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 |
|---|---|---|
| N558 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N558 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N559 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N559 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N56 | Procedure code billed is not correct/valid for the services billed or the date of ser… | Details → |
| N56 | Non-covered charge(s) Procedure code billed is not correct/valid for the services bi… | Details → |
| N56 | Procedure code billed is not correct/valid for the services billed or the date of ser… | Details → |
| N560 | The pilot program requires an interim or final claim within 60 days of the Notice of … | Details → |
| N560 | The pilot program requires an interim or final claim within 60 days of the Notice of … | Details → |
| N561 | The bundled claim originally submitted for this episode of care includes related read… | Details → |
| N561 | The bundled claim originally submitted for this episode of care includes related read… | Details → |
| N562 | The provider number of your incoming claim does not match the provider number on the … | Details → |
| N562 | The provider number of your incoming claim does not match the provider number on the … | Details → |
| N563 | Alert: Missing required provider/supplier issuance of advance patient notice of non-c… | Details → |
| N563 | Alert: Missing required provider/supplier issuance of advance patient notice of non-c… | Details → |
| N564 | Patient did not meet the inclusion criteria for the demonstration project or pilot pr… | Details → |
| N564 | Patient did not meet the inclusion criteria for the demonstration project or pilot pr… | Details → |
| N565 | Alert: This non-payable reporting code requires a modifier. Future claims containing … | Details → |
| N565 | HCPCS code is inconsistent with modifier used or a required modifier is missing Item… | Details → |
| N565 | Alert: This non-payable reporting code requires a modifier. Future claims containing … | Details → |
| N566 | Alert: This procedure code requires functional reporting. Future claims containing th… | Details → |
| N566 | Alert: This procedure code requires functional reporting. Future claims containing th… | Details → |
| N567 | Not covered when considered preventative. | Details → |
| N567 | Not covered when considered preventative. | Details → |
| N568 | Alert: Initial payment based on the Notice of Admission (NOA) under the Bundled Payme… | Details → |
| N568 | Alert: Initial payment based on the Notice of Admission (NOA) under the Bundled Payme… | Details → |
| N569 | Not covered when performed for the reported diagnosis. | Details → |
| N569 | Not covered when performed for the reported diagnosis. | Details → |
| N57 | Missing/incomplete/invalid prescribing date. | Details → |
| N57 | Missing/incomplete/invalid prescribing date. | Details → |
| N570 | Missing/incomplete/invalid credentialing data. | Details → |
| N570 | Missing/incomplete/invalid credentialing data. | Details → |
| N570 | This provider was not certified/eligible to be paid for this procedure/service on thi… | Details → |
| N571 | Alert: Payment will be issued quarterly by another payer/contractor. | Details → |
| N571 | Alert: Payment will be issued quarterly by another payer/contractor. | Details → |
| N572 | This procedure is not payable unless appropriate non-payable reporting codes and asso… | Details → |
| N572 | This procedure is not payable unless appropriate non-payable reporting codes and asso… | Details → |
| N573 | Alert: You have been overpaid and must refund the overpayment. The refund will be req… | Details → |
| N573 | Alert: You have been overpaid and must refund the overpayment. The refund will be req… | Details → |
| N574 | Our records indicate the ordering/referring provider is of a type/specialty that cann… | Details → |
| N574 | Our records indicate the ordering/referring provider is of a type/specialty that cann… | Details → |
| N575 | Mismatch between the submitted ordering/referring provider name and the ordering/refe… | Details → |
| N575 | Item(s) billed did not have a valid ordering physician name | Details → |
| N575 | Mismatch between the submitted ordering/referring provider name and the ordering/refe… | Details → |
| N576 | Services not related to the specific incident/claim/accident/loss being reported. | Details → |
| N576 | Services not related to the specific incident/claim/accident/loss being reported. | Details → |
| N577 | Personal Injury Protection (PIP) Coverage. | Details → |
| N577 | Personal Injury Protection (PIP) Coverage. | Details → |
| N578 | Coverages do not apply to this loss. | Details → |
| N578 | Coverages do not apply to this loss. | Details → |
| N579 | Medical Payments Coverage (MPC). | Details → |
| N579 | Medical Payments Coverage (MPC). | Details → |
| N58 | Missing/incomplete/invalid patient liability amount. | Details → |
| N58 | Missing/incomplete/invalid patient liability amount. | Details → |
| N580 | Determination based on the provisions of the insurance policy. | Details → |
| N580 | Determination based on the provisions of the insurance policy. | Details → |
| N581 | Investigation of coverage eligibility is pending. | Details → |
| N581 | Investigation of coverage eligibility is pending. | Details → |
| N582 | Benefits suspended pending the patient's cooperation. | Details → |
| N582 | Benefits suspended pending the patient's cooperation. | 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.