Browse all standardized Remark Codes (RARC) used on Medicare, Medicaid, and commercial payer remittance advice (835 ERA / EOB). Each code includes its RA835 mapping, adjustment group, reason code, and a dedicated resolution guide.
Browse Claim Adjustment Reason Codes — the codes that explain why a payment was reduced or denied.
| Remark Code | Description | RA835 Code | Group | Reason Code | |
|---|---|---|---|---|---|
| IDP5 | Principal Diagnosis Invalid - Unacceptable principal diagnosis |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 146 | View → |
| IDP6 | Principal Diagnosis Invalid - Unacceptable principal diagnosis without required secondary diagnosis. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 146 | View → |
| IDPC | MISSING PROCEDURE CODE FOR DEVICE BILLED. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IDPD | Principal Diagnosis Invalid - 'E' Code cannot be used as principal diagnosis |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 146 | View → |
| IDSC | Patient's age and gender are inconsistent with the patient's diagnosis code. | — | CO | 7 | View → |
| IDTU | DISCREPANCY BETWEEN UNITS AND FROM AND THROUGH DATES. |
N345
Date range not valid with units submitted. |
CO | 16 | View → |
| IDUP | CLAIM HAS BEEN IDENTIFIED AS A DUPLICATE CLAIM IN PATIENT'S HISTORY. |
M86
Service denied because payment already made for same/s… |
CO | 97 | View → |
| IDX | INVALID DX. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 16 | View → |
| IDXM | INVALID DIAGNOSIS. MISSING NECESSARY ADDITIONAL DIGITS. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 50 | View → |
| IDXU | INVALID DIAGNOSIS. INCLUDES UNNECESSARY ADDITIONAL DIGITS. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 50 | View → |
| IEMO | VISIT CANNOT BE BILLED SAME DAY AS PROCEDURE |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IEPD | E-CODES NOT ALLOWED AS PRINCIPAL DIAGNOSIS. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IERB | INVALID EMERGENCY ROOM BILLING REV/HCPC COMBINATION PER HFS APL GUIDELINES. |
N130
Consult plan benefit documents/guidelines for informat… |
CO | 272 | View → |
| IFMS | TRAINING AND EDUCATION MUST BE BILLED WITH OTHER SERVICES. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IFQH | INVALID POS CODE SUBMITTED FOR FQHC |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| IFTD | INVALID FROM AND/OR THROUGH DATES OR ADMISSION DATE. |
M25
The information furnished does not substantiate the ne… |
CO | 16 | View → |
| IGFP | Procedure Code is within the global period of History Procedure Code performed by the same provide… |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IGSP | PROCEDURE BILLED WITHIN GLOBAL PERIOD OF MAJOR PROCEDURE PERFORMED. |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IHAC | DIAGNOSIS INDICATES HOSPITAL ACQUIRED CONDITION WHICH IS NOT COVERED. | — | CO | 167 | View → |
| IHCC | The submitted procedure code is a component of a previously submitted code and should be denied. |
M15
Separately billed services/tests have been bundled as … |
CO | 97 | View → |
| IHME | The billed procedure code is considered Mutually Exclusive to a claim in the patient's history and … | — | CO | 231 | View → |
| IIAG | DIAGNOSIS INCONSISTENT WITH PATIENT AGE. |
M76
Missing/incomplete/invalid diagnosis or condition. |
CO | 9 | View → |
| IIBM | MODIFIER FB OR FC IS INVALID. |
N517
Resubmit a new claim with the requested information. |
CO | 4 | View → |
| IIBP | PROCEDURE IS BILATERAL AND SHOULD NOT BE BILLED MORE THAN ONCE PER DATE OF SERVICE. |
M15
Separately billed services/tests have been bundled as … |
CO | 97 | View → |
| IICD | The diagnosis billed is invalid or disabled. |
M76
Missing/incomplete/invalid diagnosis or condition. |
CO | 146 | View → |
| IICM | The Principal DX is missing or invalid. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 146 | View → |
| IICR | SURGICAL CODE REQUIRES CROSSWALK TO ANESTHESIA CODE. |
M25
The information furnished does not substantiate the ne… |
CO | 16 | View → |
| IIDX | Dx billed is a nonspecific diagnosis code and requires a fourth and/or fifth digit. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IIMC | MODIFIERS BILLED CANNOT BE USED ON SAME LINE. | — | CO | 4 | View → |
| IIMD | DIAGNOSIS AND MODIFIER COMBINATION INAPPROPRIATE. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 252 | View → |
| IIMO | INVALID MODIFIER. |
N517
Resubmit a new claim with the requested information. |
CO | 182 | View → |
| IINV | This Procedure Code is considered investigational or experimental. Please submit documentation. |
N623
Not covered when deemed unscientific/unproven/outmoded… |
CO | 55 | View → |
| IIPC | INVALID PROCEDURE CODE. |
M20
Missing/incomplete/invalid HCPCS. |
CO | 181 | View → |
| IIPP | Invalid inpatient principal procedure. |
MA66
Missing/incomplete/invalid principal procedure code. |
CO | 16 | View → |
| IIRC | MISSING OR INVALID REVENUE CODE. |
M50
Missing/incomplete/invalid revenue code(s). |
CO | 16 | View → |
| IISX | DIAGNOSIS INCONSISTENT WITH PATIENT GENDER. |
N517
Resubmit a new claim with the requested information. |
CO | 10 | View → |
| ILOS | PROCEDURE PERFORMED IS INCONSISTENT WITH THE LENGTH OF STAY. | — | CO | 152 | View → |
| ILPC | CLAIM LACKS REQUIRED PRIMARY CODE |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IM0 | THE CODE BILLED IS NOT ALLOWED PER INDIANA MEDICAID GUIDELINES. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 96 | View → |
| IM26 | Procedure Code billed requires a modifier -26 when billing for the professional component in this p… |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| IM54 | USE OF MODIFIER 54 INDICATES INTRAOPERATIVE PORTION OF THE GLOBAL ONLY. | — | CO | 236 | View → |
| IM55 | USE OF MODIFIER 55 INDICATES POSTOPERATIVE PORTION OF THE GLOBAL ONLY. | — | CO | 236 | View → |
| IM56 | USE OF MODIFIER 56 INDICATES PREOPERATIVE PORTION OF THE GLOBAL ONLY. | — | CO | 236 | View → |
| IM76 | REPEAT NONCLINICAL LAB PROCEDURES MUST BE BILLED WITH MODIFIER 76. |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IM78 | USE OF MODIFIER 78 INDICATES INTRAOPERATIVE PORTION OF THE GLOBAL ONLY. | — | CO | 236 | View → |
| IM91 | REPEAT DIAGNOSTIC TESTS MUST BE BILLED WITH MODIFIER 91 | — | CO | 4 | View → |
| IMAN | Anesthesia code on this line requires an appropriate modifier. | — | CO | 4 | View → |
| IMBP | BILATERAL PROCEDURE PAYMENT REDUCTION APPLIED. |
M15
Separately billed services/tests have been bundled as … |
CO | 97 | View → |
| IMCO | CO-SURGEONS ARE NOT PERMITTED FOR THIS PROCEDURE. | — | CO | 54 | View → |
| IMD | PROCEDURE REQUIRES REVIEW FOR MEDICAL NECESSITY OF ADDITIONAL PROVIDERS. | — | CO | 54 | View → |
Remark Codes (RARC) are used on the 835 ERA and paper EOB to provide supplemental information about a claim adjustment. They always accompany a CARC (denial code) and clarify the reason for payment differences.
A Denial Code (CARC) explains why payment was adjusted. A Remark Code (RARC) provides additional context or instructions. Both appear together on remittance — look for the CARC first, then the RARC for detail.
Search by code number or keyword, or filter by adjustment group (CO, PR, OA…). Click any code to see its full RA835 mapping, common causes, step-by-step resolution guide, and appeal tips.