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
1151HCPCS CODE NOT APPROPRIATE FOR PROFESSIONAL BILLI HCPCS CODE NOT APPROPRIATE FOR PROF…Details →
1152NOT COVERED FOR DIAGNOSIS INDICATED NOT COVERED FOR DIAGNOSIS INDICATEDDetails →
1153PLACE OF SERVICE INAPPROPRIATE FOR PROCEDURE PLACE OF SERVICE INAPPROPRIATE FOR PROCE…Details →
1154NEW PATIENT VISIT ALLOWED ONCE PER 3 YEARS NEW PATIENT VISIT ALLOWED ONCE PER 3 YEARSDetails →
1155MULTIPLE PHYSICIANS/ASSISTANTS MULTIPLE PHYSICIANS/ASSISTANTS ARE NOT COVERED IN THIS…Details →
1156CO-SURGEONS NOT ALLOWED FOR THIS PROCEDURE. CO-SURGEONS NOT ALLOWED FOR THIS PROCEDUR…Details →
1157NOT COVERED BY PROV IN POS NOT COVERED WHEN PERFORMED BY THIS PROVIDER IN THIS PLACE …Details →
1158NOT SEPARATELY REIMBURSABLE UNDER OPPS THE SERVICES REPORTED ON THIS CLAIM ARE NOT SE…Details →
1159NOT CONSIDERED SAFE AND/OR EFFECTIVE. NOT CONSIDERED SAFE AND/OR EFFECTIVE.Details →
1160PROCEDURE RECODED TO DELIVERY ONLY SERVICES PROCEDURE RECODED TO DELIVERY ONLY SERVIC…Details →
1161DOES NOT MEET CRITERIA FOR OBSERVATION SERVICES DOES NOT MEET CRITERIA FOR OBSERVATIO…Details →
1162PAYABLE ONLY WITH ACTIVE INTERVENTION PAYABLE ONLY WITH ACTIVE INTERVENTIONDetails →
1163PART OF ANOTHER PROCEDURE THIS SERVICE IS CONSIDERED PART OF ANOTHER PROCEDURE PERFOR…Details →
1164CODE BILLED IS NOT CORRECT/VALID PROCEDURE CODE BILLED IS NOT CORRECT/VALID FOR THE S…Details →
1165PROFESSIONAL COMPONENT NOT PAYABLE PROFESSIONAL COMPONENT NOT PAYABLE FOR THIS PLACE …Details →
1166MISSING/INCOMPLETE/INVALID PRINCIPAL DIAGNOSIS CO MISSING/INCOMPLETE/INVALID PRINCIPA…Details →
1167PARTIAL HOSPITALIZATION NOT INDICATED PARTIAL HOSPITALIZATION NOT INDICATEDDetails →
1168PROCEDURE INAPPROPRIATELY CODED PROCEDURE INAPPROPRIATELY CODEDDetails →
1169PROCEDURE INCLUDED WITH E/M SERVICE PROCEDURE INCLUDED WITH E/M SERVICEDetails →
1170PROCEDURE INVALID FOR MEDICARE PURPOSES PROCEDURE INVALID FOR MEDICARE PURPOSESDetails →
1171PACKAGED INCIDENTAL SERVICE PACKAGED INCIDENTAL SERVICEDetails →
1172CONDITION CODE NOT APPROPRIATE FOR BILL TYPE CONDITION CODE NOT APPROPRIATE FOR BILL …Details →
1173DUPLICATE SUBMISSION DUPLICATE SUBMISSIONDetails →
1174DUPLICATE OF A NEW OR DELETED PROCEDURE CODE DUPLICATE OF A NEW OR DELETED PROCEDURE …Details →
1175QUESTIONABLE SERVICE QUESTIONABLE SERVICEDetails →
1176INVALID ICD9 DIAGNOSIS CODE ON CLAIM. CORRECT AND INVALID ICD9 DIAGNOSIS CODE ON CLAI…Details →
1177MULTIPLE PROCEDURE REDUCTION FOR RADIOLOGY MULTIPLE PROCEDURE REDUCTION FOR RADIOLOGYDetails →
1178INCLUDED IN RADIATION TREATMENT MANAGEMENT SERVIC INCLUDED IN RADIATION TREATMENT MAN…Details →
1179REVENUE CODE AND HCPCS DO NOT MATCH REVENUE CODE AND HCPCS DO NOT MATCHDetails →
1180HCPCS RECODED PER HEALTH PLAN POLICY HCPCS RECODED PER HEALTH PLAN POLICYDetails →
1181RECODED RECODED TO A CODE THAT MORE ACCURATELY DESCRIBES THE SERVICES RENDEREDDetails →
1182RETURN TO OR PAYMENT ADJUSTMENT RETURN TO OR PAYMENT ADJUSTMENTDetails →
1183INCLUDED IN BLOOD/BLOOD PRODUCT REVENUE CODE INCLUDED IN BLOOD/BLOOD PRODUCT REVENUE …Details →
1184REVENUE CODE DOES NOT MATCH BILL TYPE REVENUE CODE DOES NOT MATCH BILL TYPEDetails →
1185REVENUE CODE INAPPROPRIATELY CODED REVENUE CODE INAPPROPRIATELY CODEDDetails →
1186REVENUE CODE REQUIRES HCPCS CODE REVENUE CODE REQUIRES HCPCS CODEDetails →
1187REVENUE CODE NOT RECOGNIZED BY MEDICARE REVENUE CODE NOT RECOGNIZED BY MEDICAREDetails →
1188SERVICE DENIED SERVICE DENIED BECAUSE OF POTENTIAL INTERACTION WITH ANOTHER DRUG ADMI…Details →
1189SEPARATE PAYMENT FOR SERVICES NOT PROVIDED BY MED SEPARATE PAYMENT FOR SERVICES NOT P…Details →
1190CPT SEPARATE PROCEDURE POLICY CPT SEPARATE PROCEDURE POLICYDetails →
1191PRE AND INTRA OPERATIVE CARE PAYMENT INCLUDES SERVICES FOR PRE AND INTRA OPERATIVE CA…Details →
1192SERVICE PREVIOUSLY PROCESSED SERVICE PREVIOUSLY PROCESSED AND PAID TO THE SAME OR DIF…Details →
1193SAME/SIMILAR SERVICE PERFORMED RECENTLY SAME/SIMILAR SERVICE PERFORMED RECENTLYDetails →
1194TECHNICAL SERVICES NOT PAYABLE FOR THIS PLACE OF TECHNICAL SERVICES NOT PAYABLE FOR T…Details →
1195TEAM SURGERY NOT ALLOWED TEAMSURGERY NOT ALLOWEDDetails →
1196TERMINATED PROCEDURE CANNOT BE BILLED BILATERALLY TERMINATED PROCEDURE CANNOT BE BILL…Details →
1197TECHNICAL/ PROFESSIONAL SERVICE INAPPROPRIATELY C TECHNICAL/ PROFESSIONAL SERVICE INA…Details →
1198Auth Modifier MisMatch Please resubmit the claim. The modifier(s) billed on the claim…Details →
1199No PCP assignment CALL 1-800-291-0396 TO SELECT A PCPDetails →
1200Referral Required Benefit requires an authorization or referralDetails →
1201Missing/Invalid TPI Please resubmit with a valid Texas Provider Identification (TPI) …Details →
1202Provider is not certified/eligible This provider was not certified/eligible to be pai…Details →
1203Included in composite rate Services are included in composite rateDetails →
1205Rendering NPI Please resubmit with a Valid Billing Provider NPIDetails →
1206Medicaid/ Copay and Deductible This member�s coverage through HealthSpring is for lon…Details →
1207Provider Mismatch Provider name in box 33 does not match the NPI and/ or Tax Id submi…Details →
1208Valid Rendering NPI Please resubmit with Valid Rendering Provider NPIDetails →
1209C Pend 1 The Requested EOB was not received within the allotted timeframe.Details →
1210C Pend 2 The Requested Operative Note was not received within the allotted timeframe.Details →
1211C Pend 3 The Requested Invoice was not received within the allotted timeframe.Details →

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.