Wikipedia:
Unlike Medicare, which is solely a federal program, Medicaid is a joint federal-state program. Each state operates its own Medicaid system, but this system must conform to federal guidelines in order for the state to receive matching funds and grants.[37] The matching rate provided to states is determined using a federal matching formula (called Federal Medical Assistance Percentages), which generates payment rates that vary from state to state, depending on each state's respective per capita income.[38] The wealthiest states only receive a federal match of 50% while poorer states receive a larger match.