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 |
|---|---|---|
| D20 | Claim/Service missing service/product information. Start: 01/01/1995 | Stop: 06/30/2… | Details → |
| D20 | Denied. Day supply exceeds L&I's 30 day supply limit. | Details → |
| D21 | This (these) diagnosis(es) is (are) missing or are invalid Start: 01/01/1995 | Stop:… | Details → |
| D21 | Denied. Procedure is for unclassified injectable drugs. Not payable for oral drugs. | Details → |
| D22 | Reimbursement was adjusted for the reasons to be provided in separate correspondence.… | Details → |
| D22 | Denied. Prescription filled after date of pension and treatment order does not includ… | Details → |
| D23 | This dual eligible patient is covered by Medicare Part D per Medicare Retro-Eligibili… | Details → |
| D23 | Denied. L&I does not pay for brand drugs when a generic is available and substitution… | Details → |
| D24 | Name Submitted on prescription bill does not match injured worker name on file for th… | Details → |
| D25 | Denied. L&I does not pay for repackaged drugs. | Details → |
| D26 | Denied. Day supply for opioids exceeds L&I's 28 day supply limit. | Details → |
| D27 | Denied. Day supply exceeds L&I's 90 day supply limit for mail order prescriptions. | Details → |
| D28 | Denied. Claim not authorized for mail order prescription. Prescription filled by mail… | Details → |
| D3 | Claim/service denied because information to indicate if the patient owns the equipmen… | Details → |
| D4 | Claim/service does not indicate the period of time for which this will be needed. St… | Details → |
| D5 | Claim/service denied. Claim lacks individual lab codes included in the test. Start: … | Details → |
| D6 | Claim/service denied. Claim did not include patient's medical record for the service.… | Details → |
| D7 | Claim/service denied. Claim lacks date of patient's most recent physician visit. Sta… | Details → |
| D8 | Claim/service denied. Claim lacks indicator that 'x-ray is available for review.' St… | Details → |
| D80 | Denied. Tooth number is denied under this claim. | Details → |
| D9 | Claim/service denied. Claim lacks invoice or statement certifying the actual cost of … | Details → |
| E00 | Denied. Procedure code requires RR or NU modifier. See HCPCS section of Medical Aid R… | Details → |
| E01 | Further rental is denied. Purchase of new DME is required. Retrieve rental DME and re… | Details → |
| E02 | Further rental is denied. There is no medical certification on file for continued use… | Details → |
| E03 | Twelve (12) months of rental payments have been made. Equipment is now owned by the i… | Details → |
| E04 | Further rental is denied. There is no medical certification on file for continued use… | Details → |
| E05 | Denied. These services are not payable during the DME warranty period. | Details → |
| E06 | Denied. A warranty is required for all DME repair. Please send warranty and rebill. | Details → |
| E07 | Maximum units were reviewed by L&I and no additional units will be paid. | Details → |
| E08 | Bill Denied with 6 DE due to possible EDI edit functionality issues. | Details → |
| E09 | This payment is a reimbursement for WA Stay-At-Work Program. | Details → |
| E10 | This claim denied as a duplicate. COHE Admin Fee processed under the workers accepted… | Details → |
| E11 | Further rental denied, purchase required. Retrieve rental and replace with new pump. … | Details → |
| E12 | L&I allows 4 months rental and requires purchase on the 5th month. | Details → |
| H00 | EDI formatting error: This billing is denied/rejected - The second EOB details the er… | Details → |
| H01 | Invalid workers' compensation pay-to provider number. | Details → |
| H02 | Missing workers' compensation billing provider number. | Details → |
| H03 | Invalid workers' compensation billing provider number. | Details → |
| H04 | Submitting transaction is not identified as a workers' compensation billing. | Details → |
| H05 | Invalid/missing workers' compensation claim number (subscriber identification). | Details → |
| H06 | Invalid transaction type code (must be chargeable). | Details → |
| H07 | Invalid transaction type identification (identified as draft/pilot). | Details → |
| H08 | Invalid claim frequency type code (adjustment/replacement/void not allowed). | Details → |
| H09 | Line item maximum exceeded (see EDI companion guide). | Details → |
| H10 | Missing workers' compensation pay-to provider number. | Details → |
| H11 | Missing workers' compensation rendering provider number. | Details → |
| H12 | Invalid workers' compensation rendering provider number. | Details → |
| H13 | Denied. The procedure code is incorrect for the report requested and/or received. Ref… | Details → |
| H14 | Denied. This report was not requested by L&I. Please bill the party who requested thi… | Details → |
| H15 | Report of Accident (ROA) not payable to a physician assistant because this claim does… | Details → |
| H16 | Suspended. Claim number is missing or invalid on bill. Call 1-800-831-5227 to confirm… | Details → |
| H17 | Denied. No audiogram was received. | Details → |
| H18 | Denied. ICD-10 diagnosis submitted prior to ICD-10 effective date. | Details → |
| H19 | Denied. ICD-10 procedure code submitted prior to ICD-10 effective date. | Details → |
| H21 | The payee provider's NPI is either invalid or is not registered. Call Provider Crede… | Details → |
| H22 | Invalid NPI billing provider number. The submitted NPI is not on file or is not assoc… | Details → |
| H23 | The service provider's NPI is invalid or is not registered. Call Provider Credentiali… | Details → |
| H24 | We are unable to determine the payee. Call Provider Credentialing at 360-902-5140. | Details → |
| H25 | We are unable to determine the provider of service with the NPI provided. Call Provid… | Details → |
| H26 | The payee's NPI is invalid (format error). Please correct and resubmit your bill. | 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.