Medicare Advantage Plans are also known as Part C. They combine Parts A, B, & usually Part D all in one plan. ​You must live in the Service area (which is usually determined by the county you live in). If you choose a Medicare Advantage plan, you will not lose your Original Medicare benefits. However, an insurance company can add benefits to it. A Medicare Advantage Plan is not a Medicare Supplement nor can you have both an Advantage Plan and a Medicare Supplement. Most Advantage Plans have co-pays, coinsurance, and network doctors and hospitals, but the premiums are usually much lower than a supplement.