Medicare Advantage Plans, sometimes called "Part C" or "MA Plans," are offered by private companies approved by Medicare. If you join a Medicare Advantage Plan, you still have Medicare. You'll get your Medicare Part A (Hospital Insurance) coverage from the Medicare Advantage Plan and not Original Medicare.
Other benefits MedicareAdvantage Plans may include:
You usually get prescription drug coverage (Part D) through the plan. You can't have prescription drug coverage through both a Medicare Advantage Plan and a Medicare Prescription Drug Plan. So you will have to choose one. You will be dis-enrolled from your Medicare Advantage Plan and returned to Original Medicare if both of these are true: You're in a Medicare Advantage Plan that includes drug coverage You join a Medicare Prescription Drug Plan.