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 |
|---|---|---|
| N770 | The adjustment request received from the provider has been processed. Your original c… | Details → |
| N771 | Alert: Under Federal law you cannot charge more than the limiting charge amount. | Details → |
| N771 | Alert: Under Federal law you cannot charge more than the limiting charge amount. | Details → |
| N772 | Alert: Rebill urgent/emergent and ancillary services separately. | Details → |
| N772 | Alert: Rebill urgent/emergent and ancillary services separately. | Details → |
| N773 | Drug supplied not obtained from specialty vendor. | Details → |
| N773 | Drug supplied not obtained from specialty vendor. | Details → |
| N774 | Alert: Refer to your Third Party Processor Agreement for specific information on fees… | Details → |
| N774 | Alert: Refer to your Third Party Processor Agreement for specific information on fees… | Details → |
| N775 | Payment adjusted based on x-ray radiograph on film. | Details → |
| N775 | Payment adjusted based on x-ray radiograph on film. | Details → |
| N776 | This service is not a covered Telehealth service. | Details → |
| N776 | This service is not a covered Telehealth service. | Details → |
| N777 | Missing Assignment of Benefits Indicator. | Details → |
| N777 | Missing Assignment of Benefits Indicator. | Details → |
| N778 | Missing Primary Care Physician Information. | Details → |
| N778 | Missing Primary Care Physician Information. | Details → |
| N779 | Replacement/Void claims cannot be submitted until the original claim has finalized. P… | Details → |
| N779 | Replacement/Void claims cannot be submitted until the original claim has finalized. P… | Details → |
| N78 | The necessary components of the child and teen checkup (EPSDT) were not completed. | Details → |
| N78 | The necessary components of the child and teen checkup (EPSDT) were not completed. | Details → |
| N780 | Missing/incomplete/invalid end therapy date. | Details → |
| N780 | Missing/incomplete/invalid end therapy date. | Details → |
| N781 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N781 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N782 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N782 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N783 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N783 | Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary. Review your records for… | Details → |
| N784 | Missing comprehensive procedure code. | Details → |
| N784 | Missing comprehensive procedure code. | Details → |
| N785 | Missing current radiology film/images. | Details → |
| N785 | Missing current radiology film/images. | Details → |
| N786 | Benefit limitation for the orthodontic active and/or retention phase of treatment. | Details → |
| N786 | Benefit limitation for the orthodontic active and/or retention phase of treatment. | Details → |
| N787 | Alert: Under 42 CFR 410.43, an eligible Partial Hospitalization Program (PHP) patient… | Details → |
| N787 | Alert: Under 42 CFR 410.43, an eligible Partial Hospitalization Program (PHP) patient… | Details → |
| N788 | Alert: The third-party administrator/review organization did not receive the required… | Details → |
| N788 | Alert: The third-party administrator/review organization did not receive the required… | Details → |
| N789 | Clinical Trial is not a covered benefit. | Details → |
| N789 | Clinical Trial is not a covered benefit. | Details → |
| N79 | Service billed is not compatible with patient location information. | Details → |
| N79 | Service billed is not compatible with patient location information. | Details → |
| N790 | Provider/supplier not accredited for product/service. | Details → |
| N790 | Provider/supplier not accredited for product/service. | Details → |
| N791 | Missing history & physical report. | Details → |
| N791 | Missing history & physical report. | Details → |
| N792 | Incomplete/invalid history & physical report. | Details → |
| N792 | Incomplete/invalid history & physical report. | Details → |
| N793 | Alert: Starting January 1, 2020, Medicare will ONLY accept claims submitted with the … | Details → |
| N793 | Alert: Starting January 1, 2020, Medicare will ONLY accept claims submitted with the … | Details → |
| N794 | Payment adjusted based on type of technology used. | Details → |
| N794 | Payment adjusted based on type of technology used. | Details → |
| N795 | Item must be resubmitted as a purchase. | Details → |
| N795 | Item must be resubmitted as a purchase. | Details → |
| N796 | Missing/incomplete/invalid Hemoglobin (Hb or Hgb) value. | Details → |
| N796 | Missing/incomplete/invalid Hemoglobin (Hb or Hgb) value. | Details → |
| N797 | Missing/incomplete/invalid date qualifier. | Details → |
| N797 | Missing/incomplete/invalid date qualifier. | Details → |
| N798 | Submit a void request for the original claim and resubmit a new claim. | 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.