For five decades, medical education policy in the United States has been built around the expectation that, if too few physicians were produced, additional physicians would be available from other countries. That policy is examined in the context of the desire for an ever-increasing number of physicians who will provide an ever-expanding array of services in the future. This reality is juxtaposed against the realities that the medical education infrastructure in the United States has yet to respond to the projected needs of the future. Also, other countries have growing needs for English-speaking physicians, particularly the developing countries from which most such physicians migrate. I explore the history of physician migration to the United States, catalogue the countries of origin, examine the attitudes of current students and physicians about migration, and consider the consequences that are likely for donor countries if even higher levels of migration are stimulated. I conclude that the deepening shortages of physicians now being experienced in this country cannot be rectified without substantial increases in the flow of physicians from developing to developed countries. The challenges that this will create call for mutual understanding and a high degree of discipline and creativity among all countries if global health care needs are to be respected.