In Medicare term, Part C=MA, Plan is for Medigap A, G, N etc

Medicare program is funded through Social Security Administration (SSA), and the major funding is from salary deduction while a smaller portion is funded by the Medicare premium such as Part B. When you sign up Medicare (at 65) through SSA, you get a Medicare # and you either pay your premium to Medicare or get it deducted from your SSB check. Then the fun part begins...

Option:

1. Medicare (80% government program, 20% Medigap or Medicare Supplement + Part D drug plan by private providers). Each private provider Plan (like A, B, C, G, N) Part D has different premiums to choose from (but no $0 plan).

2. Medicare Advantage or Part C (100% private provider under Medicare guidance, covering most of the above items plus some additional benifit like dental, vision, hearing and/or fitness program). All private plans have a different premium inculding the popular $0 plans.

So the key difference is you either stay within oringinal Medicare (+Medigap+Part D by private providers) or with a private provider for everything under one roof. In general, you choose original Medicare for flexibility/option while MA for cost/simplicity. It's like pay upfrount or pay as your go.