CO-197 Denial Code: Prior Authorization Absent (Meaning and Fix)

CO-197 means the payer has no record of a required precertification, authorization or notification for the service. The provider is responsible for the amount. Before appealing, check whether an authorization actually existed: many CO-197 denials come from an authorization that did not match the claim, not from one that was never requested.

What does CO-197 mean?

CARC 197 is officially described as “Precertification/authorization/notification/pre-treatment absent.” The wording is published in the X12 Claim Adjustment Reason Code list (opens in a new tab).

The payer is saying it could not tie the claim to an approval. That can mean no request was made, the request was made but not approved, or the approval exists but covers a different service, date range, provider or location than the one billed.

Common causes of CO-197

Cause	Where to look
No authorization was requested	Scheduling and referral workflow
Authorization number missing or wrong on the claim	Claim form and charge entry
Approved CPT code differs from the code billed	Authorization letter and the procedure note
Service fell outside the approved dates or visit count	Authorization letter and the date of service
Approval issued to a different provider or facility	Authorization letter and the rendering provider

How to fix a CO-197 denial

1. Search the payer portal and your records for any authorization covering the patient, service and date.
2. If one exists, correct the claim so the authorization number, code, dates and provider match, and resubmit.
3. If the code changed during the procedure, ask the payer whether it will update the authorization. Many allow this within a short window.
4. If no authorization exists, ask whether the payer accepts retro-authorization for urgent or emergency situations.
5. If neither works and the service was medically necessary, file an appeal with the clinical records and any proof of attempts to obtain approval.

Correct or appeal a CO-197 denial?

Correct when the authorization existed and the claim did not match it. Appeal when the service was urgent, the payer’s requirement was unclear, or you have proof the request was submitted. If the authorization was simply never requested, appeals rarely succeed and the fix belongs in the front-end process.

How to prevent CO-197

• Check authorization requirements at scheduling, not at check-in.
• Record the authorization number, approved codes, dates and visit count in the practice management system.
• Recheck before the visit when the planned service changes.
• Track expiring authorizations for ongoing care such as therapy.
• See how our prior authorization service handles requests and tracking.

Frequently asked questions

Can I bill the patient for CO-197?

Not when the group code is CO. The provider is responsible for the missing authorization.

What is the difference between CO-197 and CO-15?

CARC 15 means the authorization number is missing, invalid, or does not apply to the billed services or provider, while 197 means the required authorization is absent altogether. Both are fixed by matching the claim to a valid approval.

Does an authorization guarantee payment?

No. An approval confirms the planned service meets the payer’s requirements, but the claim still has to meet eligibility, coding and benefit rules.

Related denial code guides

• How to read a claim denial: CARCs, RARCs and group codes
• CO-16 denial code
• CO-97 denial code
• CO-50 denial code
• CO-4 denial code
• PR-1 denial code

Code descriptions are quoted from X12 at the time of writing and are revised from time to time. Payer policies and your contracts decide what is billable and appealable.