As the number of people seeking HIV care in the U.S. has grown, the demand has increased not only for medical care, but also for a wide range of supportive services. This in turn has increased the need for demonstrated and tested HIV care service models that can address a comprehensive set of needs. The Special Projects of National Significance (SPNS) Program's HIV Innovative Models of Care Initiative funded by the Health Resources and Services Administration (HRSA) began on October 1, 1994. This initiative is an effort by 27 HRSA-funded projects to jointly establish goals and objectives, develop common evaluation methods, and produce comparable and measurable outcomes for innovative models of HIV care. The five projects of the SPNS Program Capitated Care Work Group share, as a central theme, the study of the health care provided to individuals with HIV disease under models where the health care is capitated, or paid on a "flat fee" basis per patient per month. These projects differ in the ways that they provide health care, ranging from community- and university-based clinics to a home-based hospice to a statewide health care system. Each of the projects shares the goals of determining costs for providing health care services to AIDS patients under a capitated care system and of ensuring that high quality care is provided under such a system.