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 |
|---|---|---|
| 839 | Denied for audit. Utilization review (UR) vendor will be contacting you regarding thi… | Details → |
| 840 | System resource error. Bill not processed. Resubmit. | Details → |
| 841 | System resource error (claimant eligibility). Bill not processed. | Details → |
| 842 | Denied for audit. EBP Health Plans will be contacting you regarding this bill. Do not… | Details → |
| 843 | System resource error (provider eligibility). Bill not processed. | Details → |
| 844 | Denied. This must be rebilled on miscellaneous or CMS-1500 bill form. | Details → |
| 845 | Denied. NDC obsolete or expired for date RX filled. Verify correct NDC used. Rebill i… | Details → |
| 846 | Denied. Prescribing provider number required when generic substitution not allowed. | Details → |
| 847 | Automated multi-channel test(s) paid at maximum allowed for unduplicated tests perfor… | Details → |
| 848 | Denied. Lab tests for service date must all be billed on one ICN. Send adjustment for… | Details → |
| 849 | System cannot determine pricing method. Submit manual bill. | Details → |
| 850 | In the future, please list the individual provider number as well as the clinic provi… | Details → |
| 851 | Denied. Payable only if lab test performed on inpatient basis. | Details → |
| 852 | Denied. Complex fees not payable in conjunction with single examiner examinations. | Details → |
| 853 | Microfiche handling payable only once per exam assignment. | Details → |
| 854 | Bill not processed. System error. Submit manual bill. | Details → |
| 855 | Bill not processed. Provider on review. Submit manual bill. | Details → |
| 856 | Denied. Surgery CPT for same DOS must be on one bill. Send adjustment to ICN (Interna… | Details → |
| 857 | Denied. This Bill was in direct entry suspense file for over 180 days and has become … | Details → |
| 858 | System resource error (drug file). Bill not processed. | Details → |
| 859 | Denied. Rebill with a copy of manufacturer's warranty/invoice showing cost, warranty … | Details → |
| 860 | Invalid data removed from prior authorization (PA) field. Leave blank if not require… | Details → |
| 861 | Denied. There is no employer/employee relationship. | Details → |
| 862 | Denied. Travel not authorized on pension claims with or without a treatment order. | Details → |
| 863 | Denied. Bill submitted without prior authorization. Call utilization review (UR) vend… | Details → |
| 864 | Allowed amt. Is $0.00. Immunobiologic is distributed at no cost by Centers for Diseas… | Details → |
| 865 | Denied. Chart notes required for service billed. No chart notes received. | Details → |
| 866 | Denied. Call utilization review (UR) vendor 800-541-2894 to be reviewed. Rebill when … | Details → |
| 867 | Decision made by L&I Office of the Medical Director to pay for noncovered services. | Details → |
| 868 | Denied. 10 digit prior authorization number required, but missing from your bill. | Details → |
| 869 | Item paid. Your -99 modifier was for payment and information modifiers. Changed to pa… | Details → |
| 870 | Denied. Date of service on bill does not match the review date or report date. | Details → |
| 871 | Denied. Submit your bill to Department of Energy (509-376-1416). | Details → |
| 872 | Effective DOS 7/1/00 providers must use 00100-01999 to bill for services paid with ba… | Details → |
| 873 | Procedure 99080 for narrative report only payable every 60 days unless specifically r… | Details → |
| 874 | Denied. Prior authorization was not obtained. Claim manager has denied. | Details → |
| 875 | You cannot use your clinic provider number to bill. Please rebill using the correct p… | Details → |
| 876 | Mileage has been reduced. Mileage over 50 miles one way needs prior approval. | Details → |
| 877 | Claim closed during part of date span. Call 1-800-831-5227 for claim closure informat… | Details → |
| 878 | Fluoroscopy must be used when performing this procedure. | Details → |
| 879 | Denied. Diagnosis/procedure not authorized on treatment order. | Details → |
| 880 | Denied. Only 1 unit of service allowed per claim. | Details → |
| 881 | Denied. Rebill to Dept. of L & I, Self Ins. Attn: Bankrupt Desk, P.O. Box 44892, Oly,… | Details → |
| 882 | Denied. Type service/procedure code is invalid. Refer to our current fee schedule for… | Details → |
| 883 | Repayment made to provider. L&I has already done an adjustment to cover your account. | Details → |
| 884 | Refund is being returned. Generally accident report, initial visit & necessary tests … | Details → |
| 885 | Ambulatory Surgery Center (ASC) service paid at the lesser; 100% fee schedule or bill… | Details → |
| 886 | Ambulatory Surgery Center (ASC) service paid at the lesser; 50% fee schedule or bille… | Details → |
| 887 | Ambulatory Surgery Center (ASC) paid at the lesser; 25% fee schedule or billed charge… | Details → |
| 888 | Denied. Resubmit bill with required copy of approved prejob/job modification applicat… | Details → |
| 889 | Denied. Ambulatory Surgery Center (ASC) procedures for service date must all be bille… | Details → |
| 890 | Denied. The 1st procedure code modifier in M1 is invalid for this provider type. | Details → |
| 891 | Denied. Fluoroscopy not billed and place of service indicates non-accredited facility… | Details → |
| 893 | Denied. The requested medical records have not been received. | Details → |
| 894 | Authorized as one-time only, per claim manager. | Details → |
| 895 | Per WAC 296-20-1103 travel only allowed from injured worker's home to nearest point o… | Details → |
| 896 | Denied. Reimbursement to pickup prescriptions/refills is not an allowed travel expens… | Details → |
| 897 | Denied per provider request. | Details → |
| 898 | Too many exceptions for your bill to process. Break this billing down to 7 line items… | Details → |
| 899 | Too many errors for bill payment. Refer to Fee Schedule/Bill Instruction packet and r… | 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.