In recent years, State Medicaid programs have begun adopting health-based payment systems to help ensure quality care for people living with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS), and to ensure equity for the managed care organizations (MCOs) in which these people are enrolled. In this article, the authors discuss reasons why such payment systems are needed and describe AIDS-specific capitation rates that have been adopted in several State Medicaid waiver programs. The authors also examine comprehensive risk-adjustment systems both within Medicaid and outside the program. Several research questions needing further work are discussed.