Medicaid is a joint federal and state health insurance program that provides free or low-cost coverage to millions of low-income Americans, including children, pregnant women, elderly adults, and people with disabilities. It is the largest source of health coverage in the United States, covering over 90 million people.
The federal government establishes minimum requirements for Medicaid, but each state administers its own program with its own name, eligibility rules, and benefits. Under the Affordable Care Act, states were given the option to expand Medicaid to cover all adults with incomes up to 138% of the Federal Poverty Level (FPL). As of 2025, 40 states plus the District of Columbia have adopted Medicaid expansion.
Medicaid is funded jointly by the federal government and state governments. The federal government pays at least 50% of Medicaid costs (more for expansion populations at 90%), with the exact share determined by each state's per capita income through the Federal Medical Assistance Percentage (FMAP).