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 |
|---|---|---|
| 278 | Performance program proficiency requirements not met. (Use only with Group Codes CO o… | Details → |
| 278 | Denied. L&I notification of cancellation was provided within 3 days of examination. | Details → |
| 279 | Services not provided by Preferred network providers. Usage: Use this code when there… | Details → |
| 279 | Deduction taken for bills previously paid on a claim which has subsequently been reje… | Details → |
| 280 | Claim received by the medical plan, but benefits not available under this plan. Submi… | Details → |
| 280 | Denied. Claim number billed is not active. Call 1-800-831-5227 to confirm the claim n… | Details → |
| 281 | Deductible waived per contractual agreement. Use only with Group Code CO. Start: 07/… | Details → |
| 281 | Denied. The date of service is prior to the date of injury. | Details → |
| 282 | The procedure/revenue code is inconsistent with the type of bill. Usage: Refer to the… | Details → |
| 282 | Your bill must be held pending adjudication of this claim. | Details → |
| 283 | Attending provider is not eligible to provide direction of care. Start: 11/01/2017 | Details → |
| 283 | Bill did not exceed L&I high cost outlier thresholds. | Details → |
| 284 | Precertification/authorization/notification/pre-treatment number may be valid but doe… | Details → |
| 284 | DRG cannot be assigned. Check age, sex, patient status, procedure & diagnosis codes &… | Details → |
| 284 | Precertification/authorization/notification/pre-treatment number may be valid but doe… | Details → |
| 285 | Appeal procedures not followed Start: 11/01/2017 | Details → |
| 285 | Not referred by the attending physician of record and L&I authorization not obtained. | Details → |
| 286 | Appeal time limits not met Start: 11/01/2017 | Details → |
| 286 | Denied. The CPT code for the surgical procedure performed must be listed on the billi… | Details → |
| 287 | Referral exceeded Start: 11/01/2017 | Details → |
| 287 | Denied. This is an electronic bill. The clearinghouse is not authorized to submit bil… | Details → |
| 288 | Referral absent Start: 11/01/2017 | Details → |
| 288 | Bill returned to provider with new provider application form. Previous application wa… | Details → |
| 289 | Services considered under the dental and medical plans, benefits not available. Star… | Details → |
| 289 | Please note the provider number. Use this number to bill for rehabilitation unit serv… | Details → |
| 290 | Claim received by the dental plan, but benefits not available under this plan. Claim … | Details → |
| 290 | Denied. Include outpatient charges on the inpatient bill to be resubmitted to L&I. | Details → |
| 291 | Claim received by the medical plan, but benefits not available under this plan. Claim… | Details → |
| 291 | Denied. Explanation of -52 modifier not supplied as per contract requirements. Rebill… | Details → |
| 292 | Claim received by the medical plan, but benefits not available under this plan. Claim… | Details → |
| 292 | Denied. Our records do not show the provider and group number on bill as related. Cal… | Details → |
| 293 | Payment made to employer. Start: 05/01/2018 | Details → |
| 293 | Denied. These services were not billed in accordance with contract. Rebill per contra… | Details → |
| 294 | Payment made to attorney. Start: 11/01/2017 | Details → |
| 294 | Denied. Dates of service must be itemized. Correct and resubmit. | Details → |
| 295 | Pharmacy Direct/Indirect Remuneration (DIR) Start: 03/01/2018 | Details → |
| 295 | Injured worker reimbursement bill returned to injured worker due to invalid claim num… | Details → |
| 296 | Precertification/authorization/notification/pre-treatment number may be valid but doe… | Details → |
| 296 | Injured worker reimbursement denied by L&I due to invalid claim number and no injured… | Details → |
| 297 | Claim received by the medical plan, but benefits not available under this plan. Submi… | Details → |
| 297 | Denied. Dental procedure code is missing or is not a valid 1987 American Dental Assoc… | Details → |
| 298 | Claim received by the medical plan, but benefits not available under this plan. Claim… | Details → |
| 298 | This payment is due to the hospital discount applied to your audit refund. | Details → |
| 299 | The billing provider is not eligible to receive payment for the service billed. Star… | Details → |
| 299 | Denied. As of July 1990, this revenue code is not a valid Washington State code. | Details → |
| 300 | Claim received by the Medical Plan, but benefits not available under this plan. Claim… | Details → |
| 300 | Services deleted were rendered after or during period of claim closure. | Details → |
| 301 | Claim received by the Medical Plan, but benefits not available under this plan. Submi… | Details → |
| 301 | Denied. The bill/report submitted was illegible. Information must be clearly printed … | Details → |
| 301 | Admit Hour Please resubmit with a valid admit hour. | Details → |
| 302 | Precertification/notification/authorization/pre-treatment time limit has expired. St… | Details → |
| 302 | Unable to process. Submit bill directly to L&I on the appropriate bill form. | Details → |
| 302 | Bill Type Please resubmit claim with appropriate bill type for inpatient procedure. | Details → |
| 303 | Prior payer's (or payers') patient responsibility (deductible, coinsurance, co-paymen… | Details → |
| 303 | Denied. This claim has been suspended and no benefits are payable during suspended ti… | Details → |
| 303 | Multiple NPI Our data indicates this claim has multiple Rendering NPI Numbers. Please… | Details → |
| 304 | Claim received by the medical plan, but benefits not available under this plan. Submi… | Details → |
| 304 | Denied. This service is not authorized. | Details → |
| 304 | Inpt Proc Inpatient Procedure | Details → |
| 305 | Claim received by the medical plan, but benefits not available under this plan. Claim… | 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.