Medicare Denied Drug Coverage (Part D Formulary)

What This Means

Your Medicare Part D prescription drug plan denied coverage for a medication. This usually means the drug is not on your plan’s formulary (its list of covered drugs), or the plan requires additional steps before it will cover the drug.

This does not necessarily mean you can’t get the medication covered. Medicare Part D plans have a process for requesting exceptions, and many denials are overturned when your doctor provides supporting documentation.

Why This Happens

• The drug isn’t on your plan’s formulary. Every Part D plan has a formulary — a list of drugs it covers. Your plan may cover an alternative medication but not the specific one prescribed.
• Your plan requires prior authorization. Some drugs need advance approval from your plan before they’re covered. If your doctor prescribed the drug without obtaining prior authorization, the claim will be denied.
• Step therapy requirements weren’t met. Your plan may require you to try a less expensive drug first before it will cover the prescribed medication. If you haven’t tried the required alternative, the claim may be denied.
• Quantity limits apply. Your plan may cover the drug but limit the quantity you can receive in a given time period. If the prescription exceeds that limit, the excess may be denied.
• The drug is excluded from Part D by law. Some drug categories — like those for weight loss, fertility, or cosmetic purposes — are excluded from Part D coverage by federal law.

Should You Appeal?

What To Do Next

1. Check if your drug has new cost protections. Before filing an exception, make sure you aren’t being incorrectly charged:
   • Insulin is capped at $35 per month for all Part D plans (Inflation Reduction Act, effective 2025).
   • Adult vaccines recommended by the CDC (ACIP) are covered at $0 cost-sharing under Part D.
   • If out-of-pocket drug costs are high, ask your plan about the Medicare Prescription Payment Plan — you can spread annual costs into monthly installments.
2. Find out exactly why the drug was denied. Call your Part D plan (the number is on the back of your plan card) and ask for the specific reason. This will tell you whether you need a formulary exception, prior authorization, or something else.
3. Ask your doctor about a formulary exception. If the drug isn’t on the formulary, your doctor can submit an exception request with a statement explaining why the covered alternatives aren’t appropriate for you.
4. Request a tier exception if cost is the issue. If the drug is on the formulary but at a high cost tier, your doctor can request it be covered at a lower tier.
5. Ask about an expedited decision if you need the drug urgently. If waiting could seriously harm your health, your doctor can request an expedited coverage determination, which must be decided within 24 hours.
6. If the exception is denied, file a formal appeal. You have 60 days from the denial notice to request a redetermination from your plan. If your plan upholds the denial, you can escalate to an Independent Review Entity (IRE) for a second review.
7. Ask about a temporary supply. While your exception or appeal is being processed, your plan may be required to provide a temporary supply of the medication to prevent a gap in treatment.

Sources

• CMS: Part D Coverage Determinations
• CMS: Part D Exceptions
• Medicare.gov: Appeals in a Medicare Drug Plan
• KFF: Medicare Advantage Prior Authorization and Denial Data, 2024
• Medicare Interactive: Requesting a Tiering Exception

Frequently Asked Questions