DenialCode.com
Free Healthcare Billing Reference

Medical Denial Code
Lookup Tool

Instantly find explanations, causes, and resolution steps for every Claim Adjustment Reason Code (CARC) and Remark Code.

Popular: CO-16 CO-45 PR-1 CO-29 CO-4 CO-45 Remark Code
4,524+
Denial Codes
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Group Code Types
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2024
Updated CARC List
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What Are Denial Codes?

Claim Adjustment Reason Codes (CARC) explain why a payment differs from what was billed. Every 835 ERA and EOB uses these standardized codes.

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How to Use This Tool

Search any code or keyword above. Each page includes the full description, common causes, resolution steps, and appeal guidance.

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Remark Codes Too

Each denial code page also links to a dedicated Remark Code page — optimized for providers searching for ERA remark code context.

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Appeal Your Denial

Most denials are reversible. Our guides walk you through the correct steps to correct, resubmit, or formally appeal each denial type.

Claim Adjustment Reason Codes
Showing 4,524 codes — click any code for full explanation and resolution steps
Code Description View
1021Missing form A single case agreement referral form must accompany each claim submitte…Details →
1023Missing OP report Resubmit with OP report.Details →
1024Invalid discharge hour Invalid Discharge HourDetails →
1025ERAP payment Payment denied. Information on file indicates payment was made to anothe…Details →
1026Units billed exceeds auth The number of units billed exceeds the number of units auth…Details →
1027Refund received due to billing error Refund received due to billing errorDetails →
1028Refund Received resubmit to LifeSynch Refund Received resubmit to LifeSynchDetails →
1029Raytel and service location not in box 33 Please resubmit using Raytel's Tax ID and t…Details →
1030Invalid primary or admitting dx code Invalid primary or admitting diagnosis code � pl…Details →
1031Primary dx paired with secondary dx Primary Dx is not acceptable unless paired with a…Details →
1032Billable visit not appropriate level First billable visit not skilled at appropriate …Details →
1033Supply revcodes not on claim Provider billed HHPPS FINAL indicating Medical/Surgical …Details →
1034Revcode requires HCPCS, DOS and amount Revenue code 0274 requires an HCPCS code, the …Details →
1035Cancellation submitted prior to up/downcoding In order to bill new HHPPS HHRG code, a…Details →
1036Unable to adjust RAPS Unable to adjust RAPS. RAPS must be canceled and re-billed in o…Details →
1037No claim in std benefit period No claim in std benefit period before use of reserve d…Details →
1038Other agency responsible for payment Other agency may be responsible for paymentDetails →
1040Timely filing This claim was submitted after the filing deadline.Details →
1046Invalid specialty for svc Provider specialty invalid for service rendered.Details →
1049Resubmit to TX Mcaid , MCO not responsible for InP Submit Inpatient Acute Care Claims…Details →
1050MOOP This member has reached the max out-of-pocket amount for 2011. If cost-share in …Details →
1051Medicare not reimbursing procedure code This procedure code is not reimbursable throu…Details →
1052Not medically necessary Medical necessity not established for services rendered.Details →
1053Attendant Care Payment Based upon Participation Level, Attendant Care Enhanced Paymen…Details →
1054Resubmit with CMS rate sheet Resubmit claim with a CMS rate sheet.Details →
1055Cancellation recd, claim cancelled. The cancellation claim was received; claim was ca…Details →
1056327 recd; adjustment adjudicated TOB 327 received; adjustment adjudicated.Details →
1057Billed service to DMERC Service can only be billed to the DMERC.Details →
1058Denied for wrong surgery Claim detail denied due to wrong surgery performed on clientDetails →
1059Pending Rate Hearing State has not issued procedure code pricing. Claims will be repr…Details →
1060ICRS DRG audit Claim reversal is due to ICRS DRG audit.Details →
1061Resubmit with a DRG Please resubmit your claim with a DRG.Details →
1062Code is Included Services included per CPT Guidelines.Details →
1064CODE CHANGED PROCEDURE CODE CHANGED PER REVIEWDetails →
1065INCLUDED IN PRIMARY PROCEDURE INCLUDED IN PRIMARY PROCEDUREDetails →
1066PROCEDURE INAPPROPRIATELY CODED PROCEDURE INAPPROPRIATELY CODEDDetails →
1067NOT A COVERED SERVICE NOT A COVERED SERVICEDetails →
1068NOT A COVERED SERVICE FOR PROVIDER SPECIALTY NOT A COVERED SERVICE FOR PROVIDER SPECI…Details →
1069POST-OP FOLLOW-UP INCLUDED WITH GLOBAL FEE POST-OP FOLLOW-UP INCLUDED WITH GLOBAL FEEDetails →
1070E & M CODE LEVEL RECODED. E & M CODE LEVEL RECODED.Details →
1071RESUBMIT WITH SUPPORTING DOCUMENTATION RESUBMIT WITH SUPPORTING DOCUMENTATIONDetails →
1072MULTIPLE ENDOSCOPY RULES MULTIPLE ENDOSCOPY RULESDetails →
1073SURGEON AND SURGICAL ASSIST SURGEON AND SURGICAL ASSIST CANNOT BE THE SAME PROVIDERDetails →
1074ICD9 DOES NOT SUPPORT PROCEDURE THE ICD9 CODES ON THE CLAIM DO NOT SUPPORT THE BILLED…Details →
1075ONLY ONE E/M CODE ALLOWED PER DAY ONLY ONE E/M CODE ALLOWED PER DAYDetails →
1076INCORRECT MODIFIER INCORRECT MODIFIERDetails →
1077MULTIPLE ASSIST SURGEONS NOT ALLOWED MORE THAN ONE ASSISTANT SURGEON NOT ALLOWEDDetails →
1078INCLUDED IN E&M SERVICE INCLUDED IN E&M SERVICEDetails →
1079MUTUALLY EXCLUSIVE PROCEDURE MUTUALLY EXCLUSIVE PROCEDUREDetails →
1080ONLY ONE SERVICE ALLOWED PER COURSE OF TREATMENT. ONLY ONE SERVICE ALLOWED PER COURSE…Details →
1081ALLOWED AMOUNT GREATER THAN SUBMITTED AMOUNT ALLOWED AMOUNT GREATER THAN SUBMITTED AM…Details →
1082ADD-ON CODE WAS DENIED THE ADD-ON CODE WAS DENIED BECAUSE THE PRIMARY PROCEDURE WAS N…Details →
1083ADJUSTED UNITS ADJUSTED UNITS BECAUSE THEY EXCEEDED THE AMOUNT ALLOWEDDetails →
1084RECODED TO A GENERAL ANESTHESIA SERVICE CODE RECODED TO A GENERAL ANESTHESIA SERVICE …Details →
1085BLOOD COLLECTION INCLUDED IN LAB SERVICES BLOOD COLLECTION INCLUDED IN LAB SERVICESDetails →
1086SERVICE PROCESSED AS A BILATERAL PROCEDURE SERVICE PROCESSED AS A BILATERAL PROCEDUREDetails →
1087BILATERAL PROCEDURE INAPPROPRIATELY CODED BILATERAL PROCEDURE INAPPROPRIATELY CODEDDetails →
1088PROCEDURE BILATERAL IN NATURE PROCEDURE BILATERAL IN NATUREDetails →
1089SERVICE DENIED SERVICE DENIED BECAUSE THE RELATED OR QUALIFYING SERVICE WAS NOT PAID …Details →
1090THIS SERVICE IS BUNDLED THIS SERVICE IS BUNDLED INTO SERVICES NOT OTHERWISE SPECIFIEDDetails →

Understanding Medical Claim Denial Codes

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.