Since the 1990s, the HIV/AIDS epidemic has increasingly impacted minority groups in the United States, particularly African Americans. Why is this happening? Comparative studies of developing nations have convincingly established a relationship between concentrated poverty, ethnic boundaries, and lack of effective governmental response as contributing to high levels of infection in those countries. To date, however, no study has sought to apply these insights to the American context. This dissertation endeavors to show that, first, marginalization of U.S. sub-groups most at risk of infection is largely a product of poor health outcomes associated with concentrated urban poverty and economic stratification. Second, this sub-group marginalization is exacerbated by the politics of retrenchment which increasingly privatizes risks onto individuals, states, and non-governmental providers. The net result of these changes is a U.S. health care system too fractured to recognize and respond to changes in HIV/AIDS demographics.