs will require a change from fee-for-service to some type of global payment, and the formation of accountable care organizations (ACOs) in which integrated multispecialty groups of physicians will be able to share global payments with hospitals and other providers.1