Besides original Medicare, which includes Parts A and B, there are also several Medicare Advantage plans to choose from, also known as Part C, according to Medicare.gov. Additionally, Part D provides prescription drug coverage.
Medicare Advantage plans include HMOs, PPOs, Private Fee-for-Service and Special Needs plans, notes Medicare.gov. For the most part, HMOs only cover services from doctors and hospitals that are part of the plan's network of providers, and recipients must get a referral to see a specialist. PPOs also cover some out-of-network expenses without a referral or emergency. Private Fee-for-Service plans pay a set amount for each type of service, while the recipient pays the remainder of the bill. Special Needs plans are covered by the other types of providers, such as HMOs and PPOs, but enrollment is limited to a certain segment of people.