Fight back on bills

Prior Authorization: How It Works and Whose Job It Is

What prior authorization is, why it is mostly your provider's task, how to confirm one exists before care, and the federal deadlines tightening in 2026.

Current as of August 31, 2026 Fight back on bills

Prior authorization is approval from your health plan that may be required before you get a service or fill a prescription, in order for the plan to cover it. No approval, no coverage - even when the service is medically appropriate and clearly a covered benefit. It is the one step in the billing chain where a missing piece of paperwork can turn a covered service into a bill with your name on it. So it pays to know exactly whose job it is and how to verify it happened.

What typically needs prior authorization

Every plan keeps its own list, and the list changes. Services that commonly require it include:

Advanced imaging: MRI, CT, PET scans
Planned surgeries and non-emergency hospital admissions
Specialty medications and infusions
Durable medical equipment: wheelchairs, CPAP machines, home oxygen
Home health services and skilled nursing stays
Physical therapy beyond an initial number of visits

Emergency care is the standing exception. Under the No Surprises Act, most emergency services are protected from surprise billing even when you had no approval beforehand - see what the No Surprises Act covers.

The only list that matters is your plan’s. The plan documents say which services need authorization, and the member services line can tell you for a specific procedure code.

Whose job it is

Obtaining prior authorization is generally the ordering provider’s task. The office that schedules your MRI submits the request, supplies the clinical notes, and answers the plan’s questions. They do this constantly. You could not submit most of it yourself if you wanted to, because the plan wants clinical documentation only the provider has.

But here is the asymmetry that matters: the provider does the work, and you absorb the consequences if it does not get done. A denied claim for lack of authorization lands on you first. So treat the provider’s task as something you verify, not something you assume.

One more wrinkle: authorization is not a promise of payment. It usually means the plan agrees the service is medically necessary under its rules. The claim can still be denied later for other reasons - eligibility, coding, network status. Which is why the in-network question is a separate call you also make before a scheduled service.

How to confirm authorization exists before your service

Do this for any scheduled service that might need it. Two calls, ten minutes total.

Call 1 - the provider’s office, a week or more before the service:

I’m scheduled for [service] on [date]. Can you confirm whether my plan requires prior authorization for this, and if so, that it has been approved? I’d like the authorization number.

Call 2 - your plan’s member services line:

I’m calling to confirm a prior authorization is on file. My member ID is [ID]. The service is [service] with [provider] on [date]. Can you give me the authorization number, the approval date, what exactly it covers, and its expiration date? And can I have a reference number for this call?

Write down both numbers, the date, and the name of each person you spoke with. If the two calls disagree - the office says approved, the plan has nothing on file - stop and resolve it before the service happens, not after. A prior authorization confirmation letter you can adapt is in the templates library, and calling your insurance covers how to get through the phone tree with your sanity intact.

Worked example: you are scheduled for a knee MRI on March 12. On March 3 the imaging center says authorization was submitted. On March 4 the plan says the request is pending with no decision. That gap is normal, but it is now your calendar item. Call the plan again March 9. If it is still pending, ask the imaging center to escalate or move the date. An MRI performed one day before its authorization is approved is a denied claim.

Retroactive denials and how to fight them

Sometimes the claim is denied after the service: the plan says no authorization was obtained, or the authorization did not cover what was actually done. Do not pay this bill reflexively. Work through it:

Establish what happened. Get the denial reason from your EOB - here is how to read it. Was authorization never requested, requested and denied, or approved but mismatched to the billed code?
If the provider was supposed to obtain it and did not, say so, in writing, to the provider. Many plan contracts make a missed authorization the provider’s financial problem, not the patient’s. Ask the provider to resolve the claim with the plan or write off the charge.
If you confirmed authorization before the service, you are in a strong position. Send the plan the authorization number and your call reference number from before the service.
Appeal. A retroactive authorization denial is appealable like any other denial. Follow the process in how to appeal a denied claim and check your deadline with the appeal deadline tool.

The rules are tightening in 2026 and 2027

A federal rule finalized by CMS (CMS-0057-F) is phasing in now. It applies to Medicare Advantage plans, state Medicaid and CHIP programs, Medicaid and CHIP managed care plans, and marketplace plans on the federal exchange. Generally beginning January 1, 2026, with some requirements varying by payer type:

Faster decisions: covered payers (excluding federal marketplace plans for this provision) must send prior authorization decisions within 72 hours for expedited requests and 7 calendar days for standard requests.
Specific denial reasons: beginning in 2026, denials must state a specific reason, whatever channel the request came through.
Public metrics: payers must post prior authorization statistics on their websites annually, with the first set due by March 31, 2026.
Electronic processing: by January 1, 2027, these payers must run prior authorization through standardized APIs, which is plumbing you will never see but should shrink the fax-and-wait delays.

The rule excludes prior authorization for drugs, and employer plans are not covered by it. But if you are on Medicare Advantage or Medicaid and a standard request has been sitting for three weeks, the plan is now outside the federal timeframe - say so when you call.

Sources

Figures and rules on this page are current as of August 31, 2026. Dollar limits and deadlines change - check the linked source before you rely on a number.

Support this site

This site is free, has no paywall, and takes no money from hospitals, insurers, or billing companies. If it helped, a coffee keeps it going.

Buy us a coffee