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 |
|---|---|---|
| N853 | The number of modalities performed per session exceeds our acceptable maximum. | Details → |
| N854 | Alert: If you have primary other health insurance (OHI) coverage that has denied serv… | Details → |
| N854 | Alert: If you have primary other health insurance (OHI) coverage that has denied serv… | Details → |
| N855 | This coverage is subject to the exclusive jurisdiction of ERISA (1974), U.S.C. SEC 10… | Details → |
| N855 | This coverage is subject to the exclusive jurisdiction of ERISA (1974), U.S.C. SEC 10… | Details → |
| N856 | This coverage is not subject to the exclusive jurisdiction of ERISA (1974), U.S.C. SE… | Details → |
| N856 | This coverage is not subject to the exclusive jurisdiction of ERISA (1974), U.S.C. SE… | Details → |
| N857 | This claim has been adjusted/reversed. Refund any collected copayment to the member. | Details → |
| N857 | This claim has been adjusted/reversed. Refund any collected copayment to the member. | Details → |
| N858 | Alert: State regulations relating to an Out of Network Medical Emergency Care Act wer… | Details → |
| N858 | Alert: State regulations relating to an Out of Network Medical Emergency Care Act wer… | Details → |
| N859 | Alert: The Federal No Surprise Billing Act was applied to the processing of this clai… | Details → |
| N859 | Alert: The Federal No Surprise Billing Act was applied to the processing of this clai… | Details → |
| N86 | A failed trial of pelvic muscle exercise training is required in order for biofeedbac… | Details → |
| N86 | A failed trial of pelvic muscle exercise training is required in order for biofeedbac… | Details → |
| N860 | Alert: The Federal No Surprise Billing Act Qualified Payment Amount (QPA) was used to… | Details → |
| N860 | Alert: The Federal No Surprise Billing Act Qualified Payment Amount (QPA) was used to… | Details → |
| N861 | Alert: Mismatch between the submitted Patient Liability/Share of Cost and the amount … | Details → |
| N861 | Alert: Mismatch between the submitted Patient Liability/Share of Cost and the amount … | Details → |
| N862 | Alert: Member cost share is in compliance with the No Surprises Act, and is calculate… | Details → |
| N862 | Alert: Member cost share is in compliance with the No Surprises Act, and is calculate… | Details → |
| N863 | Alert: This claim is subject to the No Surprises Act (NSA). The amount paid is the fi… | Details → |
| N863 | Alert: This claim is subject to the No Surprises Act (NSA). The amount paid is the fi… | Details → |
| N864 | Alert: This claim is subject to the No Surprises Act provisions that apply to emergen… | Details → |
| N864 | Alert: This claim is subject to the No Surprises Act provisions that apply to emergen… | Details → |
| N865 | Alert: This claim is subject to the No Surprises Act provisions that apply to nonemer… | Details → |
| N865 | Alert: This claim is subject to the No Surprises Act provisions that apply to nonemer… | Details → |
| N866 | Alert: This claim is subject to the No Surprises Act provisions that apply to service… | Details → |
| N866 | Alert: This claim is subject to the No Surprises Act provisions that apply to service… | Details → |
| N867 | Alert: Cost sharing was calculated based on a specified state law, in accordance with… | Details → |
| N867 | Alert: Cost sharing was calculated based on a specified state law, in accordance with… | Details → |
| N868 | Alert: Cost sharing was calculated based on an All-Payer Model Agreement, in accordan… | Details → |
| N868 | Alert: Cost sharing was calculated based on an All-Payer Model Agreement, in accordan… | Details → |
| N869 | Alert: Cost sharing was calculated based on the qualifying payment amount, in accorda… | Details → |
| N869 | Alert: Cost sharing was calculated based on the qualifying payment amount, in accorda… | Details → |
| N87 | Home use of biofeedback therapy is not covered. | Details → |
| N87 | Home use of biofeedback therapy is not covered. | Details → |
| N870 | Alert: In accordance with the No Surprises Act, cost sharing was based on the billed … | Details → |
| N870 | Alert: In accordance with the No Surprises Act, cost sharing was based on the billed … | Details → |
| N871 | Alert: This initial payment was calculated based on a specified state law, in accorda… | Details → |
| N871 | Alert: This initial payment was calculated based on a specified state law, in accorda… | Details → |
| N872 | Alert: This final payment was calculated based on a specified state law, in accordanc… | Details → |
| N872 | Alert: This final payment was calculated based on a specified state law, in accordanc… | Details → |
| N873 | Alert: This final payment was calculated based on an All-Payer Model Agreement, in ac… | Details → |
| N873 | Alert: This final payment was calculated based on an All-Payer Model Agreement, in ac… | Details → |
| N874 | Alert: This final payment was determined through open negotiation, in accordance with… | Details → |
| N874 | Alert: This final payment was determined through open negotiation, in accordance with… | Details → |
| N875 | Alert: This final payment equals the amount selected as the out-of-network rate by a … | Details → |
| N875 | Alert: This final payment equals the amount selected as the out-of-network rate by a … | Details → |
| N876 | Alert: This item or service is covered under the plan. This is a notice of denial of … | Details → |
| N876 | Alert: This item or service is covered under the plan. This is a notice of denial of … | Details → |
| N877 | Alert: This initial payment is provided in accordance with the No Surprises Act. The … | Details → |
| N877 | Alert: This initial payment is provided in accordance with the No Surprises Act. The … | Details → |
| N878 | Alert: The provider or facility specified that notice was provided and consent to bal… | Details → |
| N878 | Alert: The provider or facility specified that notice was provided and consent to bal… | Details → |
| N879 | Alert: The notice and consent to balance bill, and to be charged out-of-network cost … | Details → |
| N879 | Alert: The notice and consent to balance bill, and to be charged out-of-network cost … | Details → |
| N88 | Alert: This payment is being made conditionally. An HHA episode of care notice has be… | Details → |
| N88 | Alert: This payment is being made conditionally. An HHA episode of care notice has be… | Details → |
| N88 | Payment was made for this claim conditionally because an HHA episode of care has been… | 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.