CARC 197 / CO-197: Prior Authorization Denials in Medical Billing
October 29, 2026Learn what CARC 197 and CO-197 mean, how prior authorization denials appear in an X12 835 ERA, and how to investigate authorization-related claim adjustments.
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.