Medicare Part A is hospital insurance that is free to those who've paid Social Security tax for at least 40 calendar quarters, and Part C is the private insurance alternative to this plan. Part B is medical insurance that covers outpatient services, and Part D provides prescription drug coverage.
Medicare Part A, or Original Medicare, provides inpatient hospital care, stays at skilled nursing facilities and hospice services. It also covers lab tests, specialist visits and some home health care services. Most people receive this coverage free of charge, but those who are ineligible for free services pay $407 per month, as of 2015.
Part C, also called a Medicare Advantage Plan, provides a private insurer alternative to Original Medicare. Costs for these plans vary, depending on features chosen at the time the policy is written.
Medicare Part B provides medical insurance to Medicare beneficiaries. This can be included in a Medicare Advantage Plan or purchased directly from Medicare for $104.90 per month by those who qualify. This portion covers outpatient care, doctor visits, home health care and some preventative services. Durable medical equipment, such as lift chairs, wheel chairs and walkers, are also included in Medicare Part B.
Medicare Part D provides a prescription drug plan to Medicare recipients, and it can be purchased from Medicare or using the Part C option. This plan can be used in conjunction with MediGap policies to reduce the amount of copayment necessary for prescription drug purchases.