Part A is Hospital Insurance and covers cost associated with confinement in a hospital or skilled nursing facility. (see Medicare Part A)
Medicare Advantage Plans are health plan options that are approved by Medicare but run by private companies. They are part of the Medicare Program, and sometimes called "Part C." When you join a Medicare Advantage Plan, you are still in Medicare. (see Medicare Part C) With Medicare Advantage Plans:
Why Do You Need Health Insurance?
Today, health care costs are high, and getting higher. Who will pay your bills if you have a serious accident or a major illness? You buy health insurance for the same reason you buy other kinds of insurance, to protect yourself financially. With health insurance, you protect yourself and your family in case you need medical care that could be very expensive. You can't predict what your medical bills will be. In a good year, your costs may be low. But if you become ill, your bills could be very high. If you have insurance, many of your costs are covered by a third-party payer, not by you. A third-party payer can be an insurance company or, in some cases, it can be your employer.