Great explanation! I would only add that people with Advantage plans do pay less BUT LOSE CHOICE. One must go to the doctors in their network. I have traditional Medicare with Medigap plan that lets me go where I want. I self-referred to Mayo for lung cancer and got an immediate appointment and surgery set up promptly. I did not have the anguish of waiting to get approval for anything, nor did I need a referral from my primary care doctor. The commercials on TV are outrageous and should not be allowed.