Social Security: Last year, 24 percent of the budget, or $916 billion, paid for Social Security, which provided monthly retirement benefits averaging $1,360 to

Social Security: Last year, 24 percent of the budget, or $916 billion, paid for Social Security, which provided monthly retirement benefits averaging $1,360 to 41 million retired workers in December 2016. Social Security also provided benefits to 3 million spouses and children of retired workers, 6 million surviving children and spouses of deceased workers, and 10.6 million disabled workers and their eligible dependents in December 2016. Medicare, Medicaid, CHIP, and marketplace subsidies: Four health insurance programs — Medicare, Medicaid, the Children’s Health Insurance Program (CHIP), and Affordable Care Act (ACA) marketplace subsidies — together accounted for 26 percent of the budget in 2016, or $1 trillion. Nearly three-fifths of this amount, or $594 billion, went to Medicare, which provides health coverage to around 57 million people who are over age 65 or have disabilities. The rest of this category funds Medicaid, CHIP, and ACA subsidy and exchange costs. In a typical month, Medicaid and CHIP provide health care or long-term care to about 74 million low-income children, parents, elderly people, and people with disabilities. (Both Medicaid and CHIP require matching payments from the states.) In 2016, 9 million of the 11 million people enrolled in health insurance exchanges received ACA subsidies, at an estimated cost of about $31 billion.