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 | |
|---|---|---|---|---|---|
| IAD6 | Admit Diagnosis code invalid: Invalid code for date of admission, missing 4th/5th digit. |
MA65
Missing/incomplete/invalid admitting diagnosis. |
CO | 16 | View → |
| IADM | INVALID ADMIT DIAGNOSIS. MISSING NECESSARY ADDITIONAL DIGITS. |
MA65
Missing/incomplete/invalid admitting diagnosis. |
CO | 16 | View → |
| IADU | INVALID ADMIT DIAGNOSIS. INCLUDES UNNECESSARY DIGITS. |
MA65
Missing/incomplete/invalid admitting diagnosis. |
CO | 16 | View → |
| IAMB | A0425 DENIED IF BILLED WITHOUT A0428 OR A0429 | — | CO | B15 | View → |
| IANE | PROCEDURE BILLED BY A PROVIDER NOT LISTED AS ANESTHESIA PROVIDER. |
N95
This provider type/provider specialty may not bill thi… |
CO | 8 | View → |
| IANM | ANESTHESIA CODE REQUIRES APPROPRIATE MODIFIER | — | CO | 4 | View → |
| IAO | PROCEDURE IS AN ADD-ON CODE AND MUST BE BILLED WITH THE PRIMARY PROCEDURE. |
N122
Add-on code cannot be billed by itself. |
CO | 97 | View → |
| IASC | PRIMARY SURGICAL PROCEDURE TYPICALLY PERFORMED IN AN AMBULATORY SURGICAL CENTER. |
N34
Incorrect claim form/format for this service. |
CO | 5 | View → |
| IASD | More than one anesthesia procedure has been billed for the same date of service. Only the anesthesi… | — | CO | 59 | View → |
| IASH | ONLY HIGHER BASE UNIT VALUE ANESTHESIA CODE SHOULDE BE BILLED PER PROCEDURE. | — | CO | 59 | View → |
| IB | PLEASE SUBMIT ITEMIZED BILL |
N26
Missing itemized bill/statement. |
CO | 163 | View → |
| IBDS | SERVICE DATE IS MISSING, INVALID, OR NOT WITHIN THE DATE SPAN ON CLAIM. |
MA31
Missing/incomplete/invalid beginning and ending dates … |
CO | 16 | View → |
| IBFR | FREQUENCY DOES NOT MEET POLICY REQUIREMENTS FOR THIS PROCEDURE |
N435
Exceeds number/frequency approved /allowed within time… |
CO | 119 | View → |
| IBPR | Bilateral payment adjustment has been applied to the claim. |
N644
Reimbursement has been made according to the bilateral… |
CO | 59 | View → |
| IBPS | PLACE OF SERVICE MISSING OR INVALID. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 58 | View → |
| IBSP | Procedure Code is not typically performed by a physician at the billed Place of Service. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| ICA | CA MODIFIER REQUIRES PATIENT STATUS CODE 20. |
MA43
Missing/incomplete/invalid patient status. |
CO | 16 | View → |
| ICAG | PROCEDURE IS INCONSISTENT WITH THE PATIENT'S AGE. |
N517
Resubmit a new claim with the requested information. |
CO | 9 | View → |
| ICCA | The condition code on the claim is invalid. |
M44
Missing/incomplete/invalid condition code. |
CO | 16 | View → |
| ICCP | PROCEDURE IS A COMPONENT OF A COMPREHENSIVE PROCEDURE AND SHOULD BE DENIED. |
M15
Separately billed services/tests have been bundled as … |
CO | 234 | View → |
| ICDL | PROCEDURE CODE HAS BEEN DELETED. |
N517
Resubmit a new claim with the requested information. |
CO | 181 | View → |
| ICM | DIAGNOSIS MISSING, INVALID, OR TOO NON-SPECIFIC |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| ICON | CONDITION CODE MISSING/INVALID/OR REQUIRES REVIEW. |
M44
Missing/incomplete/invalid condition code. |
CO | 16 | View → |
| ICOS | Procedure is typically considered cosmetic. Please submit claim documentation. |
N130
Consult plan benefit documents/guidelines for informat… |
CO | 204 | View → |
| ICPD | THE CP CODE BILLED IS DUPLICATIVE OF THE E & M CODE BILLED IN THE PATIENT'S HISTORY. |
M86
Service denied because payment already made for same/s… |
CO | 97 | View → |
| ICPT | PROCEDURE CODE IS INVALID, MISSING OR DISABLED. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| ICSX | PROCEDURE INCONSISTENT WITH PATIENT'S GENDER. |
N517
Resubmit a new claim with the requested information. |
CO | 7 | View → |
| IDAC | Age conflict; patient's age and diagnosis code are inconsistent. |
N517
Resubmit a new claim with the requested information. |
CO | 9 | View → |
| IDAG | PATIENT'S AGE AND GENDER ARE INCONSISTENT WITH DIAGNOSIS. |
N517
Resubmit a new claim with the requested information. |
CO | 9 | View → |
| IDAS | Patient's gender and diagnosis code are inconsistent. | — | CO | 7 | View → |
| IDCM | ICD-9 TO ICD-10 DIAGNOSIS COMPARISON | — | CO | 20 | View → |
| IDD | DUPLICATE DIAGNOSIS ON SAME CLAM. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 16 | View → |
| IDDA | Patient's age and a diagnosis on this claim are incompatible. |
N517
Resubmit a new claim with the requested information. |
CO | 9 | View → |
| IDDB | Patient's gender and a diagnosis on this claim are incompatible. | — | CO | 7 | View → |
| IDDC | Patient's age and gender are incompatible with the patient's admission diagnosis. | — | CO | 7 | View → |
| IDDP | The Diagnosis code is a duplicate of the Principal Diagnosis. |
M76
Missing/incomplete/invalid diagnosis or condition. |
CO | 16 | View → |
| IDDS | The submitted Diagnosis code is a duplicate of another secondary diagnosis code on this claim. |
M76
Missing/incomplete/invalid diagnosis or condition. |
CO | 16 | View → |
| IDI2 | The diagnosis code is invalid; there is an unnecessary 4th/5th digit. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDI3 | The diagnosis code is invalid; there is a missing 4th/5th digit. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDI4 | The diagnosis code is invalid; the code was found on the ICD-9-CM table, but not valid for the pati… |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDI5 | The diagnosis code is invalid; there is an unnecessary 4th/5th digit for the patient's admission/di… |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDI6 | The diagnosis code is invalid; there is a missing 4th/5th digit for the patient's admission/dischar… |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDIA | Age invalid; not in range 0-124 years. |
N129
Not eligible due to the patient's age. |
CO | 6 | View → |
| IDID | The diagnosis code is invalid; the code is not found on the table of valid ICD-10-CM codes. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 146 | View → |
| IDIS | The Patient Gender is invalid. | — | CO | 7 | View → |
| IDOB | MISSING OR INVALID DATE OF BIRTH |
N329
Missing/incomplete/invalid patient birth date. |
CO | 16 | View → |
| IDP1 | The procedure code is invalid, the code is not found on the table of valid ICD-9-CM codes. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IDP2 | Principal Diagnosis Invalid - Manifestation code cannot be used as principal diagnosis. |
MA66
Missing/incomplete/invalid principal procedure code. |
CO | 16 | View → |
| IDP3 | Principal Diagnosis Invalid - Non-specific code cannot be used as principal diagnosis. |
MA66
Missing/incomplete/invalid principal procedure code. |
CO | 16 | View → |
| IDP4 | Principal Diagnosis Invalid - Principal diagnosis indicates questionable admission. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 146 | 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.