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 |
|---|---|---|
| R13 | Denied. Date of service does not match first treatment date on Report of Accident (RO… | Details → |
| S00 | Denied. Procedure code 1207M must be billed and paid before 1215M can be considered f… | Details → |
| S01 | Denied. The structured settlement agreement does not include a provision for medical … | Details → |
| S02 | Paid per the structured settlement agreement. | Details → |
| S03 | Denied. The structured settlement agreement unit has denied this service(s). | Details → |
| S04 | Denied application pending. Contact Provider Credentialing & Compliance at 360-902-51… | Details → |
| S07 | Denied. No network status for date of service billed. Contact Provider Credentialing … | Details → |
| S08 | Denied. Network status is non-participating, only initial visit (IV) is payable. | Details → |
| S09 | Denied. 'This exam date' from the report of accident (which is the initial visit date… | Details → |
| S10 | Denied. Provider is not eligible for payment for date of service billed. | Details → |
| S13 | Denied. Date span overlaps multiple network statuses. Rebill one date of service per … | Details → |
| S14 | Denied. Prescribing provider is not eligible to prescribe for date of service billed. | Details → |
| S15 | Denied. Date of serivce is before 'This Exam Date' (which is they intital visit date)… | Details → |
| T18 | Processed per WAC 296-20-1103. This line item has been reduced by 30 miles roundtrip. | Details → |
| T19 | Denied. Treatment is available within 15 miles one way. Travel expense is not payable… | Details → |
| T20 | Denied. Only payable when you must travel more than 15 miles one way. | Details → |
| T21 | Denied. Only authorized travel over 15 miles one way to nearest available treatment i… | Details → |
| T22 | Processed per WAC 296-20-1103. This one way trip has been reduced by 15 miles. | Details → |
| W1 | Workers' compensation jurisdictional fee schedule adjustment. Note: If adjustment is … | Details → |
| W2 | Payment reduced or denied based on workers' compensation jurisdictional regulations o… | Details → |
| W3 | The Benefit for this Service is included in the payment/allowance for another service… | Details → |
| W4 | Workers' Compensation Medical Treatment Guideline Adjustment. Start: 09/30/2012 | St… | Details → |
| W5 | Medical provider not authorized/certified to provide treatment to injured workers in … | Details → |
| W6 | Referral not authorized by attending physician per regulatory requirement. Start: 06… | Details → |
| W7 | Procedure is not listed in the jurisdiction fee schedule. An allowance has been made … | Details → |
| W8 | Procedure has a relative value of zero in the jurisdiction fee schedule, therefore no… | Details → |
| W9 | Service not paid under jurisdiction allowed outpatient facility fee schedule. Start:… | Details → |
| Y1 | Payment denied based on Medical Payments Coverage (MPC) or Personal Injury Protection… | Details → |
| Y2 | Payment adjusted based on Medical Payments Coverage (MPC) or Personal Injury Protecti… | Details → |
| Y3 | Medical Payments Coverage (MPC) or Personal Injury Protection (PIP) Benefits jurisdic… | Details → |
| Z01 | Payment expended from 1st year retraining plan. | Details → |
| Z02 | Payment expended from 2nd year retraining plan. | Details → |
| Z03 | Processed due to tools/equipment returned to L&I. | Details → |
| Z04 | Returned tools/equipment reissued. | Details → |
| Z05 | Payment expended from Option 1 Retraining Plan. | Details → |
| Z06 | Payment expended from Option 2 Retraining Plan. | Details → |
| Z20 | Denied. All or part of your service is beyond the 14-day grace period allowed for the… | Details → |
| Z21 | Adjudicated per instructions from the Vocational Services Specailists. | Details → |
| 1 | Deductible Amount Start: 01/01/1995 | Details → |
| 1 | Denied. Care beyond first 20 visits or 60 days requires authorization. | Details → |
| 1 | Services after auth end The services were provided after the authorization was effect… | Details → |
| 2 | Coinsurance Amount Start: 01/01/1995 | Details → |
| 2 | Denied. Report of Accident (ROA) payable once per claim. Previous payment has been ma… | Details → |
| 2 | Services prior to auth start The services were provided before the authorization was … | Details → |
| 3 | Co-payment Amount Start: 01/01/1995 | Details → |
| 3 | Initial office visit payable 1 time only for same injured worker/provider/diagnosis. | Details → |
| 3 | No auth on file There is no authorization on file for these services. | Details → |
| 4 | The procedure code is inconsistent with the modifier used. Usage: Refer to the 835 He… | Details → |
| 4 | Denied. Physical therapy by the attending doctor is limited to 6 treatments. | Details → |
| 4 | HCPCS code is inconsistent with modifier used or required modifier is missing | Details → |
| 4 | Max Days This claim exceeds the maximum allowed days per benefit period | Details → |
| 5 | The procedure code/type of bill is inconsistent with the place of service. Usage: Ref… | Details → |
| 5 | Denied. Physical therapy beyond the first 12 treatments requires authorization. | Details → |
| 5 | The procedure code/bill type is inconsistent with the place of service Missing/incom… | Details → |
| 5 | Not member Denied: No coverage effective at time of service. | Details → |
| 6 | The procedure/revenue code is inconsistent with the patient's age. Usage: Refer to th… | Details → |
| 6 | Rental has extended over 30 days. Only short term rental is allowed. | Details → |
| 6 | Benefit Day Limit Exceeded. Benefit Day Limit Exceeded. | Details → |
| 7 | The procedure/revenue code is inconsistent with the patient's gender. Usage: Refer to… | Details → |
| 7 | Denied. Facet joint injections are limited to 4 per injured worker. | 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.