CO-15: The authorization number is missing, invalid, or does not apply to the billed services or provider.
An authorization was expected on this claim, but either none was submitted, the number submitted does not exist in the payer's system, or it was approved for a different service or provider than what was billed.
What the group code means
- CO
- Contractual Obligation. The provider is responsible and the amount cannot be billed to the patient.
Why it fires
- The authorization number field was left blank on the claim
- The authorization number was mistyped or transposed
- The authorization was approved for a different provider, facility, code, or date range than what was actually billed
Corrective actions, ranked
- 1
Locate the correct authorization
Check the original authorization approval for the exact number, provider, and code range it covers.
- 2
Correct and resubmit
If it was a data entry error, add the correct authorization number and resubmit as a corrected claim.
- 3
Request an authorization correction
If the authorization was approved under the wrong provider or code, contact the payer's utilization management department to correct or extend it before resubmitting.
Is it worth appealing
Appeal when a valid authorization did exist for this service but was not properly linked to the claim due to a data or system error.
Retrieved 2026-07-18.
Do not let this happen again
Scrub the claim against NCCI PTP and MUE edits before you submit, free and in your browser.
DenialPath provides billing and administrative guidance based on published CMS and X12 sources. It is not medical advice, not a coverage determination, and not a guarantee of payment. NCCI and MUE edits are republished quarterly and payer policies vary by contract. Always confirm against the payer's own current policy before submitting or appealing.