Medicare Part D Prescription Denied: How to Appeal

Medicare Part D provides prescription drug coverage through private insurers that contract with CMS. When your Part D plan denies coverage for a medication — because it's not on the formulary, requires Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization, or triggers a step therapy requirement — you have a federally guaranteed right to appeal. Denials are common, but so are reversals for members who know the process.

Why Part D Plans Deny Prescriptions

Formulary exclusion: The drug is not on the plan's list of covered medications.

Prior authorization (PA) required: The plan requires advance approval before covering the drug.

Step therapy (fail-first): The plan requires you to try and fail at one or more alternative medications before it will cover the requested drug.

Quantity limits: The plan limits how much of a drug it will dispense per fill or per month.

Specialty tier placement: The drug is covered but in a very high-cost tier, making it unaffordable.

Non-preferred pharmacy: You used a pharmacy that is not in the plan's preferred network.

Protected Drug Classes

By law, CMS requires Part D plans to cover all or substantially all drugs in six protected classes, with no restriction from prior authorization, step therapy, or formulary exclusion:

1. Antidepressants
2. Antipsychotics
3. Anticonvulsants/antiepileptics
4. Immunosuppressants for transplant patients
5. HIV/AIDS antiretroviral medications
6. Anticancer chemotherapy agents

If your medication falls in one of these categories and is being denied, the plan is almost certainly violating CMS rules.

Step 1: Request a Coverage Determination

Before filing a formal appeal, request a coverage determination from your plan. This is the plan's official decision about whether it will cover the drug for you. You can request:

• Standard coverage determination: Plan must respond within 72 hours for drugs not yet started
• Expedited coverage determination: Plan must respond within 24 hours if a delay would seriously harm your health (your prescriber must support this)

Submit the request in writing with your prescriber's supporting statement explaining why the specific drug is medically necessary and why alternatives are not appropriate.

Step 2: File a Formulary Exception

If the drug is not on the formulary, you can request a formulary exception — asking the plan to cover a non-formulary drug on your behalf. Your prescriber must certify that:

• All formulary alternatives would be less effective for your condition, or
• All formulary alternatives would have adverse effects for you, or
• You have already tried and failed formulary alternatives

Exception requests are processed on the same timeline as coverage determinations (72 hours standard, 24 hours expedited).

Step 3: Request a Tier Exception

If the drug is on the formulary but placed in a high-cost tier, you can request a tier exception — asking the plan to cover it at a lower tier's cost-sharing level. Your prescriber must show that lower-tier alternatives are clinically inappropriate for you.

The Part D Appeals Process

If your coverage determination or exception is denied, appeal:

Level 1: Redetermination by the Plan

File within 60 days of the coverage determination denial.

• Standard decision: 7 days
• Expedited: 72 hours

Level 2: Reconsideration by the Part D IRE

The independent review entity (currently Maximus Federal Services, contracted by CMS) independently reviews your case.

File within 60 days of Level 1 decision.

• Standard: 7 days
• Expedited: 72 hours

If the IRE upholds the denial, the case is automatically escalated to OMHA (Level 3) if it meets the amount-in-controversy threshold.

Level 3: ALJ Hearing at OMHA

File within 60 days of IRE decision. Amount in controversy must be approximately $180 in 2025.

Level 4: Medicare Appeals Council

File within 60 days of ALJ decision.

Level 5: Federal District Court

File within 60 days of MAC decision. Amount in controversy approximately $1,760 in 2025.

Transition Fill Protections

If you are new to a Part D plan (newly enrolling or switching plans during open enrollment), the plan must provide a one-time 30-day supply of any non-formulary drug you were previously taking, to give you time to appeal or transition to a covered alternative. This applies during the first 90 days of enrollment.

If you are in a long-term care facility, your transition protection lasts throughout the year.

Extra Help (Low-Income Subsidy) Protections

If you qualify for the Part D Low-Income Subsidy (LIS/Extra Help), you have additional protections:

• You cannot be denied a covered drug at the point of sale if the plan's records show you are LIS-eligible
• Plans must cover drugs during a transition period even if they were covered under your previous plan
• You may change your Part D plan at any time during the year (not restricted to open enrollment)

What to Do While the Appeal Is Pending

While a standard appeal is in progress:

• Ask your prescriber whether a formulary alternative could work temporarily
• Check if the manufacturer offers a patient assistance program to provide the drug free or at reduced cost while you appeal
• Ask the pharmacy about a partial fill or emergency supply in some states

Fight Back With ClaimBack

Part D denials are frequently reversed, especially when a prescriber provides detailed documentation that alternatives are clinically inadequate. ClaimBack helps you build a compelling appeal request with the right clinical arguments and regulatory citations.

Start your appeal with ClaimBack

Related Reading

• What Is Medical Necessity in Insurance?
• How to Write an Insurance Appeal Letter
• Common Reasons Insurance Claims Are Denied