Physicians, like all citizens, have communal and private identities, each attending various associated roles and fulfilling diverse obligations. In light of these dual personae, we seek a moral philosophy which encompasses the responsibility for providing care to the patient and at the same time acknowledges the physician's role of arbiter of distributed care. In the traditional doctor/patient relationship, rationing, the admission that health resources are limited and must be distributed equitably by universally accepted criteria, is essentially ignored. When the physician assumes a population-based system of ethics to optimize care for all patients within a group, rationing is embraced as the realistic admission that any social action resides within boundaries--in this case health care resources--and that such restraints have economic consequences that present ethical choices. A common ground to accommodate these dual allegiances is offered by communitarian philosophy, whose outline and applicability is presented here as an alternative to the apparent moral opposition of optimized individual care and the requirement of community-wide distribution of limited health resources.