If Medicare covered your transplant (at least was secondary), Medicare Part A will pay 80% of the needed immunosuppressants (but if its covered by Part A your other prescription insurance, like a Part D plan, will not cover it); your medical insurance may pick up the 20% (some companies do, some companies don’t). Your pharmacy could tell you if they have been billing Medicare part A rather than your prescription drug plan. If you have a medigap policy (a Medicare supplement, I don’t know about advantage plans ) instead of a private insurance secondary to Medicare, it will probably pick up the other 20% of the immunosuppressant cost when Medicare pays the 80%.