Medicaid’s original purpose was to be a safety net for people who could not adequately provide themselves with healthcare. The federal government matched funds from states to ensure eligible residents could get hospital care and physician visits. The partnership sought to strengthen state-led efforts to cover poor people who could not afford private insurance.

This idea of Medicaid being a lifeline for the poorest members of society persists in political debate and public memory, but it is no longer true. Medicaid today is the nation’s largest single source of healthcare funding, with 70 million to 80 million enrolled, just under a quarter of the population. It is the largest payer for long-term services and for mental health and substance use disorder services. In fiscal 2023, it cost taxpayers about $890 billion, with the federal government covering 69% and states contributing the remaining 31%. Medicaid spending will top $1 trillion a year by 2030, according to the Congressional Budget Office.