An introduction to the Medicare program.
D014487:Centers for Medicare and Medicaid Services, U.S.; D006801:Humans; D020407:Internet; D008484:Medicaid; D006278:Medicare; D009907:Optometry / Q000191:economics*; D012943:Social Security / Q000331:legislation & jurisprudence; D014481:United States; D019131:United States Social Security Administration