Health services research has laid the groundwork for ongoing policy debates over the shortcomings of the American health care system and the need for the expansion of health insurance protection. In the early 1970s, studies of inequality in access to medical care provided the basis for proposals for national health insurance. The examination of the impact of Medicare and Medicaid demonstrated the critical role of these governmental efforts in reducing inequalities in access to care. By the 1980s the focus of investigation turned to the impact of policies designed to contain the cost of health care on access to medical services by vulnerable populations. Documentation of the negative health outcomes that followed from restrictions on access to care has set the stage for a renewed debate over universal health insurance.