Medicaid accounts for about one-fifth of state budgets, on average.

From The New York Times:

The bill passed by the Senate on Thursday would move toward universal health insurance coverage in large part by expanding Medicaid, a program whose costs have traditionally been shared by the states and the federal government.

Medicaid covers about 60 million Americans, mostly low-income families and pregnant women, though some states have expanded eligibility to include childless adults under 65. It accounts for about one-fifth of state budgets, on average.