The incoming U.S. administration is planning sweeping changes in the federal government's approach to medicine and public health. Republicans control both houses of Congress and the conservative Supreme Court, increasing the potential for change if internal disagreements are resolved. Changes will focus on health insurance provided through Medicaid for low-income people, Medicare for people over 65 and the disabled, or private insurance through employers or exchanges under the ACA. Most Medicaid, Medicare, and ACA exchange policies are decided at the federal level, but health care is administered by the states. Health care outcomes will depend on states adapting to changes in federal policy or funding. The article mentions policy challenges related to Medicare and Medicaid.