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 |
|---|---|---|
| 1091 | RENTAL CAP EXCEEDED RENTAL CAP EXCEEDED | Details → |
| 1092 | NCCI DENIAL FOR COMPREHENSIVE/COMPONENT PROCEDURE NATIONAL CORRECT CODING INITIATIVE … | Details → |
| 1093 | NCCI DENIAL FOR MUTUALLY EXCLUSIVE PROCEDURES NATIONAL CORRECT CODING INITIATIVE DENI… | Details → |
| 1094 | NATIONAL CORRECT CODING POLICY MANUAL GUIDELINE NATIONAL CORRECT CODING POLICY MANUAL… | Details → |
| 1095 | CLINICAL TRIAL REQUIRES APPROPRIATE DIAGNOSIS CLINICAL TRIAL REQUIRES APPROPRIATE DIA… | Details → |
| 1096 | COMPONENT OF CRITICAL CARE SERVICE COMPONENT OF CRITICAL CARE SERVICE | Details → |
| 1097 | CO-SURGEONS CANNOT BE SAME SUBSPECIALTY CO-SURGEONS CANNOT BE SAME SUBSPECIALTY | Details → |
| 1098 | REDUCTION FOR IONIC CONTRAST MEDIA REDUCTION FOR IONIC CONTRAST MEDIA | Details → |
| 1099 | EXCEEDS COVERAGE GUIDELINES EXCEEDS COVERAGE GUIDELINES | Details → |
| 1100 | INVALID AGE FOR SERVICE PROVIDED INVALID AGE FOR SERVICE PROVIDED | Details → |
| 1101 | CPT RECODED TO A CMS DESIGNATED ALTERNATE HCPCS C CPT RECODED TO A CMS DESIGNATED ALT… | Details → |
| 1102 | HCPCS RECODED BASED ON AGE HCPCS RECODED BASED ON AGE | Details → |
| 1103 | GENDER-SPECIFIC PROCEDURE PRIOVIDER ASSIGNED A GENDER-SPECIFIC PROCEDURE TO A PATIENT… | Details → |
| 1104 | HCPCS RECODED BASED ON GENDER HCPCS RECODED BASED ON GENDER | Details → |
| 1105 | INCLUDED IN GLOBAL FEE INCLUDED IN GLOBAL FEE | Details → |
| 1106 | CPT CODE NOT VALID FOR DOS CPT CODE NOT VALID FOR THIS DATE OF SERVICE. PLEASE RESUBM… | Details → |
| 1107 | CONVENIENCE ITEM - DOES NOT MEET DEFINITION OF DM CONVENIENCE ITEM - DOES NOT MEET DE… | Details → |
| 1108 | SERVICE CAN ONLY BE BILLED TO DMERC SERVICE CAN ONLY BE BILLED TO DMERC | Details → |
| 1109 | DUPLICATE SERVICE WITHIN 30 DAYS DUPLICATE SERVICE WITHIN 30 DAYS | Details → |
| 1110 | DUPLICATE SERVICE ON SAME DAY DUPLICATE SERVICE ON SAME DAY | Details → |
| 1111 | DIAGNOSIS INAPPROPRIATE FOR AGE DIAGNOSIS INAPPROPRIATE FOR AGE | Details → |
| 1112 | DIAGNOSIS INAPPROPRIATE FOR GENDER DIAGNOSIS INAPPROPRIATE FOR GENDER | Details → |
| 1113 | PRINCIPAL DIAGNOSIS INAPPROPRIATELY CODED PRINCIPAL DIAGNOSIS INAPPROPRIATELY CODED | Details → |
| 1114 | E & M LEVEL OF SERVICE RECODED E & MLEVEL OF SERVICE RECODED | Details → |
| 1115 | E/M SERVICE INAPPROPRIATELY CODED E/M SERVICE INAPPROPRIATELY CODED | Details → |
| 1116 | EXCEEDS CLINICAL GUIDELINES THIS MANY SERVICES, THIS LENGTH OF SERVICE, THIS DOSAGE O… | Details → |
| 1117 | EXPERIMENTAL/INVESTIGATIONAL PROCEDURE/TREATMENT IS DEEMED EXPERIMENTAL/INVESTIGATION… | Details → |
| 1118 | THIS DATE OF SERVICE IS AFTER THE PATIENT'S DEATH THIS DATE OF SERVICE IS AFTER THE P… | Details → |
| 1119 | RESUBMIT WITH APPROPRIATE MEDICARE G CODE RESUBMIT WITH APPROPRIATE MEDICARE G CODE | Details → |
| 1120 | ADJUSTMENT ADJUSTMENT FOR COMPONENT OF PROFESSIONAL, TECHNICAL OR GLOBAL SERVICES | Details → |
| 1121 | PARTIAL HOSPITALIZATION REQUIRES MENTAL HEALTH DI PARTIAL HOSPITALIZATION REQUIRES ME… | Details → |
| 1122 | INCLUDED IN PHYSICAL MEDICINE SERVICE INCLUDED IN PHYSICAL MEDICINE SERVICE | Details → |
| 1123 | INCLUDE IN MONTHLY RENTAL FEE INCLUDE IN MONTHLY RENTAL FEE | Details → |
| 1124 | INCLUDED IN OTHER CODE INCLUDED IN OTHER CODE | Details → |
| 1125 | PROCEDURE CODE IS AN "INCIDENT TO" SERVICE PROCEDURE CODE IS AN "INCIDENT TO" SERVICE | Details → |
| 1126 | REIMBURSEMENT FOR SERVICE IS INCLUDED REIMBURSEMENT FOR SERVICE IS INCLUDED IN THE PA… | Details → |
| 1127 | PLEASE CODE ICD9 TO HIGHEST LEVEL PLEASE CODE ICD9 TO HIGHEST LEVEL OF SPECIFICITY US… | Details → |
| 1128 | MODIFIER INAPPROPRIATE FOR PROCEDURE MODIFIER INAPPROPRIATE FOR PROCEDURE | Details → |
| 1129 | SERVICE PART OF AN INPATIENT ONLY PROCEDURE SERVICE PART OF AN INPATIENT ONLY PROCEDU… | Details → |
| 1130 | INVALID REVENUE CODE INVALID REVENUE CODE | Details → |
| 1131 | SEPARATE PROCEDURES NOT SEPARATELY PAYABLE SEPARATE PROCEDURES NOT SEPARATELY PAYABLE | Details → |
| 1132 | IMPLANT PROCEDURE REQUIRES IMPLANT DEVICE IMPLANT PROCEDURE REQUIRES IMPLANT DEVICE | Details → |
| 1133 | EXCEED LAB PANEL PRICE PRICE OF LAB PANEL COMPONENTS EXCEED LAB PANEL PRICE | Details → |
| 1134 | RECODED TO THE LEAST COSTLY ALTERNATIVE RECODED TO THE LEAST COSTLY ALTERNATIVE | Details → |
| 1135 | MODIFIER REMOVED MODIFIER REMOVED, TERMINATED PROCEDURE CANNOT BE BILLED BILATERALLY | Details → |
| 1136 | SITE OF SERVICE DIFFERENTIAL SITE OF SERVICE DIFFERENTIAL | Details → |
| 1137 | MULTIPLE ENDOSCOPY REVIEW MULTIPLE ENDOSCOPY REVIEW | Details → |
| 1138 | OUTPATIENT MENTAL HEALTH TREATMENT OUTPATIENT MENTAL HEALTH TREATMENT LIMITATION APPL… | Details → |
| 1139 | MODIFIER INAPPROPRIATELY CODED MODIFIER INAPPROPRIATELY CODED | Details → |
| 1140 | CPT MODIFIER IS NOT VALID CPT MODIFIER IS NOT VALID | Details → |
| 1141 | MODIFIER CA ONLY ALLOWED ONCE PER DOS MODIFIER CA ONLY ALLOWED ONCE PER DATE OF SERVI… | Details → |
| 1142 | MODIFIER DENOTES FULL OR PARTIAL DEVICE CREDIT MODIFIER DENOTES FULL OR PARTIAL DEVIC… | Details → |
| 1143 | MODIFIERS RE-ORDERED MODIFIERS RE-ORDERED | Details → |
| 1144 | SERVICE CODE IS INCONSISTENT THE SERVICE CODE IS INCONSISTENT WITH THE MODIFIER USED … | Details → |
| 1145 | MODIFIER INAPPROPRIATE FOR PROVIDER TYPE MODIFIER INAPPROPRIATE FOR PROVIDER TYPE | Details → |
| 1146 | MODIFIER INAPPROPRIATE FOR PLACE OF SERVICE MODIFIER INAPPROPRIATE FOR PLACE OF SERVI… | Details → |
| 1147 | MODIFIER ADJUSTMENT MODIFIER ADJUSTMENT | Details → |
| 1148 | ONLY ONE ANESTHESIA SERVICE PER OPERATIVE SESSION ONLY ONE ANESTHESIA SERVICE PER OPE… | Details → |
| 1149 | MULTIPLE NUCLEAR MEDICINE STUDIES MULTIPLE NUCLEAR MEDICINE STUDIES | Details → |
| 1150 | MULTIPLE PROCEDURE REVIEW MULTIPLE PROCEDURE REVIEW | 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.