The authorization number is missing, invalid, or does not apply to the billed services or provider

Why this happens on dental claims

• Orthodontic or oral surgery authorizations approved for one CDT code but billed under another after the treatment plan changed
• Authorization obtained under one provider or location NPI while the claim was billed under another, common after associates join or a second location opens
• Pre-treatment estimate numbers entered in the authorization field when the payer issues a separate number for the actual authorization

How to appeal CO-15

1. Locate the original authorization letter or portal record and compare its number, approved codes, provider, and validity dates against the claim
2. If the number was mistyped or omitted, resubmit a corrected claim with the exact authorization number
3. If the service changed after approval, request an updated or retroactive authorization citing the clinical reason for the change
4. Escalate to a formal appeal enclosing the authorization document itself when the payer's system fails to match a valid approval

How to prevent it

• Store authorization numbers, approved codes, and expiration dates as structured PMS fields, not free-text notes
• Re-verify the authorization whenever the treatment plan changes, before the work is done