Medicare in the United States has several parts: Part A, Part B, and Part D. The Medicare program has a number of components.
Part A is hospital insurance, which covers inpatient hospital care, special nursing equipment, nursing care for the terminally ill, and home health care. Most older Americans do not pay Part A because they already pay Medicare taxes through their work. Patients may be able to purchase Part A coverage if they do not qualify for an exemption from paying Part A premiums, but meet certain conditions.
Part B is Medicare coverage for doctor's visits, outpatient treatment, durable medical equipment, home health services, and other medical services and some disease prevention services. Part B premiums are charged monthly.
Part D is Prescription Drugs, which covers the cost of specific prescription drugs prescribed by a doctor for treatment. Medicare Part D plans are available on a voluntary basis, with an additional monthly premium.
U.S. permanent residents can get Medicare Part A, Part B, and Part D if they meet certain conditions. When a U.S. permanent resident age 65 or older begins receiving Social Security retirement benefits, he or she is automatically enrolled in Part A of Medicare. Early enrollment is possible if you are under age 65 but are otherwise eligible. Generally, seniors with 10 years (40 quarters) or more of total U.S. service are eligible for free Medicare Part A benefits.