Medical billing denial codes are standardized codes used by payers (insurance companies) to explain why a claim was denied, rejected, or adjusted. Understanding denial codes is essential for medical billers, coders, and revenue cycle management (RCM) professionals to recover lost revenue and prevent future denials.
This hub page provides comprehensive resources on the most common denial codes in medical billing, including CO (Contractual Obligation), PR (Patient Responsibility), OA (Other Adjustment), PI (Payer Initiated), and CR (Correction and Reversal) categories.
Denial Code Guides:
- CO-97: Procedure or service is not paid for separately (bundling denial)
- CO-96: Non-covered charge — the payer has determined the service isn’t eligible for reimbursement under the patient’s plan
- CO-197: Precertification/authorization/notification absent
Related resource: Guide to building a CO-97 denial tracking dashboard in your PM system.
Use our guides to understand each denial code, find the root cause, and implement the correct appeals and prevention strategies. We’re actively expanding this library with new denial code guides — check back soon.