What is prior authorization?

The short answer

Prior authorization (also called pre-authorization, pre-certification, or “prior auth,” usually muttered) is a rule in many health plans: before the plan will pay for certain tests, drugs, procedures or equipment, your clinician has to ask permission and prove the care is medically necessary. Think of it as a hall pass, except the hall monitor has never met you and works for the company paying the bill.

If the plan says yes, your benefits cover it. If it says no, you can still get the care, you just might pay for it yourself, and your clinician can appeal. Appealing is a lot like arguing with a vending machine, except sometimes the vending machine changes its mind.

What needs a permission slip

It varies by plan, but the usual suspects are advanced imaging (MRI, CT, PET), specialty and brand-name drugs, planned surgeries and hospital stays, durable medical equipment, home health, and some physical therapy. Emergency care should not require prior authorization. Even insurers agree you shouldn't have to fax a form while having a heart attack.

How it works, in theory

Your clinician's office submits a request with your diagnosis, the planned care and supporting notes. The plan approves it, denies it, or asks for more information, which is insurance for “please send the same notes again.” If it's denied, your clinician can request a “peer-to-peer” call with a doctor who works for the plan, then file a formal appeal.

In practice it involves fax machines more often than anyone in the 21st century should admit, and hold music long enough to count as a residency.

Why doctors make that face when you say it

Insurers say prior authorization stops unnecessary and unsafe care. Physicians say it delays treatment and eats hours of staff time every week; American Medical Association surveys consistently find that most physicians believe it sometimes leads patients to give up on treatment altogether. It's one of the most-cited causes of administrative burden and burnout, which is a polite way of saying it's why your doctor's eye twitches.

What changed in 2026 (yes, something improved)

A federal rule from the Centers for Medicare & Medicaid Services (CMS-0057-F) now requires Medicare Advantage, Medicaid, CHIP and federal Marketplace plans to decide prior authorization requests within 72 hours for urgent requests and 7 calendar days for standard ones, and to give a specific reason when they say no. “Because” is no longer a reason. Employer plans aren't covered by that rule, though many states have their own “gold card” and timeline laws.

How to fight back without a fax machine

Ask your clinician's office whether the test or drug needs prior authorization and whether it's been submitted. Get the reference number and guard it like a lottery ticket. Call your plan to check the status. If it's denied, ask for the denial and the reason in writing, ask your clinician about a peer-to-peer review, and file an appeal: many denials are overturned on appeal, which tells you something about the first answer.