Some of the most common Medicare denial codes are CO-97, CO-50, PR-B9, CO-96 and CO-31. Other denial codes indicate missing or incorrect information, notes Noridian Healthcare Solutions. Medicare denial codes, which indicate why a claim was not paid or paid differently than was submitted by the health care provider, appear in the form of Claim Adjustment Reason Codes or Remittance Advice Remark Codes.
Denial code CO-97 indicates that the claim is a duplicate of one already submitted, explains Noridian Healthcare Solutions. Code CO-50 indicates that the billed service is denied on the basis of being a noncovered service because it is not deemed a medical necessity. Code PR-B9 denies payment of the claim because the patient is enrolled in a hospice. Code CO-96 indicates that the submitted claim is a noncovered service. Code CO-31 denies the claim because the patient cannot be identified as a Medicare-insured individual.
Another common denial reason is missing or incorrect information that is required on the claim, according to Noridian Healthcare Solutions. This denial can appear with the code CO-16, which indicates that either the claim or the service item lacks information or has incorrect billing errors required for adjudication, code M51, which indicates that procedure codes are missing, incomplete or invalid, or code N56, indicating that the billed procedure code was not correct or valid for either the services or date of service billed.