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 |
|---|---|---|
| 464 | Per medical review the billed discharge status was corrected and payment made accordi… | Details → |
| 465 | Please rebill ambulance service on a CMS-1500 form using your professional service pr… | Details → |
| 466 | Denied. Please submit request for interest including justification, to MIPS at mail i… | Details → |
| 467 | Denied. Use code 97201 to bill for added service or time. Submit an adjustment to thi… | Details → |
| 468 | Denied. This service is not payable when billed with codes 97124/97125 or 97200/97201… | Details → |
| 469 | This request for interest payment has been forwarded to our fiscal unit for payment. | Details → |
| 470 | Denied. Please resubmit this inpatient bill with the required attachments. | Details → |
| 471 | Denied. Revenue code needs CPT/HCPCS procedure code for APG assignment - procedure co… | Details → |
| 472 | Denied per your affidavit stating that you were not entitled to payment for this serv… | Details → |
| 473 | Denied. Procedure 99025 payable only in conjunction with starred (*) CPT surgical cod… | Details → |
| 474 | There was no notification of this admit. The bill is referred to AUGMED for possible … | Details → |
| 475 | Returned. The provider number and the name on the bill do not match. | Details → |
| 476 | Thank you. Your effort to provide information needed to process this transaction is a… | Details → |
| 477 | Denied. Units of service are invalid. Please rebill with correct unit/hours. | Details → |
| 478 | Denied. Missed appointment was cancelled 3 or more days prior to the appointment date… | Details → |
| 479 | POAC retroactively adjusted to conform with July 1, 1993 effective date. Refer to 6/1… | Details → |
| 480 | As of last cut-off date, this bill was on the provider's direct entry suspense file. | Details → |
| 481 | Denied. Sixth diagnosis code is not sufficiently specific. | Details → |
| 482 | Denied. Seventh diagnosis code is not sufficiently specific. | Details → |
| 483 | Denied. Eighth diagnosis code is not sufficiently specific. | Details → |
| 484 | Denied. Ninth diagnosis code is not sufficiently specific. | Details → |
| 485 | Denied. Sixth diagnosis denotes a non-industrial condition or is not sufficiently spe… | Details → |
| 486 | Denied. Seventh diagnosis denotes a non-industrial condition or is not sufficiently s… | Details → |
| 487 | Denied. Eighth diagnosis denotes a non-industrial condition or is not sufficiently sp… | Details → |
| 488 | Denied. Ninth diagnosis denotes a non-industrial condition or is not sufficiently spe… | Details → |
| 489 | Denied. Sixth ICD diagnosis code is invalid for first date of service. | Details → |
| 490 | Denied. Seventh ICD diagnosis code is invalid for first date of service. | Details → |
| 491 | Denied. Eighth ICD diagnosis code is invalid for first date of service. | Details → |
| 492 | Denied. Ninth ICD diagnosis code is invalid for first date of service. | Details → |
| 493 | Denied. Revenue code needs CPT/HCPCS procedure code for APG assignment - procedure co… | Details → |
| 495 | Denied. Services not requested. | Details → |
| 497 | Employer reimbursed by hand warrant for payment of this bill. | Details → |
| 498 | An adjustment to this bill is in process and will appear on a future remittance advic… | Details → |
| 499 | Denied. Procedure previously paid for date(s) of service. Submit adjustment to paid b… | Details → |
| 500 | Date(s) of service on this bill have been changed to correspond with the retraining a… | Details → |
| 501 | Denied. Service was rendered outside of the authorized time period. | Details → |
| 502 | Payment made at amount authorized for this retraining procedure code. | Details → |
| 503 | Denied. The legal maximum of $4000 for retraining has been expended. | Details → |
| 504 | Approval of additional funds allows payment of previously denied or reduced bill. | Details → |
| 505 | Denied. This revenue code is invalid for outpatient service. | Details → |
| 506 | Paid at a reduced rate. Procedure not authorized on an inpatient basis. | Details → |
| 507 | Denied. Retraining plan not approved on this claim. | Details → |
| 508 | Please bill modifier -27 with any dates of service prior to 9-1-93. | Details → |
| 509 | Pharmacy submitted injured worker reimbursement. Injured worker will be reimbursed fo… | Details → |
| 510 | Denied. No balance remains in approved funds for this procedure. Contact vocational c… | Details → |
| 511 | Denied. L&I records do not contain approval of retraining services for this claim. | Details → |
| 512 | Prescription bill reversal submitted by pharmacy. | Details → |
| 513 | Prescribing provider not authorized for this claim. Bill not paid. | Details → |
| 514 | Denied. Drug refill too soon. | Details → |
| 515 | Accident claim not yet allowed. Point of Sale bill denied pending claim allowance. | Details → |
| 516 | Denied. Services not requested. | Details → |
| 550 | Please read your remittance advice newsletter dated 6-08-93 re: name & number do not … | Details → |
| 555 | Tax computation adjusted and paid to reflect payment of 14.1 percent multiplied by CH… | Details → |
| 556 | Denied. L&I does not accept minus charges. | Details → |
| 559 | Action is being taken. Do not send rebill, adjustment or appeal until you receive not… | Details → |
| 560 | Injured worker's accident rejected by L&I State Fund and service not authorized. Cont… | Details → |
| 561 | Denied. Surgical tray is not payable with the procedure billed. | Details → |
| 562 | Avoid possible bill rejection. Please contact your nearest service location for curre… | Details → |
| 566 | Manually priced due to other surgery bills with same date. Modifiers are ranked withi… | Details → |
| 580 | Denied. Service payable at intervals of no less than 6 months. | 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.