Medicare Part D Prior Authorization: What to Do When a Drug Is Denied

When Prior Authorization Blocks the Pharmacy Counter

Your parent hands over a prescription and the pharmacist says the plan requires prior authorization. The drug isn't denied permanently — the plan wants clinical proof that it's medically necessary before agreeing to cover it. But until that proof arrives, your parent walks out without the medication.

Prior authorization is one of the three utilization management tools Part D plans use to control costs (alongside step therapy and quantity limits). For caregivers, the practical concern isn't why the plan requires it — it's how fast you can get approval.

The Two Timelines

Standard Request: 72 Hours

The prescribing doctor submits a clinical statement to the plan's pharmacy coverage department explaining why this specific drug is needed. The plan has 72 hours from receiving that statement to issue a decision. In practice, the bottleneck is the doctor's office, not the plan. Getting the physician to fax or electronically submit the supporting documentation can take days if the office is backlogged.

Expedited Request: 24 Hours

If the prescribing physician certifies that waiting 72 hours would seriously jeopardize the parent's life, health, or ability to regain function, the plan must decide within 24 hours. An expedited request requires this physician certification.

This matters most after hospital discharge, when your parent may be sent home on a new medication regimen and hitting a prior auth wall means a gap in treatment.

What the Doctor's Statement Needs to Include

A prior authorization request succeeds or fails on the supporting clinical documentation. The prescribing physician's statement must establish:

1. Medical necessity: Why this specific drug is required for the parent's condition.
2. Alternatives tried and failed: Evidence that covered formulary alternatives are medically inappropriate, have been clinically ineffective, or caused documented adverse reactions.
3. Clinical consequences of delay: What happens to the patient if this medication isn't started or continued promptly.

Vague statements ("patient needs this medication") may not establish the exception. A specific clinical history ("patient developed severe GI bleeding on Drug X, the Tier 2 alternative, requiring hospitalization on [date]") gives the plan information it needs to evaluate the request.

If the Prior Auth Is Denied

A denied prior authorization isn't the end. You have the right to request a formal Coverage Determination from the plan — essentially asking them to make an exception to the formulary restriction. Use Form CMS-10146 or write a detailed letter to the plan's coverage department.

If that's denied too, you can appeal through the five-level Medicare appeals process. The redetermination (second level) must be decided within 7 days for standard requests or 72 hours for expedited ones.

The Transition Supply Safety Net

If your parent just enrolled in a new Part D plan and their current medication requires prior authorization under the new plan, federal rules require a temporary transition fill. The plan must provide at least one temporary 30-day supply of the medication while the prior authorization is processed.

This transition supply is temporary; use it while the prior authorization is resolved. After the transition supply, the prior authorization must be resolved or the medication switches to out-of-pocket cost.

What Caregivers Should Do Right Now

If a prior auth is likely based on the plan's formulary restrictions — you can check this during plan comparison season by looking for "PA" flags next to drugs — get ahead of it. Contact the prescribing doctor's office before the plan year starts and ask them to submit the prior authorization request proactively. Some plans accept pre-enrollment PA requests during December that take effect January 1.

Our Medicare Part D guide includes a prior authorization tracking worksheet and a sample physician statement template designed for the specific format plans expect.

See more United States guides →