Glossary
Medicare Part D (Prescription Drug Coverage)
The part of Medicare that helps pay for prescription drugs, including many recommended vaccines.
Part D is the prescription drug side of Medicare. It is offered through private companies approved by Medicare, either as separate drug coverage added to Original Medicare or built into a Medicare Advantage arrangement. Each one keeps a list of the drugs it covers, called a formulary, and that list can change from year to year, which is why the drugs you take are the detail that matters most when you look at what is on offer. Part D carries the extra IRMAA charge for higher earners, and a late enrollment penalty that lasts as long as you keep drug coverage if you go without it for too long and have no other coverage that counts as at least as good. This matters to you because the penalty is calculated from how many months you went without, so it grows the longer the gap runs.