According to SSA.GOV,  “Part A (hospital insurance): Hospital insurance helps pay for inpatient care in a hospital or skilled nursing facility (following a hospital stay), some home health care and hospice care. Part B (medical insurance): Medical insurance helps pay for doctors’ services and many other medical services and supplies that hospital insurance does not cover. Part C (Medicare Advantage plans): If you have Medicare Parts A and B, you can join a Medicare Advantage plan. Medicare Advantage plans are offered by private companies and approved by Medicare. These plans generally help you pay the medical costs not covered by Medicare Part A and B. Part D (prescription drug coverage): Prescription drug coverage helps pay for medications doctors prescribe for treatment.”