Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)
Group code
OA (CO for state WC)
Category
Duplicate
Risk level
Medium
Appealable
Review Required
Common RARC pairings
RARCs (Remittance Advice Remark Codes) provide the specific reason detail alongside CARC 18 on the 835 electronic remittance. These are the RARCs seen most often with this CARC.
| RARC | Meaning |
|---|---|
| N111 | No appeal right except duplicate claim/service issue. This service was included in a claim that has been previously billed and adjudicated. |
| N347 | Your claim for a referred or purchased service cannot be paid because payment has already been made for this same service to another provider by a payment contractor representing the payer. |
| N389 | Duplicate prescription number submitted. |
| N522 | Duplicate of a claim processed, or to be processed, as a crossover claim. |
| N702 | Decision based on review of previously adjudicated claims or for claims in process for the same/similar type of services. |
See the full resolution workflow for CARC 18
Members of the EDI-Code Intelligence Lab get the step-by-step rework path, appeal language, root-cause drivers, and prevention checklist for every CARC and RARC pairing, plus payer-specific quirks.
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