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 |
|---|---|---|
| N798 | Submit a void request for the original claim and resubmit a new claim. | Details → |
| N799 | Submitted identifier must be an individual identifier, not group identifier. | Details → |
| N799 | Submitted identifier must be an individual identifier, not group identifier. | Details → |
| N8 | Crossover claim denied by previous payer and complete claim data not forwarded. Resub… | Details → |
| N8 | Crossover claim denied by previous payer and complete claim data not forwarded. Resub… | Details → |
| N80 | Missing/incomplete/invalid prenatal screening information. | Details → |
| N80 | Missing/incomplete/invalid prenatal screening information. | Details → |
| N800 | Only one service date is allowed per claim. | Details → |
| N800 | Only one service date is allowed per claim. | Details → |
| N801 | Services performed in a Medicare participating or CAH facility under a self-insured t… | Details → |
| N801 | Services performed in a Medicare participating or CAH facility under a self-insured t… | Details → |
| N802 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N802 | This claim/service is not payable under our service area. The claim must be filed to … | Details → |
| N803 | Submission of the claim for the service rendered is the responsibility of the Contrac… | Details → |
| N803 | Submission of the claim for the service rendered is the responsibility of the Contrac… | Details → |
| N804 | Alert: The claim/service was processed through the Outpatient Code Editor (OCE). | Details → |
| N804 | Alert: The claim/service was processed through the Outpatient Code Editor (OCE). | Details → |
| N805 | Alert: The claim/service was processed through the Correct Code Editor (CCE). | Details → |
| N805 | Alert: The claim/service was processed through the Correct Code Editor (CCE). | Details → |
| N806 | Payment is included in the Global transplant allowance. | Details → |
| N806 | Payment is included in the Global transplant allowance. | Details → |
| N807 | Payment adjustment based on the Merit-based Incentive Payment System (MIPS). | Details → |
| N807 | Payment adjustment based on the Merit-based Incentive Payment System (MIPS). | Details → |
| N808 | Not covered for this provider type / provider specialty. | Details → |
| N808 | Not covered for this provider type / provider specialty. | Details → |
| N809 | Alert: The fee schedule amount for this service was adjusted based on prior competiti… | Details → |
| N809 | Alert: The fee schedule amount for this service was adjusted based on prior competiti… | Details → |
| N81 | Procedure billed is not compatible with tooth surface code. | Details → |
| N81 | Procedure billed is not compatible with tooth surface code. | Details → |
| N810 | Alert: Due to federal, state or local disaster declaration, this claim has been proce… | Details → |
| N810 | Alert: Due to federal, state or local disaster declaration, this claim has been proce… | Details → |
| N811 | Missing Federal Sequestration Reduction from Prior Payer. | Details → |
| N811 | Missing Federal Sequestration Reduction from Prior Payer. | Details → |
| N812 | The start service date through end service date cannot span greater than 18 months. | Details → |
| N812 | The start service date through end service date cannot span greater than 18 months. | Details → |
| N815 | Missing/Incomplete/Invalid NDC Unit Count | Details → |
| N815 | Missing/Incomplete/Invalid NDC Unit Count | Details → |
| N816 | Missing/Incomplete/Invalid NDC Unit of Measure | Details → |
| N816 | Missing/Incomplete/Invalid NDC Unit of Measure | Details → |
| N817 | Alert: Applicable laboratories are required to collect and report private payor data … | Details → |
| N817 | Alert: Applicable laboratories are required to collect and report private payor data … | Details → |
| N818 | Claims Dates of Service do not match Electronic Visit Verification System. | Details → |
| N818 | Claims Dates of Service do not match Electronic Visit Verification System. | Details → |
| N819 | Patient not enrolled in Electronic Visit Verification System. | Details → |
| N819 | Patient not enrolled in Electronic Visit Verification System. | Details → |
| N82 | Provider must accept insurance payment as payment in full when a third party payer co… | Details → |
| N82 | Provider must accept insurance payment as payment in full when a third party payer co… | Details → |
| N820 | Electronic Visit Verification System units do not meet requirements of visit. | Details → |
| N820 | Electronic Visit Verification System units do not meet requirements of visit. | Details → |
| N821 | Electronic Visit Verification System visit not found. | Details → |
| N821 | Electronic Visit Verification System visit not found. | Details → |
| N822 | Missing procedure modifier(s). | Details → |
| N822 | Missing procedure modifier(s). | Details → |
| N823 | Incomplete/Invalid procedure modifier(s). | Details → |
| N823 | Incomplete/Invalid procedure modifier(s). | Details → |
| N824 | Electronic Visit Verification (EVV) data must be submitted through EVV Vendor. | Details → |
| N824 | Electronic Visit Verification (EVV) data must be submitted through EVV Vendor. | Details → |
| N825 | Early intervention guidelines were not met. | Details → |
| N825 | Early intervention guidelines were not met. | Details → |
| N826 | Patient did not meet the inclusion criteria for the Medicare Shared Savings Program. | 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.