CO-197 Denial Code: Authorization or Precertification Absent
Many payers require approval before certain services, such as imaging, procedures, therapy beyond a visit threshold, and many behavioral health services. CARC 197 means the payer could not match an approved authorization to this claim line. That can mean no auth was requested, or an auth exists but does not match the claim.
The group code (CO, PR, OA, PI) tells you who is responsible. The CARC number tells you why.
CO-197 means the payer required prior authorization, precertification, or notification for this service and has none on file for this claim. First check whether an authorization actually exists and was just left off the claim or does not match it. If none was obtained, ask whether the payer allows a retroactive authorization.
Common causes of CO-197.
- Authorization never requested
- Authorization number missing from the claim
- Authorization expired or its approved units or visits were used up
- Auth issued for a different CPT code, provider, or location than billed
- Authorization requirement changed and the practice's list was not updated
How to work a CO-197 denial.
The order matters: confirm the facts before deciding between a corrected claim, a reconsideration, or an adjustment.
- 1Search the payer portal and your records for an authorization covering the date of service.
- 2If one exists, add the auth number to the claim and submit a corrected claim.
- 3If an auth exists but does not match the claim (code, units, provider), ask the payer to update it, then resubmit.
- 4If no auth exists, ask whether the payer accepts retroactive authorization requests and the time limit for them.
- 5If retro auth is not allowed, appeal with medical records for urgent situations. Otherwise, adjust per your contract. In-network claims usually cannot be billed to the patient.
How to keep CO-197 from coming back.
- Maintain an authorization requirements list by payer and code
- Track auth expiration dates and remaining units
- Check authorization status before every visit for services that require it
Fixing this at the source usually sits with prior authorization specialists →
Questions about CO-197.
Denials that often travel with this one.
CO-50: Not Deemed Medically Necessary
CO-50 means the payer decided the service was not medically necessary. How to review policy and documentation, build an appeal, and handle ABNs for Medicare.
Read about CO-50 →CO-151: Information Does Not Support Frequency or Units
CO-151 means the payer says the information submitted does not support this many services or units. How to check unit limits, documentation, and appeal.
Read about CO-151 →CO-252: Attachment or Documentation Required
CO-252 means the payer needs an attachment or other documentation to adjudicate the claim. How to send records correctly and avoid repeat requests.
Read about CO-252 →Add a Dedicated Denial Specialist
RCM Staff places trained denial management specialists inside your EHR and clearinghouse to work the queue, correct and appeal claims, and track root causes by payer.
Kevin Jamito has 18+ years of U.S. healthcare revenue cycle management experience across billing, coding, practice management, and offshore RCM operations. He founded RCM Staff to give U.S. healthcare teams dedicated Philippines-based specialists who work inside their existing systems.