Part D is what the original poster is referring to. Part D has that donut hole that many people end up in.
The first year I had Part D, I ended up in the donut hole too. I discussed my medications with my doctor and made some changes to switch to generics where possible. I had to supplement one of my premium medications with a generic AND an OTC medication, but with my doctor's approval, that's what I did. For me, it solved my donut hole problem.
I found this year that I was still on one premium medication and I again got concerned about ending up in the donut hole. I discussed it with my doctor to find out if I really needed it. He agreed to let me stop it (for now) and if my condition worsened, we would revisit the situation and decide if there was another, generic medication that would work rather than using the premium, very expensive medications.
I find that if I'm honest with my doctors about my insurance plan and my needs, they do whatever they can to work with me.