Medicare is a single-payer federal health insurance program created to provide health coverage for Americans aged 65 and older and later expanded to cover younger people who have permanent disabilities or who have been diagnosed with end-stage renal disease or amyotrophic lateral sclerosis (ALS).
Medicare is comprised of Medicare Part A (hospital insurance) and Medicare Part B (outpatient coverage). Enrollees also have the option to purchase Medicare Part D (prescription coverage) and a Medigap supplement, or to wrap everything into a Medicare Part C plan (Medicare Advantage).
Medicare A is free for most enrollees, as they’ve paid for it with payroll taxes over their working years. There are premiums for the other parts of Medicare, but they’re also subsidized by tax dollars.
Learn more about Medicare benefits and eligibility.