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 |
|---|---|---|
| 305 | This transaction has been taken to correct the file per a special request. | Details → |
| 305 | Dialysis Claim lacking CBSA Dialysis claims require a CBSA. Please resubmit. | Details → |
| 306 | Current charges are being processed. Submit an itemized billing for the balance forwa… | Details → |
| 306 | Invalid CPT for benefit This CPT code is not valid for this benefit. Resubmit claim w… | Details → |
| 307 | Corrections to this bill (ICN) have been made per your request. | Details → |
| 307 | RAP received RAP received. Payment for this episode has been paid. | Details → |
| 308 | Denied. This service is not an authorized vocational expense. | Details → |
| 308 | Mbr not approved for in home podiatry. This member is not approved to receive podiatr… | Details → |
| 309 | Charges previously paid for this date. If this is not a duplicate submit adjustment t… | Details → |
| 309 | Inpt claim with same DOS as ER Inpatient claim/auth exists for same DOS as ER claim. | Details → |
| 310 | Denied. Service was before or after the dates authorized for the pain clinic program. | Details → |
| 310 | Code not recognized by OPPS Codes not recognized by OPPS when submitted on an outpati… | Details → |
| 311 | Denied. A pain program has not been authorized for this injured worker. | Details → |
| 311 | Operating Physician required Operating Physician Information Required. | Details → |
| 312 | This transaction cancels interim payment credit balance for this provider number. | Details → |
| 312 | HomeHealth claim for prev episode not submitted Payment Denied. Previous Episode Fina… | Details → |
| 313 | This transaction reflects interim payment credit balance refund and corrects year to … | Details → |
| 313 | HIPPS/RUGS charges not equal to $0 HIPPS/RUGS billed charges should equal zero. | Details → |
| 314 | This transaction reduces the interim payment credit balance for this provider number. | Details → |
| 314 | Invalid RAP Invalid/Incorrect RAP submitted for this episode. Valid/Corrected RAP mus… | Details → |
| 315 | This travel related expense is denied in accordance with L&I policy. | Details → |
| 315 | Submit TOB 328 to cancel paid final claim Unable to cancel RAP because FINAL has PAID… | Details → |
| 316 | This is a history adjustment to correct an error in firm number and class. | Details → |
| 316 | Rendering provider name required Individual provider name needed. Please resubmit wit… | Details → |
| 317 | Denied. The principal, admitting or patient's reason for visit diagnosis code denotes… | Details → |
| 317 | Max rental period exceeded Based on Medicare pricing guidelines, the rental units hav… | Details → |
| 318 | Denied. Office visit includes manipulation. | Details → |
| 318 | Attending physician NPI missing Attending Physician with identifying NPI is a require… | Details → |
| 319 | Revenue code, cover dates or prior authorization (PA) number are incompatible with th… | Details → |
| 319 | TOB 327 for denied claim Unable to process 327 bill type for a previously DENIED clai… | Details → |
| 320 | Note claim number and your provider number. These are required on all bills sent to t… | Details → |
| 320 | Date required for line item BILL WITH SPECIFIC DATES | Details → |
| 321 | Revenue code(s) invalid for date(s) of service billed. Rebill with correct codes. | Details → |
| 321 | Resubmitted Claim Duplicate of claim in review | Details → |
| 322 | Denied. Service is in violation of specific restrictions imposed by the Department of… | Details → |
| 322 | Invalid date INVALID DATE OF SERVICE | Details → |
| 323 | This procedure code wasn't valid at time of service. Refer to the latest fee schedule… | Details → |
| 323 | Cosurgeon not allowed Co-surgeon not allowed | Details → |
| 324 | Denied. Bill and reports indicate services were provided for a new injury/incident. | Details → |
| 324 | Episode canceled Bill type 328 received; episode and associated claims cancelled. | Details → |
| 325 | An adjusted bill paid without deducting the original bill. This is a corrective actio… | Details → |
| 325 | Pay to provider does not match Bravo affiliations The name in box 33 does not match w… | Details → |
| 326 | Denied. This service or drug is not allowed for treatment of industrial injuries. | Details → |
| 326 | Group TIN submitted The Tax ID submitted is associated to a Group. Please resubmit th… | Details → |
| 327 | Denied. No report received from the attending doctor to justify authorization of this… | Details → |
| 327 | Signature does not match what is on file The signature on the claim does not match th… | Details → |
| 328 | Denied. Injured worker age and/or sex invalid for this procedure or diagnosis. | Details → |
| 328 | Submit to Part D Please submit to your Pharmacy Program. | Details → |
| 328 | Received. No matching claim found for cancellation request. Cancellation request must… | Details → |
| 329 | This adjustment is the result of an independent audit of charges for the service(s). | Details → |
| 329 | Noncovered OON dental Dental Services Performed by Non-Par Specialists are Not Covere… | Details → |
| 330 | Denied. This procedure was not included as a part of the approved program for this pr… | Details → |
| 330 | E code cannot be principal DX E code cannot be used as principal diagnosis. | Details → |
| 331 | Please refer to the billing instructions provided by L&I. | Details → |
| 331 | Payment for non Medicare covered services Additional payment for services not provide… | Details → |
| 332 | Denied. The type of service and/or procedure is not authorized for this provider type… | Details → |
| 332 | Place of service not covered under OPPS Code indicates a site of service not included… | Details → |
| 333 | Do not bill several procedures/diagnoses/dates in one line. These will be denied in t… | Details → |
| 333 | Service unit out of range for procedure Service unit out of range for procedure. | Details → |
| 334 | These services were not medically necessary.CO 50 | 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.