CO-15: Missing or Invalid Authorization
The submitted authorization number is missing, incomplete, or invalid. The service required prior authorization that was not obtained or was not properly documented on the claim.
Why Claims Get Denied with CO-15
Denial code CO-15 is triggered when the submitted authorization number is missing, incomplete, or invalid. the service required prior authorization that was not obtained or was not properly documented on the claim. Understanding the root causes helps prevent future denials and strengthens your appeal when one occurs.
Prior authorization was not obtained before the service was rendered
Authorization number was not included on the claim form
Authorization number was entered incorrectly or transposed
Authorization expired before the date of service
Service performed differs from what was authorised
How to Appeal CO-15
If authorization was obtained, resubmit with the correct authorization number and a copy of the authorization letter. If authorization was not obtained, check whether the payer allows retroactive authorization requests and file within the allowed timeframe. Document any emergency circumstances that prevented prior authorization.
Documentation Required for Appeal
A successful appeal of CO-15 requires thorough documentation. Gather these items before drafting your appeal letter:
Copy of prior authorization approval letter
Correct authorization reference number
Documentation of emergency circumstances (if applicable)
Retroactive authorization request (if allowed by payer)
How to Prevent CO-15 Denials
Verify authorization requirements for all procedures before scheduling. Build authorization tracking into your practice workflow. Set calendar reminders for authorization expiration dates.
Stop Fighting CO-15 Denials Manually
RediClaim generates payer-specific appeal letters for CO-15 denials in under 60 seconds, complete with the clinical arguments and documentation references that win reversals.