CO-197: Precertification/authorization/notification/pre-treatment absent.
The service required prior authorization or notification to the payer before it was performed, and the payer has no record that this was obtained. The claim is denied for a process failure, independent of whether the service itself was medically appropriate.
What the group code means
- CO
- Contractual Obligation. The provider is responsible and the amount cannot be billed to the patient.
Why it fires
- No prior authorization was requested before a service that requires it
- Authorization was requested but not approved before the date of service
- Authorization was obtained under a different provider, facility, or code than what was billed
Corrective actions, ranked
- 1
Search for the authorization
Check if an authorization number exists in the system under a different reference, provider, or date range before assuming none exists.
- 2
Request retro-authorization
Contact the payer to request a retroactive authorization or peer-to-peer review, especially for urgent or emergent services.
- 3
Fix the front-end process
If this is recurring, add a hard stop in scheduling or registration requiring auth verification before the service is rendered.
Is it worth appealing
Appeal is worth filing when the service was urgent or emergent, waiving the auth requirement, or when proof exists that authorization was actually obtained but not linked to the claim correctly.
Other denial codes to check
Codes that share a remark code with this one, or that are reported under the same group code.
- CO-45Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.
- CO-97The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated.
- CO-16Claim/service lacks information or has submission/billing error(s).
- CO-11The diagnosis is inconsistent with the procedure.
- OA-18Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)
- CO-29The time limit for filing has expired.
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.
Denial7 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.