Part A:

Hospital Insurance helps cover inpatient care in hospitals, skilled nursing facility (SNF) care, hospice care, and home health care. A general rule of thumb for Part A coverage is called the "Two-Midnight rule". If a doctor admits a Medicare enrollee as an inpatient with the expectation that the patient will require hospital care across two midnights, Medicare Part A will be appropriate for coverage. Medicare Part A will cover hospital inpatient stays (consecutive or intermittent) up to 90 days. The first 60 days would all be covered in full by Medicare after deductible is met for the benefit period, days 61-90 will require a daily coinsurance. In most cases, enrollees are automatically enrolled in premium-free Part A if they have worked and paid Social Security taxes for at least 40 calendar quarters (10 years).

Part B:

Medical Insurance to cover products and services that are not covered by Part A, generally on an outpatient basis. The two types of services that Part B covers are medically necessary services and preventive services. Medically necessary services are those that are required to diagnose or treat a medical condition. Preventive services are services that can prevent illness or discover it at an early stage, when treatment would be most effective. These two covered types of services are extensive and include many outpatient services. After the deductible is met, Part B will pay for 80% of the Medicare-approved services and the patient typically pays the remaining 20%. Part B, unlike Part A, requires a monthly premium. Part A and Part B make up what is called Original Medicare.

Part C:

Medicare Advantage plans
See the Medicare Advantage plans page here.

Part D:

Medicare Prescription Drug plans subsidizes the cost of prescription drugs for Medicare beneficiaries. To qualify for a Medicare Part D Prescription Drug plan, prospective beneficiaries must already be signed up for benefits under Medicare Part A and/or Part B. Medicare Part D Prescription Drug plans are offered by Medicare-approved private insurance companies. The monthly premium of each Medicare Part D Prescription Drug plan may differ. Medicare Prescription Drug plans have a formulary which is a list of covered drugs. The formulary may change at any time. Individuals will receive notice from their plan when necessary.