Medicaid is at the center of the current national policy debate. Republican proposals to partially repeal the Affordable Care Act (ACA) include substantial changes to Medicaid that could affect more than 70 million US individuals. How Medicaid works, whom it covers, and how it is funded is a complicated but critical topic. This Viewpoint summarizes the main features of the Medicaid program and how proposed legislation might affect it.
Medicaid has become the nation’s largest source of health insurance, covering 77 million people in 2017 (Box). Yet this statement belies the multifaceted nature of the program, which covers numerous populations with different program features. One portion of Medicaid functions largely as a health insurance program for low-income families. Contrary to popular perception, however, not all poor US residents are eligible for the program. Prior to the passage of the ACA, coverage was available only to low-income individuals in these categories of eligibility: children, pregnant women, parents, elderly adults, and people with disabilities.