CO-197 Denial Code: Prior Authorization Absent
The CO-197 denial code means the service required precertification, prior authorization, or advance notification and the payer has no record of one. Unlike CO-15 (an authorization exists but does not match), CO-197 says the approval simply is not there. Because the CO group makes this a provider write-off, the practical paths are retroactive authorization, appeal with good cause, or process fixes to stop the next one.
Common Causes
- The service required prior authorization and none was requested before it was performed
- Authorization was obtained but never recorded or transmitted on the claim, and the payer could not match it
- The scheduled procedure changed in the operating room to one that was not on the authorization
- Payer rules changed - a service that previously needed no authorization now does
- Urgent or emergent services performed before authorization, without the payer's required notification afterward
How to Fix CO-197
- Confirm whether authorization truly was required for that code, plan, and setting - payer portals list auth-required services
- If an authorization exists, resubmit the claim with the authorization number so the payer can match it
- If none exists, request a retroactive authorization - many payers allow retro-auth within a defined window, especially for urgent services
- Appeal with documentation when circumstances justify the gap: emergency care, payer misinformation at eligibility check, or procedure changes driven by intraoperative findings
- Prevent repeats with a scheduling-stage authorization checklist tied to current payer auth-required lists
Frequently Asked Questions
CO-197 means the precertification, prior authorization, or notification the service required is absent - the payer has no record that approval was obtained before (or, where allowed, after) the service was performed.
Often, yes. If an authorization existed, resubmit with the number. If not, request retroactive authorization where the payer allows it, or appeal with documentation of emergency circumstances, payer error, or intraoperative changes to the planned procedure.
No - the CO group code assigns the amount as a contractual write-off. Obtaining authorization is the provider's responsibility under network contracts, so the balance cannot simply be shifted to the patient.
Related Denial Codes
Related Resources
Claim adjustment reason codes and remittance advice remark codes are standardized code sets maintained by X12. The explanations on this page are written in our own words for educational purposes, based on public CMS and Medicare contractor documentation. Payer policies vary - always confirm handling with the specific payer's guidance and your contracts.