Part A
Part A is part of traditional Medicare and covers inpatient hospital insurance.
Part B
Part B is part of traditional Medicare and covers outpatient medical treatments.
Part C
Part C is made of Medicare Advantage Plans and combines the benefits of Part A and B, and may also include prescription drugs, dental, vision, hearing, and wellness services.
Part D
Part D deals with prescription drug coverage and provides lower cost-sharing for in-network and preferred pharmacies.