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 | |
|---|---|---|---|---|---|
| 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 → |
| IMD1 | PROCEDURE REQUIRES A REVIEW OF THE MEDICAL NECESSITY OF A SURGICAL ASSISTANT. | — | CO | 54 | View → |
| IMD2 | PROCEDURE REQUIRES A REVIEW OF THE MEDICAL NECESSITY OF TWO SURGEONS. | — | CO | 54 | View → |
| IMD3 | PROCEDURE REQUIRES A REVIEW OF THE MEDICAL NECESSITY OF A SURGICAL TEAM. | — | CO | 54 | View → |
| IMDC | MANIFESTION CODES ARE NOT ALLOWED AS THE ADMISSION DIAGNOSIS. |
MA65
Missing/incomplete/invalid admitting diagnosis. |
CO | 16 | View → |
| IMDH | This procedure code and a procedure code in patient's history indicate that multiple imaging servic… | — | CO | 134 | View → |
| IMDT | Per the Medicare Physician Fee Schedule, the submitted Procedure Code describes a diagnostic proced… |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| IMEO | PROCEDURE IS MUTALLY EXCLUSIVE TO ANOTHER PROCEDURE EITHER ON THIS CLAIM OR A CLAIM IN HISTORY. | — | CO | 231 | View → |
| IMFD | MAXIMUM DAILY FREQUENCY FOR PROCEDURE EXCEEDED. |
N435
Exceeds number/frequency approved /allowed within time… |
CO | 96 | View → |
| IMFH | The maximum frequency for this procedure has been exceeded between this claim and the same procedur… |
N640
Exceeds number/frequency approved/allowed within time … |
CO | 222 | View → |
| IMFP | Charges are within the Global Follow up days of the procedure performed. |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IMFX | MAXIMUM FREQUENCY FOR PROCEDURE EXCEEDED. |
N435
Exceeds number/frequency approved /allowed within time… |
CO | 119 | View → |
| IMGT | Per the Medicare Physician Fee Schedule the procedure code describes the global code of a service o… |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| IMIC | MODIFIER YZ IS NOT APPROPRIATE FOR THIS SERVCE |
N517
Resubmit a new claim with the requested information. |
CO | 4 | View → |
| IMMV | MULTIPLE VISITS CANNOT BE BILLED ON THE SAME DAY FOR THE SAME REVENUE CODE | — | CO | 59 | View → |
| IMP | 50% REDUCTION OF ALLOWED AMOUNT APPLIED TO LINE. | — | CO | 59 | View → |
| IMP5 | OPERATIVE REPORT REQUIRED WHEN MORE THAN 5 PROCEDURES ARE PERFORMED ON SAME DATE OF SERVICE |
M29
Missing operative note/report. |
CO | 252 | View → |
| IMPC | MODIFIER XY IS NOT APPROPRIATE FOR THIS SERVICE. |
N517
Resubmit a new claim with the requested information. |
CO | 4 | View → |
| IMPI | PHYSICIAN INTERPRETATION SERVICE NOT PAYABLE IN PLACE OF SERVICE BILLED. | — | CO | 58 | View → |
| IMPT | PHYSICAL THERAPY SERVICE NOT PAYABLE IN PLACE OF SERVICE BILLED. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 5 | View → |
| IMTC | MODIFIER BILLED IS INAPPROPRIATE AS THE PROCEDURE BILLED IS ONLY THE TECHNICAL PORTION OF THIS SERV… |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| IMTS | TEAM SURGERY IS NOT PERMITTED FOR THIS PROCEDURE. | — | CO | 54 | View → |
| INCD | PROCEDURE IDENTIFIED AS INCIDENTAL TO ANOTHER PROCEDURE. PATIENT IS NOT RESPONSIBLE FOR BALANCE. |
N19
Procedure code incidental to primary procedure. |
CO | 97 | View → |
| INCE | Non-covered based on statutory exclusion. |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| INCS | NOT A COVERED SERVICE UNDER THE PLAN BENEFITS. |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| INDR | INFORMATIONAL CODE ONLY. PATIENT IS NOT RESPONSIBLE FOR SERVICE | — | CO | B1 | View → |
| INFA | ASC billing needs to be billed by facility not individual provider |
M25
The information furnished does not substantiate the ne… |
CO | 16 | View → |
| INFD | CLAIM MUST BE BILLED WITH INFUSION DRUG OR APPROPRIATE REV CODE |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| INFO | THIS IS A NON-REIMBURSABLE INFORMATIONAL CODE ONLY |
M25
The information furnished does not substantiate the ne… |
CO | 16 | 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.