Instantly find explanations, causes, and resolution steps for every Claim Adjustment Reason Code (CARC) and Remark Code.
Claim Adjustment Reason Codes (CARC) explain why a payment differs from what was billed. Every 835 ERA and EOB uses these standardized codes.
Search any code or keyword above. Each page includes the full description, common causes, resolution steps, and appeal guidance.
Each denial code page also links to a dedicated Remark Code page — optimized for providers searching for ERA remark code context.
Most denials are reversible. Our guides walk you through the correct steps to correct, resubmit, or formally appeal each denial type.
| Code | Description | View |
|---|---|---|
| N347 | Your claim for a referred or purchased service cannot be paid because payment has alr… | Details → |
| N347 | Your claim for a referred or purchased service cannot be paid because payment has alr… | Details → |
| N348 | You chose that this service/supply/drug would be rendered/supplied and billed by a di… | Details → |
| N348 | You chose that this service/supply/drug would be rendered/supplied and billed by a di… | Details → |
| N349 | The administration method and drug must be reported to adjudicate this service. | Details → |
| N349 | The administration method and drug must be reported to adjudicate this service. | Details → |
| N35 | Program integrity/utilization review decision. | Details → |
| N35 | Program integrity/utilization review decision. | Details → |
| N350 | Missing/incomplete/invalid description of service for a Not Otherwise Classified (NOC… | Details → |
| N350 | Missing/incomplete/invalid description of service for a Not Otherwise Classified (NOC… | Details → |
| N350 | Claim/service lacks information or has submission/billing error(s) Missing/incomplet… | Details → |
| N351 | Service date outside of the approved treatment plan service dates. | Details → |
| N351 | Service date outside of the approved treatment plan service dates. | Details → |
| N352 | Alert: There are no scheduled payments for this service. Submit a claim for each pati… | Details → |
| N352 | Alert: There are no scheduled payments for this service. Submit a claim for each pati… | Details → |
| N353 | Alert: Benefits have been estimated, when the actual services have been rendered, add… | Details → |
| N353 | Alert: Benefits have been estimated, when the actual services have been rendered, add… | Details → |
| N354 | Incomplete/invalid invoice. | Details → |
| N354 | Incomplete/invalid invoice. | Details → |
| N355 | Alert: The law permits exceptions to the refund requirement in two cases: - If you di… | Details → |
| N355 | Alert: The law permits exceptions to the refund requirement in two cases: - If you di… | Details → |
| N356 | Not covered when performed with, or subsequent to, a non-covered service. | Details → |
| N356 | Not covered when performed with, or subsequent to, a non-covered service. | Details → |
| N357 | Time frame requirements between this service/procedure/supply and a related service/p… | Details → |
| N357 | Time frame requirements between this service/procedure/supply and a related service/p… | Details → |
| N358 | Alert: This decision may be reviewed if additional documentation as described in the … | Details → |
| N358 | Alert: This decision may be reviewed if additional documentation as described in the … | Details → |
| N359 | Missing/incomplete/invalid height. | Details → |
| N359 | Missing/incomplete/invalid height. | Details → |
| N36 | Claim must meet primary payer's processing requirements before we can consider paymen… | Details → |
| N36 | Claim must meet primary payer's processing requirements before we can consider paymen… | Details → |
| N360 | Alert: Coordination of benefits has not been calculated when estimating benefits for … | Details → |
| N360 | Alert: Coordination of benefits has not been calculated when estimating benefits for … | Details → |
| N361 | Payment adjusted based on multiple diagnostic imaging procedure rules | Details → |
| N361 | Payment adjusted based on multiple diagnostic imaging procedure rules | Details → |
| N362 | The number of Days or Units of Service exceeds our acceptable maximum. | Details → |
| N362 | The number of Days or Units of Service exceeds our acceptable maximum. | Details → |
| N363 | Alert: in the near future we are implementing new policies/procedures that would affe… | Details → |
| N363 | Alert: in the near future we are implementing new policies/procedures that would affe… | Details → |
| N364 | Alert: According to our agreement, you must waive the deductible and/or coinsurance a… | Details → |
| N364 | Alert: According to our agreement, you must waive the deductible and/or coinsurance a… | Details → |
| N365 | This procedure code is not payable. It is for reporting/information purposes only. | Details → |
| N365 | This procedure code is not payable. It is for reporting/information purposes only. | Details → |
| N366 | Requested information not provided. The claim will be reopened if the information pre… | Details → |
| N366 | Requested information not provided. The claim will be reopened if the information pre… | Details → |
| N367 | Alert: The claim information has been forwarded to a Consumer Spending Account proces… | Details → |
| N367 | Alert: The claim information has been forwarded to a Consumer Spending Account proces… | Details → |
| N368 | You must appeal the determination of the previously adjudicated claim. | Details → |
| N368 | You must appeal the determination of the previously adjudicated claim. | Details → |
| N369 | Alert: Although this claim has been processed, it is deficient according to state leg… | Details → |
| N369 | Alert: Although this claim has been processed, it is deficient according to state leg… | Details → |
| N37 | Missing/incomplete/invalid tooth number/letter. | Details → |
| N37 | Missing/incomplete/invalid tooth number/letter. | Details → |
| N370 | Billing exceeds the rental months covered/approved by the payer. | Details → |
| N370 | Billing exceeds the rental months covered/approved by the payer. | Details → |
| N370 | Maximum rental months have been paid for item | Details → |
| N370 | Oxygen equipment has exceeded number of approved paid rentals | Details → |
| N371 | Alert: title of this equipment must be transferred to the patient. | Details → |
| N371 | Alert: title of this equipment must be transferred to the patient. | Details → |
| N372 | Only reasonable and necessary maintenance/service charges are covered. | Details → |
Medical claim denial codes — formally known as Claim Adjustment Reason Codes (CARC) — are standardized identifiers maintained by the X12 standards body and used across all Medicare, Medicaid, and commercial payer 835 electronic remittance transactions. When a claim is paid at a different amount than billed, at least one CARC code must accompany the remittance advice to indicate the specific reason for the adjustment.
The most frequently encountered codes include CO-16 (missing or invalid claim information), CO-45 (charges exceeding fee schedule), PR-1 (patient deductible), CO-29 (timely filing deadline exceeded), and CO-4 (procedure code inconsistent with modifier). Each represents a distinct, actionable reason that has a defined resolution pathway.