CO-197 Denial Code: Authorization Absent and How to Appeal

The CO-197 denial code means precertification, authorization, notification, or pre-treatment was absent — the payer required approval before the service and did not have one on file. The CO (Contractual Obligation) group usually makes it a provider write-off you cannot bill the patient. CO-197 is appealable when authorization existed, could have been obtained retroactively, or was not actually required.

What is the CO-197 denial code? CO-197 is a Claim Adjustment Reason Code (CARC) indicating the required precertification, authorization, notification, or pre-treatment was absent, so the payer denied the service for lack of prior approval.

Undeny's Take

CO-197 is where behavioral health bleeds the most avoidable revenue, because authorization rules cluster exactly where the dollars are: psychological testing, intensive outpatient and higher levels of care, and extended sessions. The reflexive appeal rarely works — but two things do. First, the retro-authorization window: many payers grant authorization after the fact within a short period, so move immediately. Second, prove the auth wasn't required, or was on file under a different number, before you argue medical necessity. The durable fix is an authorization tracker tied to the services your payers actually gate, checked before the patient is seen.

What CO-197 Means

CO-197 corresponds to X12 code 197: "Precertification/authorization/notification/pre-treatment absent." The payer's policy required prior approval for the service, and none was recorded when the claim was adjudicated. The CO group code typically makes the denied amount a contractual obligation — you cannot bill the patient for failing to obtain an authorization that was the provider's responsibility.

Why CO-197 Happens

The service required prior authorization and none was obtained before treatment.
An authorization existed but was not referenced or was reported with the wrong number.
The authorization expired, ran out of approved units, or did not cover the billed code.
A notification the plan required (for example, of admission or a level-of-care change) was not made in time.

How to Fix and Appeal a CO-197

Check whether an authorization actually existed and was simply not attached or was reported incorrectly.
Confirm whether the service truly required prior authorization under the patient's plan.
Request a retroactive authorization immediately if the payer allows one within its post-service window.
File the appeal with the authorization record or medical-necessity documentation, or draft it with the appeal generator.

Related Codes

CO-197 sits near other coverage and non-covered denials. CO-96 means non-covered charges, sometimes for the same authorization reason named in a remark code. PR-204 means the service is not covered under the benefit plan and the patient owes. Browse the full set under denial codes.

Frequently Asked Questions

What does CO-197 mean?

CO-197 means the required precertification, authorization, notification, or pre-treatment was absent. The payer required prior approval for the service and had none on file when it processed the claim.

Can I bill the patient for a CO-197 denial?

Generally no. CO-197 usually carries the Contractual Obligation group code, making the amount a provider write-off, because obtaining authorization is the provider's responsibility. Verify the group code and your contract before considering any patient billing.

Can I still get authorization after a CO-197?

Sometimes. Many payers allow a retroactive authorization within a limited window after the service, so act quickly. If the service truly required authorization and none can be obtained, the appeal rests on proving it was not required or on documented extenuating circumstances.

How do I prevent CO-197 denials?

Maintain an authorization tracker for the services your payers gate — testing, higher levels of care, and extended sessions — and verify approval before the patient is seen. Watching unit counts and expiration dates prevents most authorization-absent denials.

Informational only — not legal, medical, or billing advice. Always verify against your current payer contract and policy.

Fix CO-197 denials automatically

Undeny drafts a retro-authorization request or medical-necessity appeal in seconds. Generate an appeal · Browse denial codes