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Denial code lookup.
What it means, how to fix it.
Search the claim adjustment reason codes (CARC) and remark codes (RARC) practices see most, in plain English, with the usual causes and fixes.
64 of 64 codes
- PR-1Deductible amountCARC
- PR-2Coinsurance amountCARC
- PR-3Co-payment amountCARC
- CO-4Procedure code inconsistent with the modifier, or a required modifier is missingCARC
- CO-5Procedure code or bill type inconsistent with the place of serviceCARC
- CO-6Procedure inconsistent with the patient's ageCARC
- CO-8Procedure code inconsistent with the provider type or specialtyCARC
- CO-11Diagnosis inconsistent with the procedureCARC
- CO-15Authorization number missing, invalid or does not applyCARC
- CO-16Claim lacks information or has a billing errorCARC
- CO-18Exact duplicate claim or serviceCARC
- CO-19Work-related injury: bill workers' compensationCARC
- CO-22Care may be covered by another payer (coordination of benefits)CARC
- OA-23Impact of prior payer's adjudicationCARC
- CO-24Covered under a capitation or managed care agreementCARC
- CO-26Expenses incurred before coverage beganCARC
- CO-27Expenses incurred after coverage endedCARC
- CO-29Time limit for filing has expiredCARC
- CO-31Patient cannot be identified as an insuredCARC
- CO-35Lifetime benefit maximum reachedCARC
- CO-40Charges do not meet criteria for emergency or urgent careCARC
- CO-45Charge exceeds the fee schedule or contracted amountCARC
- CO-49Routine or preventive service not coveredCARC
- CO-50Not medically necessary (per the payer)CARC
- CO-55Experimental or investigationalCARC
- CO-58Rendered in an inappropriate or invalid place of serviceCARC
- CO-59Processed under multiple or concurrent procedure rulesCARC
- CO-96Non-covered chargeCARC
- CO-97Included in the payment for another service (bundled)CARC
- CO-109Not covered by this payer: send to the correct payerCARC
- CO-119Benefit maximum for the period reachedCARC
- CO-129Prior processing information appears incorrectCARC
- CO-140Patient or insured ID and name do not matchCARC
- CO-146Diagnosis was invalid for the date of serviceCARC
- CO-151Information does not support this many services or this frequencyCARC
- CO-167Diagnosis is not coveredCARC
- CO-170Not paid when performed or billed by this type of providerCARC
- CO-181Procedure code was invalid on the date of serviceCARC
- CO-185Rendering provider not eligible to perform the serviceCARC
- CO-197Precertification, authorization or notification absentCARC
- CO-198Precertification or authorization exceededCARC
- CO-204Not covered under the patient's current benefit planCARC
- CO-226Information requested from the provider was not providedCARC
- CO-227Information requested from the patient was not providedCARC
- CO-236Procedure combination not compatible on the same day (NCCI)CARC
- CO-242Services not provided by network or primary care providersCARC
- CO-252An attachment or other documentation is requiredCARC
- CO-B7Provider not certified or eligible to be paid on this date of serviceCARC
- CO-B15Requires a qualifying service that was not received or coveredCARC
- CO-A1Claim or service deniedCARC
- N290Missing or invalid rendering provider identifierRARC
- N286Missing or invalid referring provider identifierRARC
- MA130Incomplete or invalid claim: unprocessable, no appeal rightsRARC
- M51Missing, incomplete or invalid procedure codeRARC
- M76Missing, incomplete or invalid diagnosisRARC
- N130Consult plan benefit documents for restrictionsRARC
- M127Missing patient medical record for this serviceRARC
- MA04Secondary payment needs primary payer informationRARC
- N30Patient ineligible for this serviceRARC
- N20Service not payable with another service on the same dateRARC
- M80Not covered when performed in the same session as another serviceRARC
- N56Procedure code not correct or valid for the services or date billedRARC
- N382Missing or invalid patient identifierRARC
- N522Duplicate of a claim processed as a crossover claimRARC
How to read a denial code
A denial on an ERA or EOB has two parts. The group code says who is responsible for the amount: CO (contractual obligation, you cannot bill the patient), PR (patient responsibility), OA (other adjustment) or PI (payer-initiated reduction). The reason code (CARC) says why. A remark code (RARC) often adds the specific detail. CO-16 with N290, for example, means the claim was missing information, and the missing item was the rendering provider's NPI.
These are plain-English summaries written by GetMax to help you act quickly. For the official wording, see the code lists published by X12 at x12.org/codes.
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