Medicaid is a joint federal-state program that finances the delivery of primary and acute medical services, as well as LTSS, for a diverse low-income population, including children, pregnant women, adults, individuals with chronic disabling conditions, and people age 65 and older. This book describes the basic elements of Medicaid, focusing on who is eligible, what services are covered, how enrolees share in the cost of care, how the program is financed, and how providers are paid. The book also explains waivers, program integrity activities, and the dual eligible population. In addition, the book describes the following selected issues: the ACA Medicaid expansion, the impact of the ACA health insurance annual fee on Medicaid, and the ACA maintenance of effort (MOE) with respect to Medicaid eligibility.