The profession of medicine is based on a shared set of tacit and explicit agreements about what patients, doctors, and society at large should be able to expect from each other, a social contract that defines the profession. Historically, the development of this set of agreements depended upon the creation of social organizations that could speak for the entire profession. Over the last several decades, however, the perceived need for these organizations, and especially the umbrella organization for the profession, the American Medical Association, has waned. The reasons for this are complex, but the consequences are significant: an eroding social contract, fragmentation, lack of cohesion and integrity, and loss of the public's confidence. The present social contract is one-dimensional, overly simplistic, and failing to sustain the public's trust. To address these problems, a renewed social contract is necessary. Although this renewed contract should be based on foundations similar to the original, it must directly confront such contemporary challenges as resource allocation and conflicts of interest. Equally as important, to reinvigorate our social contract more physicians will need to come to grips with a basic truth: to sustain professionalism we need a strong, unified professional association.