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 |
|---|---|---|
| MA85 | Our records indicate that a primary payer exists (other than ourselves); however, you… | Details → |
| MA86 | Missing/incomplete/invalid group or policy number of the insured for the primary cove… | Details → |
| MA86 | Missing/incomplete/invalid group or policy number of the insured for the primary cove… | Details → |
| MA87 | Missing/incomplete/invalid insured's name for the primary payer. | Details → |
| MA87 | Missing/incomplete/invalid insured's name for the primary payer. | Details → |
| MA88 | Missing/incomplete/invalid insured's address and/or telephone number for the primary … | Details → |
| MA88 | Missing/incomplete/invalid insured's address and/or telephone number for the primary … | Details → |
| MA89 | Missing/incomplete/invalid patient's relationship to the insured for the primary paye… | Details → |
| MA89 | Missing/incomplete/invalid patient's relationship to the insured for the primary paye… | Details → |
| MA90 | Missing/incomplete/invalid employment status code for the primary insured. | Details → |
| MA90 | Missing/incomplete/invalid employment status code for the primary insured. | Details → |
| MA91 | Alert: This determination is the result of the appeal you filed. | Details → |
| MA91 | Alert: This determination is the result of the appeal you filed. | Details → |
| MA92 | Missing plan information for other insurance. | Details → |
| MA92 | Missing plan information for other insurance. | Details → |
| MA93 | Non-PIP (Periodic Interim Payment) claim. | Details → |
| MA93 | Non-PIP (Periodic Interim Payment) claim. | Details → |
| MA94 | Did not enter the statement 'Attending physician not hospice employee' on the claim f… | Details → |
| MA94 | Did not enter the statement 'Attending physician not hospice employee' on the claim f… | Details → |
| MA95 | A not otherwise classified or unlisted procedure code(s) was billed but a narrative d… | Details → |
| MA95 | A not otherwise classified or unlisted procedure code(s) was billed but a narrative d… | Details → |
| MA96 | Claim rejected. Coded as a Medicare Managed Care Demonstration but patient is not enr… | Details → |
| MA96 | Claim rejected. Coded as a Medicare Managed Care Demonstration but patient is not enr… | Details → |
| MA97 | Missing/incomplete/invalid Medicare Managed Care Demonstration contract number or cli… | Details → |
| MA97 | Missing/incomplete/invalid Medicare Managed Care Demonstration contract number or cli… | Details → |
| MA98 | Claim Rejected. Does not contain the correct Medicare Managed Care Demonstration cont… | Details → |
| MA98 | Claim Rejected. Does not contain the correct Medicare Managed Care Demonstration cont… | Details → |
| MA99 | Missing/incomplete/invalid Medigap information. | Details → |
| MA99 | Missing/incomplete/invalid Medigap information. | Details → |
| N1 | Alert: You may appeal this decision in writing within the required time limits follow… | Details → |
| N1 | Alert: You may appeal this decision in writing within the required time limits follow… | Details → |
| N10 | Adjustment based on the findings of a review organization/professional consult/manual… | Details → |
| N10 | Adjustment based on the findings of a review organization/professional consult/manual… | Details → |
| N100 | PPS (Prospect Payment System) code corrected during adjudication. | Details → |
| N100 | PPS (Prospect Payment System) code corrected during adjudication. | Details → |
| N101 | Additional information is needed in order to process this claim. Please resubmit the … | Details → |
| N101 | Additional information is needed in order to process this claim. Please resubmit the … | Details → |
| N102 | This claim has been denied without reviewing the medical/dental record because the re… | Details → |
| N102 | This claim has been denied without reviewing the medical/dental record because the re… | Details → |
| N103 | Records indicate this patient was a prisoner or in custody of a Federal, State, or lo… | Details → |
| N103 | Records indicate this patient was a prisoner or in custody of a Federal, State, or lo… | Details → |
| N104 | This claim/service is not payable under our claims jurisdiction area. You can identif… | Details → |
| N104 | This claim/service is not payable under our claims jurisdiction area. You can identif… | Details → |
| N104 | Claim was submitted to incorrect Jurisdiction Claim must be submitted to the Jurisdi… | Details → |
| N105 | This is a misdirected claim/service for an RRB beneficiary. Submit paper claims to th… | Details → |
| N105 | This is a misdirected claim/service for an RRB beneficiary. Submit paper claims to th… | Details → |
| N106 | Payment for services furnished to Skilled Nursing Facility (SNF) inpatients (except f… | Details → |
| N106 | Payment for services furnished to Skilled Nursing Facility (SNF) inpatients (except f… | Details → |
| N107 | Services furnished to Skilled Nursing Facility (SNF) inpatients must be billed on the… | Details → |
| N107 | Services furnished to Skilled Nursing Facility (SNF) inpatients must be billed on the… | Details → |
| N108 | Missing/incomplete/invalid upgrade information. | Details → |
| N108 | Missing/incomplete/invalid upgrade information. | Details → |
| N109 | Alert: This claim/service was chosen for complex review. | Details → |
| N109 | Alert: This claim/service was chosen for complex review. | Details → |
| N11 | Denial reversed because of medical review. | Details → |
| N11 | Denial reversed because of medical review. | Details → |
| N110 | This facility is not certified for film mammography. | Details → |
| N110 | This facility is not certified for film mammography. | Details → |
| N111 | No appeal right except duplicate claim/service issue. This service was included in a … | Details → |
| N111 | No appeal right except duplicate claim/service issue. This service was included in a … | 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.