CARC 284 Active

CO-284: Authorization Valid but Not Applicable to Billed Services

TL;DR

Your auth number is valid but does not cover these services. Find the right auth, request retroactive approval, or correct and resubmit. Cannot bill the patient.

Action

Verify & Resubmit

Who Pays

Provider

Appeal

Yes

Patient Impact

None

Disclaimer

This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-284 Mean?

CO-284 means the provider is responsible for the authorization mismatch. The authorization exists but does not apply to the billed services. The provider must find the correct authorization, correct the claim, or obtain retroactive approval. The patient cannot be billed.

CARC 284 indicates that the precertification, authorization, notification, or pre-treatment number provided on the claim may be valid — meaning it exists in the payer's system — but it does not cover the specific services that were billed. The authorization was issued for different procedures, different dates of service, a different provider, or a different scope of treatment than what appears on the claim.

This is a nuanced denial because the provider did obtain authorization, just not the right one for the billed services. Common scenarios include: using an authorization that covers some but not all of the billed procedure codes, submitting a claim for services performed after the authorization expired, billing additional procedures beyond what was originally approved, or simply entering the wrong authorization number due to a clerical error.

The distinction between CARC 284 and a standard no-authorization denial (such as CARC 197) is important: with 284, the payer acknowledges an authorization exists but identifies a mismatch between that authorization and the claim. This typically means the fix is achievable — either locate the correct authorization number, request retroactive authorization, or demonstrate that the existing authorization should cover the billed services.

Common Causes

Cause	Frequency
Authorization does not match billed services The precertification or authorization number provided is valid but was issued for different procedures, dates of service, or providers than what was billed on the claim	Most Common
Services performed exceeded authorized scope The provider performed additional procedures or services beyond what was originally authorized, and the additional services were billed under the same authorization number	Common
Authorization expired before services were rendered The authorization was valid when obtained but the service date falls outside the authorization's effective period	Common
Wrong authorization number submitted A clerical error resulted in the wrong authorization number being placed on the claim, linking it to a different set of authorized services	Common
Incomplete authorization for all billed codes The authorization covered some but not all of the procedure codes billed, and the non-covered codes triggered the denial	Occasional

How to Resolve

Identify the mismatch between the authorization and billed services, then either correct the authorization number, request retroactive approval, or appeal with supporting documentation.

Review the authorization Compare the authorized services, dates, and provider against the claim to identify the specific mismatch.
Locate the correct authorization If the wrong auth number was submitted, find the correct one and resubmit.
Request retroactive auth If no authorization covers the services, request retroactive approval from the payer with medical necessity documentation.
Resubmit with correct auth Submit the corrected claim with the right authorization number.
Appeal if retroactive auth is denied File an appeal with clinical records showing the services were medically necessary.

Appeal Guide

Appeal with the correct authorization number and documentation showing the authorization covers the billed services. If requesting retroactive authorization, include clinical records demonstrating medical necessity and explain why the authorization was not obtained or updated beforehand.

How to Prevent CO-284

Verify authorization numbers match the specific services, dates, and provider before claim submission
Track authorization expiration dates and obtain extensions before services are rendered
Implement authorization verification in your billing system that flags mismatches before submission
Obtain separate authorizations when services expand beyond the original scope

General Prevention

Verify that the authorization number matches the specific services, dates, and provider before submitting the claim
Implement authorization tracking in your billing system that flags mismatches before claim submission
Obtain separate authorizations for services that fall outside the original authorization scope
Train staff to correctly enter authorization numbers and verify them against billed services
Stay informed about payer-specific authorization requirements and update workflows accordingly

Also Filed As

The same CARC 284 may appear with different Group Codes:

PR-284

Related Denial Codes

CO-39 — Services Denied at Pre-Certification CO-61 — Second Surgical Opinion Not Obtained CO-95 — Plan Procedures Not Followed CO-173 — Service/Equipment Not Prescribed by Physician CO-174 — Service Not Prescribed Prior to Delivery

Sources

https://www.mdclarity.com/denial-code/284
https://x12.org/codes/claim-adjustment-reason-codes
Codes maintained by X12. Visit x12.org for official definitions.