What is Medicare?
Medicare is a federal health insurance program for:
- People ages 65 and older
- People younger than age 65 with certain disabilities
- People of all ages with end-stage renal disease or permanent kidney failure
Medicare has three main parts:
Medicare Part A—Hospital Insurance
Medicare Part A helps cover your inpatient hospital care, including care received at critical access hospitals and skilled nursing facilities. Under certain conditions it even covers hospice care 
and some home health care.
When you enroll in Original Medicare , you are automatically enrolled in Part A (enrollment in Part B is optional). Most people don't pay a premium for Part A because they or their spouse already paid for it through payroll taxes while working. If you do not qualify for premium-free Part A, you can purchase it and have it automatically deducted from your Social Security checks.
Medicare Part B—Medical Insurance
Medicare Part B helps cover your doctors' services and outpatient hospital care . It also helps cover some medical services that Medicare Part A doesn't cover, such as physical and occupational therapies, and preventive services like mammography and prostate screenings.
Enrollment in Medicare Part B is optional. However, to be eligible for a Medicare supplement or Medicare Advantage plan , you must continue to pay your Part B premium if not otherwise paid for under Medicaid or by another third party.
Medicare Part D—Prescription Coverage
Introduced in 2006, Medicare Part D is a voluntary prescription drug program available to help people with Medicare pay a portion (or all) of the cost of their prescription medications. Part D coverage, like Original Medicare, can protect you from high and unexpected costs, so plan ahead. Even if you don't take any prescriptions today, you may need them in years to come.
Medicare Part D plans can only be purchased through a private insurance company like Blue Cross Blue Shield of Massachusetts. To get Medicare Part D prescription coverage, you can purchase a standalone Part D prescription plan or you can enroll in a Medicare Advantage health plan with Part D prescription coverage.
