MBI Claim Denials CO16 and N382 Due to Outdated MBI Numbers

To protect patient's private information, Medicare beneficiaries will receive a new Medicare Beneficiary Identifier (MBI) number if they report their Medicare card lost or stolen. When a patient receives a new MBI number, providers must immediately switch to billing with the new MBI. Billing with the old MBI may result in receiving the below CARC and RARC rejection codes:

  • CO16: Claim/Service lack information or has submission/billing error(s).
  • N382: Missing/Incomplete/Invalid patient identifier

If you receive a denial with the above remark codes, please verify the patient's MBI using the NMP MBI Lookup Tool.


Last Updated Feb 13 , 2023