Who's eligible for Medicare Part C coverage -- and what types of plans are included?

If you're eligible for Medicare Part A and Part B, you can join a Medicare Part C plan instead. To join one, though, the plan's insurance company must be offering it in the region -- usually a county or group of counties -- where you live. And that particular plan must be accepting new enrollees.

Medicare Part C plans come in two basic types:

• Managed care
• Fee-for-service

Medicare Part C managed care plans: There are several kinds of managed care plans, but they all operate under the same basic rule: You get full coverage only if you see a healthcare provider who is a member of the plan's "network." The most common, least expensive, but most restrictive Medicare Part C managed care plans are health maintenance organizations (HMOs). There are also Medicare Part C preferred provider organizations (PPOs) and Part C HMOs with a point-of-service (POS) option that add certain variations to basic HMO rules.

Medicare Part C fee-for-service plans: A Medicare Part C fee-for-service plan works differently than a managed care plan, without the same "network" limitation of managed care. Instead, a Medicare Part C fee-for-service plan allows you to see any provider, but only if that provider accepts the plan's restrictions on the particular medical service and accepts the amount the plan is willing to pay for that service.