This data was updated in March 2019. Please see "Medicaid Makes Up Most Federal Grants to States."
Medicaid is by far the largest federal grant to states, accounting for 67 percent of total grant funding in 2017. The next-largest funding area is income security (temporary cash assistance, employment services, school-provided meals, and similar programs), which at 13 percent is one-fifth the size of Medicaid. Medicaid was the main driver of the 40 percent increase in total federal grants to states from 2008-17.