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 |
|---|---|---|
| 105 | Tax withholding. Start: 01/01/1995 | Details → |
| 105 | Denied. Procedure code is incompatible with diagnosis code on the bill. | Details → |
| 106 | Incidental Incidental service(s) to primary procedure do not require separate reimbur… | Details → |
| 106 | Patient payment option/election not in effect. Start: 01/01/1995 | Details → |
| 106 | Denied. The therapeutic class and the diagnosis on the bill are incompatible. | Details → |
| 107 | Obsolete or invalid procedure code Obsolete or invalid procedure code | Details → |
| 107 | The related or qualifying claim/service was not identified on this claim. Usage: Refe… | Details → |
| 107 | Board charges are allowed for payment of food items only. Other items are not authori… | Details → |
| 107 | The related or qualifying claim/service was not identified on this claim. | Details → |
| 108 | Multiple unit or multiple modifier denial. Multiple unit or multiple modifier denial. | Details → |
| 108 | Rent/purchase guidelines were not met. Usage: Refer to the 835 Healthcare Policy Iden… | Details → |
| 108 | Payment of this service has been authorized as a retraining expense. | Details → |
| 108 | The equipment is billed as a purchased item when only covered if rented. | Details → |
| 109 | Unilateral/Bilateral procedure code Unilateral/Bilateral procedure code | Details → |
| 109 | Claim/service not covered by this payer/contractor. You must send the claim/service t… | Details → |
| 109 | Deduction taken to reimburse L&I for unauthorized or excess payment of this service. | Details → |
| 109 | Claim was submitted to incorrect Jurisdiction Claim must be submitted to the Jurisdi… | Details → |
| 110 | Mutually exclusive Two or more procedure codes are considered mutually exclusive. | Details → |
| 110 | Billing date predates service date. Start: 01/01/1995 | Details → |
| 110 | Paid technical component only. Professional component billed by and paid to another p… | Details → |
| 111 | Procedure does not require an Assistant Surgeon. Procedure does not require an Assist… | Details → |
| 111 | Not covered unless the provider accepts assignment. Start: 01/01/1995 | Details → |
| 111 | The procedure modifier(s) required for the surgery(s) on this bill is either invalid … | Details → |
| 112 | Age range discrepancy Provider assigned an age-specific procedure to a patient whose … | Details → |
| 112 | Service not furnished directly to the patient and/or not documented. Start: 01/01/19… | Details → |
| 112 | Units of service adjusted to comply with the maximum 40 hours payable for this servic… | Details → |
| 113 | Gender discrepancy Provider assigned a gender-specific procedure to a patient of the … | Details → |
| 113 | Payment denied because service/procedure was provided outside the United States or as… | Details → |
| 113 | When billing an unlisted procedure code a specific description of service must be on … | Details → |
| 114 | Invalid diagnosis code Invalid diagnosis code | Details → |
| 114 | Procedure/product not approved by the Food and Drug Administration. Start: 01/01/199… | Details → |
| 114 | Paid. Condition not accepted but retarding recovery from accepted condition. | Details → |
| 115 | Procedure postponed, canceled, or delayed. Start: 01/01/1995 | Last Modified: 09/30/… | Details → |
| 115 | Units of service for accommodations conflict with the covered dates listed on your bi… | Details → |
| 116 | OPPS The services reported on this claim are not separately reimbursable under OPPS. | Details → |
| 116 | The advance indemnification notice signed by the patient did not comply with requirem… | Details → |
| 116 | No payment made for this surgical service. It is included in flat fee for major surge… | Details → |
| 117 | Incorrect blood Line items billing for blood and products is incorrect. Please resubm… | Details → |
| 117 | Transportation is only covered to the closest facility that can provide the necessary… | Details → |
| 117 | The 1st procedure code modifier is either completely invalid or invalid for the servi… | Details → |
| 118 | Radiopharm Certain nuclear medicine procedures are performed with specific diagnostic… | Details → |
| 118 | ESRD network support adjustment. Start: 01/01/1995 | Last Modified: 09/30/2007 | Details → |
| 118 | This service has already been billed by and paid to another provider. | Details → |
| 119 | G0739 G0379 must be billed in conjunction with G0378. | Details → |
| 119 | Benefit maximum for this time period or occurrence has been reached. Start: 01/01/19… | Details → |
| 119 | Paid on adjunctive treatment basis only. Condition not accepted. | Details → |
| 119 | Item has met maximum limit for this time period. Payment already made for same/simila… | Details → |
| 120 | Inc in Part A The services billed on this claim are considered directly related to an… | Details → |
| 120 | Patient is covered by a managed care plan. Start: 01/01/1995 | Stop: 06/30/2007 Not… | Details → |
| 120 | Denied. The date of service is required. Submit bill only when service has been compl… | Details → |
| 121 | Need mod Component of comprehensive procedure that would be allowed if appropriate mo… | Details → |
| 121 | Indemnification adjustment - compensation for outstanding member responsibility. Sta… | Details → |
| 121 | Not paid. Provider name and/or number is missing or invalid. | Details → |
| 122 | T or S Medical visit on same day as a type T or S procedure without modifier 25. | Details → |
| 122 | Psychiatric reduction. Start: 01/01/1995 | Details → |
| 122 | History adjustment due to consolidation of claim numbers. | Details → |
| 123 | Rev Code Please resubmit with corrected Revenue Code. | Details → |
| 123 | Payer refund due to overpayment. Start: 01/01/1995 | Stop: 06/30/2007 Notes: Refer … | Details → |
| 123 | Denied. This service is not payable in advance. | Details → |
| 124 | Mileage Mileage included in base rate. | 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.