Many health care professionals have sustained an almost single-minded conviction that disparities in access to health care across socioeconomic groups are the key reason for the major discrepancies in health status between wealthy persons and poor persons. Others, however, have argued that a host of factors work to create major impediments and that reducing or eliminating financial barriers to health care in particular will do little to reduce discrepancies in health status. This paper, while acknowledging the spectrum of contributing factors, argues that the elimination of financially based differences in access is central to any effort to create equity in outcomes across socioeconomic groups. Through selected review of the many studies on health insurance, access, outcomes, and socioeconomic status, it establishes that a core links affected populations, their difficulty in financing health care, and the threat to their well-being. In so doing, it cites findings that strongly associate lack of insurance (especially for persons who live in poverty), inability to obtain services, and adverse health outcomes. It also uses the example of Medicaid and other coverage for HIV-infected persons in particular as an important positive instance in which leveling the discrepancies in health care across socioeconomic groups can move toward creating quality in access and outcomes. The competitive pressures in today's health care environment threaten to drive socioeconomic groups further apart, especially insured and uninsured persons. However, the recent enactment of state actions, especially the State Child Health Insurance Program, represent powerful examples of health insurance expansion that have lessons for policymakers at all levels for the monitoring and reduction of socioeconomic disparities.