Quick Answer
Medicare Part D plans must cover all or substantially all drugs in six protected classes: antidepressants, antipsychotics, anticonvulsants, antiretrovirals (HIV/AIDS), immunosuppressants for organ transplants, and antineoplastics (cancer). This protection ensures that beneficiaries who rely on specific medications in these categories cannot be denied coverage by their Part D plan, even if the drug is not on the plan's standard formulary.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Medicare Part D (Standalone) | Covered | Must cover all or substantially all drugs in the six protected classes |
| Medicare Advantage with Part D (MAPD) | Covered | Same protected class requirements apply to MA-PD plans |
| Original Medicare (Part A & B) | Not Applicable | Part A and B do not cover outpatient prescription drugs; Part D applies |
| Medicare Supplement (Medigap) | Not Applicable | Medigap does not cover prescription drugs; you need a separate Part D plan |
Understanding Your Coverage Options
The Six Protected Classes
All Medicare Part D plans - including standalone Prescription Drug Plans (PDPs) and Medicare Advantage plans with drug coverage (MA-PDs) - must cover all or substantially all drugs in these six categories: (1) antidepressants, (2) antipsychotics, (3) anticonvulsants, (4) antiretrovirals for HIV/AIDS, (5) immunosuppressants for organ and tissue transplants, and (6) antineoplastics for cancer treatment.
This protection means your plan cannot remove a drug in one of these classes from its formulary mid-year without CMS approval, and cannot require you to try a different drug first (step therapy) for these classes in most circumstances.
What this Means for You
If you take a medication in one of the six protected classes, your Part D plan is required to cover it. If your plan denies coverage, you have the right to appeal. You can also request a formulary exception if your specific drug is not listed, and your plan must give it serious consideration given the protected class rules.
When comparing Part D plans, always verify that your specific medication is on the plan's formulary and at what cost tier. Even within protected classes, cost-sharing (copays and coinsurance) can vary significantly between plans.
Medicare Advantage with Drug Coverage (MA-PD)
Medicare Advantage plans that include prescription drug coverage (MA-PD plans) must follow the same six protected class rules as standalone Part D plans. If you are enrolled in an MA-PD plan, your protected class drugs must be covered.
Frequently Asked Questions
What are the Six Protected Drug Classes in Medicare Part D?
Can My Part D Plan Remove a Protected Class Drug from its Formulary?
What Can I do if My Part D Plan Denies a Protected Class Drug?
Does the Protected Class Rule Apply to Medicare Advantage Drug Plans?
David Haass
CTO & Co-FounderDavid Haass is the Chief Technology Officer and Co-Founder of Elite Insurance Partners and MedicareFAQ.com. He is a member and regular contributor to Forbes Finance Council.
Ashlee Zareczny
ReviewerAshlee Zareczny is a licensed Medicare agent in all 50 states dedicated to educating those eligible for Medicare. She trains agents on CMS compliance guidelines.