Medicaid is a means-tested entitlement program that finances the delivery of primary and acute medical services as well as long-term care. Medicaid is jointly funded by the federal government and the states. The federal government's share of a state's expenditures is called the federal medical assistance percentage (FMAP) rate. The remainder is referred to as the nonfederal share, or state share. Estimates of Medicaid spending developed from Centers for Medicare & Medicaid Services (CMS) data sources suggest wide variation among states in Medicaid spending per enrollee, overall and for each of four main eligibility groups—children, adults, disabled, and aged. This book examines Medicaid spending per enrollee by state; selected factors that influence Medicaid spending per enrollee, by state; and how states account for factors that influence expected per-enrollee spending when setting rates for Medicaid managed care plans.