CARC 50 / CO-50: Medical Necessity Denials in Medical Billing
October 29, 2026Learn what CARC 50 and CO-50 mean, how medical necessity denials appear in an X12 835 ERA, and how to investigate documentation, coverage and appeals.
CARC 22 / CO-22: Coordination of Benefits Denials in Medical Billing
October 27, 2026Learn what CARC 22 and CO-22 mean, how coordination of benefits affects medical claims, how CARC 23 and OA-23 differ, and how to investigate COB denials.
CARC 29 / CO-29: Timely Filing Denials in Medical Billing
October 22, 2026Learn what CARC 29 and CO-29 mean, how timely filing denials appear in an X12 835 ERA, what counts as proof of timely filing, and how to investigate them.
CARC 16 / CO-16: Missing or Incorrect Claim Information
October 21, 2026Learn what CARC 16 and CO-16 mean in medical billing, how to read associated RARCs in an X12 835, and how to investigate missing or incorrect claim information.
What Are Claim Adjustment Group Codes (CO, PR, OA & PI)?
October 21, 2026Learn what CO, PR, OA and PI claim adjustment group codes mean, where they appear in the X12 835 CAS segment, and how they affect medical billing.