How Prior Authorization Works and What to Do When You Hit It

By Dr. Alan Whitfield, MD · Reviewed and updated on June 1, 2026

This article is educational and is not medical advice. For care decisions, talk with a licensed clinician; for coverage decisions, review your plan documents and speak with your insurer.

Understanding how prior authorization works can spare you days of frustration when a pharmacy says your medication “needs approval” or a scan is put on hold. Prior authorization is a process where your insurer requires sign-off before it will cover certain drugs, tests, or procedures. It is meant to confirm a service is appropriate and covered — but it can also delay care, so knowing the steps helps you move things along.

What prior authorization is for

Insurers use prior authorization for higher-cost medications, advanced imaging, some procedures, and brand-name drugs that have generic alternatives. The goal, as described in consumer materials from the Centers for Medicare & Medicaid Services, is to verify medical necessity and steer toward covered, cost-effective options. Whether that goal is always met is debated, but the mechanics are consistent across plans.

How prior authorization works, step by step

Knowing how prior authorization works in sequence removes a lot of the mystery:

• Your clinician prescribes a drug or orders a service.
• The pharmacy or facility discovers the plan requires authorization.
• Your clinician’s office submits clinical information to the insurer.
• The insurer approves, denies, or requests more information, usually within a set number of days.
• If approved, coverage proceeds; if denied, you can appeal.

Why you might get a denial

Denials often come down to fixable reasons: the plan wants you to try a lower-cost option first (called step therapy), paperwork was incomplete, or a code did not match. A denial is not the end of the road. The federal appeals rights let you request an internal review and, if needed, an independent external review.

How to move it along faster

You are not powerless while you wait. Call your clinician’s office to confirm they have submitted the request, ask the insurer for the expected decision timeframe, and ask whether an expedited review is available if a delay could harm your health. Keep a log of names and dates. If a medication is urgent, ask your prescriber about a short bridge supply while the review is pending.

The appeal, if it comes to that

If the request is denied, you can appeal. Your clinician can submit a letter of medical necessity explaining why the specific drug or service is appropriate for you. Many appeals succeed, especially when the clinical reasoning is documented. Reliable background on coverage and appeals is published by KFF. For understanding the denial notice itself, see how to read an explanation of benefits.

How to reduce surprises next time

When starting a new medication, ask your prescriber whether it is likely to need authorization and whether a covered alternative exists. Checking your plan’s formulary in advance — and seeing how to lower prescription costs — can prevent the delay entirely. If you are choosing a plan, this is one more reason to read the fine print, as covered in health insurance for self employed options.

Authorization rules, timeframes, and appeal rights vary by plan and state and change over time — always confirm current details with your insurer.

When to talk to your doctor or insurer

If a delay is affecting your health, tell your clinician’s office directly and ask about expedited review; for coverage specifics, call the number on your insurance card. The most useful step is to ask early, document everything, and appeal when a denial does not match your clinician’s judgment.

Written by Dr. Alan Whitfield, MD, a physician-writer focused on patient education.