What an authorization denial is
A prior authorization denial means the payer expected an approval before the service and did not find one linked to the claim. It is one of the most common and most preventable reasons a clean-looking claim comes back unpaid. This guide explains what these denials are, how to read the codes on the remittance, how to work them, and how to keep them from happening again.
Note the distinction. An authorization denial is about permission: the approval was missing, expired, did not match the claim, or was requested from the wrong entity. A medical necessity denial is about the payer's judgment: the claim was processed and the payer decided the service was not medically necessary under its policy. The fix for each is different, which is why reading the remittance matters.
The codes on the remittance
Denied claims carry claim adjustment reason codes (CARCs) and remark codes that explain the decision. For authorization problems, these are the codes you will see most often.
| Code | What it means | Where responsibility usually falls |
|---|---|---|
| CO-197 | Precertification or authorization absent; the payer had no required approval on file. | Provider, under most network contracts |
| PR-197 | Precertification or authorization absent, assigned to the patient. | Patient, per the remittance group code |
| PR-242 | Services not provided by a network or primary care provider, often an out-of-network or referral problem. | Patient, per the remittance group code |
| PR-40 | Charges do not meet qualifications for emergent or urgent care. | Patient, per the remittance group code |
The X12 descriptor for CARC 197 is "Precertification/authorization/notification/pre-treatment absent." Our article on the CO-197 denial code goes deeper into its triggers, remark code pairings and the correction-vs-appeal decision. The group code in front of the number matters: CO places the amount on the provider, while PR places it on the patient under the contract. Read both before deciding what to do.
What causes these denials
The causes behind authorization denials repeat across specialties. Once you know the pattern, you can usually spot the cause from the claim and the approval side by side.
- No authorization was requested. The front desk did not know the service required one, often because the payer's list changed or the patient changed plans.
- The authorization existed but never reached the claim. The number was obtained but not entered in the authorization field, or it did not link on the payer's side.
- Mismatch. The approved CPT or HCPCS code, units, rendering provider, facility or date range differs from the claim.
- Visits or units exhausted. Therapy and behavioral health approvals often cover a set number of sessions. Claims after the last approved visit deny.
- Expired authorization. Care continued past the end date without an extension.
- Wrong entity. The authorization was requested from the health plan when a delegated vendor or behavioral health carve-out manages it, or the reverse.
Peer-to-peer review and appeal steps
When a denial lands, work it in order. Skip a step and you will appeal something that needed a corrected claim, or correct something that needed an appeal.
First, confirm whether the service actually required authorization for this patient's plan on this date, using the payer's current authorization list rather than an old copy. Second, search your records and the payer portal for any authorization covering the date of service, including ones obtained by a referring provider or the facility. Third, if one exists, compare it against the claim: codes, units, provider, location and dates. Fix whatever does not match.
If the authorization existed and was valid, send a corrected claim with the number in the right field. If no authorization existed, ask the payer whether it accepts retroactive authorization requests for this service. If it does not, and you believe the denial is wrong, file an appeal before the payer's deadline. Record the root cause either way.
| Step | What to send |
|---|---|
| Peer-to-peer review | A clinician-to-clinician call, requested within the payer's window, with the chart and relevant guidelines ready |
| Appeal letter | A short letter stating exactly which situation applies: no authorization was required, the approval existed, the service was an emergency, or a retroactive approval was obtained |
| Documentation packet | The authorization approval, call reference numbers, the payer's authorization list for that date, and the clinical note supporting the service |
Frame appeals honestly. No appeal has a guaranteed outcome. Outcomes depend on the payer, the contract and the documentation, so the realistic goal is to work every eligible denial on time and track the results. Our prior authorization services handle both the up-front approvals and the back-end denial work.
A prevention workflow for your front desk
Authorization denials are best stopped days before the visit, at scheduling and eligibility checks, not after the remittance arrives.
- Verify authorization requirements during insurance checks for every new patient, new plan year and new service.
- Keep a current authorization list for your top payers, with the source document and the date you last checked it.
- Track every approval with its approved codes, units, provider, location and dates, and alert staff when a patient is close to the last approved visit or the end date.
- Request extensions before approvals run out, with progress notes ready.
- Make the authorization number a required field before a claim can be released.
- Check whether a provider holds a prior authorization exemption under Texas's gold card law. Our Texas gold card guide explains how it works.
Help with authorization denials
If authorization denials are eating into your collections, Fastora can take over both ends: tracking approvals up front and working denials on the back end, with certified billing professionals deciding between correction, retroactive authorization and appeal. See our denial management service, or request a free billing assessment where we review your denied claims and explain the root causes.