Humana to make sure I absolutely understood what I was getting into. I could have actually found out everything on line, but the phone call made me a lot happier.
Advantage plans do take the place of Medicare A & B. If drug coverage is included, they also replace Part C -- I think that's the drug coverage. My primary care doctor is in my Humana Plan, but not all doctors would be. My friend who pays more for an upgraded Humana plan is that way covered for doctors that would otherwise be out of the network. I just called her, and she pays $15 for a regular office visit, $40 for a specialist, and $65 for an ER visit. Interestingly enough, I have zero copay for a regular office visit, $30 specialist, and the same $65 for ER.
You also want to put in whatever prescription drugs you are currently taking, because I'm guessing that's the big complicating factor.
The other thing to keep in mind is that if something drastically different happens, you can then change plans outside of the normal open enrollment time, but I don't know if say, getting a kidney transplant and now needing to take all the immuno-suppresents would trigger being able to make that change. I know moving would.
It seems complicated, so the best thing to do is take it slowly as you can, find out as much as you can, and compare plans with your personal circumstances.