Republicans are eyeing cuts to Medicaid. What is Medicaid, and how is it different from Medicare?

In January, during a congressional hearing on his way to becoming secretary of the Department of Health and Human Services, Robert F. Kennedy Jr. got basic details wrong about Medicaid — a program he now oversees.

He said that Medicaid is fully funded by the federal government (it’s not) and that many enrollees are unsatisfied with high out-of-pocket costs (enrollees pay limited, if any, out-of-pocket costs).

Medicaid is complex. The $880 billion-a-year state-federal program offers health coverage to millions of disabled and low-income Americans. The program covers different services for different people in different parts of the country — and enrollees may interact with private insurance companies without “Medicaid” in their names, leaving some unaware that they’re on the program at all.

Although President Donald Trump promised to “love and cherish” Medicaid, Republicans in Congress last week announced federal budget proposals that could dramatically curtail the program. As that debate begins, here is what you need to know about Medicaid.