A: Medicare has four Parts:
Part A: Hospital care: Covers care you receive in inpatient hospital settings.
Part B: Medical care : Covers your doctor visits, lab work, durable medical equipment, outpatient services, etc.
Together, Parts A and B are sometimes called Original Medicare or Traditional Medicare.
Part C (Medicare Advantage or Medicare Health Plans): Optional, privately-run health plans that substitute for Original Medicare as long as you have the plan, and sometimes include Part D. These plans must provide the same benefits as Original Medicare, but may provide them in a different way (such as with different copays or coinsurance). If you leave a Medicare Advantage plan, you return to Original Medicare.
Part D: Optional, privately-run prescription drug plans. These may be stand-alone plans covering prescriptions only, or be included in a Medicare Advantage plan.