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 | |
|---|---|---|---|---|---|
| INFX | THE PLAN DOES NOT PROVIDE BENEFITS RELATED TO INFERTILITY. |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| INJ | INJECTIONS MUST BE BILLED WITH INJECTED DRUG CODE |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| INPD | DIAGNOSIS NOT TO BE LISTED AS THE PRIMARY. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| INPT | NEW PATIENT VISIT BILLED FOR AN ESTABLISHED PATIENT; REBILL CORRECT CODE. |
m51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| INR | INTERVENTIONAL SURGERY PROCEDURE CODE MUST BE BILLED |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| INRS | HCPCS CODE BILLED IS NOT PAYABLE FOR TYPE OF BILL |
MA30
Missing/incomplete/invalid type of bill. |
CO | 282 | View → |
| INT | INTEREST PAYMENT APPLIED TO CLAIM. INITIAL PAYMENT EXCEEDED 30 DAYS. | — | CO | 225 | View → |
| INV | PLEASE SUBMIT THE M.S.R.P. OR MANUFACTUROR'S INVOICE FOR THESE SERVICES. |
M25
The information furnished does not substantiate the ne… |
CO | 16 | View → |
| IOAP | OBSERVATION HCPCS CODE MISSING FROM CLAIM PER HFS GUIDELINES. |
M20
Missing/incomplete/invalid HCPCS. |
CO | 16 | View → |
| IOID | INVALID OTHER DIAGNOSES. |
M64
Missing/incomplete/invalid other diagnosis. |
CO | 16 | View → |
| IOIS | ONLY INCIDENTAL SERVICES WERE BILLED ON THIS CLAIM. THESE SERVICES ARE TO BE PAID AS PART OF ANOTHE… |
N122
Add-on code cannot be billed by itself. |
CO | 234 | View → |
| IOSR | PRIMARY SURGICAL PROCEDURE TYPICALLY PERFORMED IN AN OFFICE SETTING. |
N34
Incorrect claim form/format for this service. |
CO | 5 | View → |
| IPAT | PATIENT ID MISSING. |
N382
Missing/incomplete/invalid patient identifier. |
CO | 16 | View → |
| IPC | INVALID PROCEDURE CODE. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IPCD | CODE NOT WITHIN APPROVAL DATE. |
N175
Missing review organization approval. |
CO | 251 | View → |
| IPCM | MODIFIER -26 IS NOT APPROPRIATE FOR THIS PROCEDURE BECAUSE THE PROCEDURE IS DEFINED AS 100% PROFESS… |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| IPD | INVALID PRINCIPAL DIAGNOSIS. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IPDE | E CODES ARE NOT ALLOWED AS PRINCIPAL DIAGNOSIS. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IPDI | DIAGNOSTIC INTERVIEW WILL BE DENIED AS PART OF CONSULTATION WHEN BILLED WITHIN 30 OF THAT CONSULT B… |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| IPDM | MANIFESTATION CODES NOT ALLOWED AS PRINCIPAL DIAGNOSIS. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IPDQ | PRINCIPAL DIAGNOSIS IS FOR QUESTIONABLE ADMISSION. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IPDS | PRINCIPAL DIAGNOSIS REQUIRES SECONDARY DIAGNOSIS. |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| IPDU | INVALID PROCEDURE CODE. INCLUDES UNNECESSARY ADDITIONAL DIGIT. |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| IPOS | INVALID PLACE OF SERVICE SUBMITTED. SERVICES MUST BE SUBMITTED WITH A VALID TWO DIGIT CODE. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 58 | View → |
| IPRD | REDUCTION FOR ASSISTANT, CO-, OR TEAM SURGEON. | — | CO | 59 | View → |
| IPRE | PRE-OP EXAM ONE DAY PRIOR TO PROCEDURE IS PART OF THE GLOBAL SURGICAL PACKAGE AND NOT ALLOWED. |
N525
These services are not covered when performed within t… |
CO | 96 | View → |
| IPRV | MISSING PROVIDER ID. | — | CO | 206 | View → |
| IPSC | PATIENT STATUS CODE MISSING OR INVALID |
MA43
Missing/incomplete/invalid patient status. |
CO | 16 | View → |
| IPSX | PATIENT GENDER MISSING OR INVALID |
MA39
Missing/incomplete/invalid gender. |
CO | 16 | View → |
| IRRH | REVENUE CODE ALSO REQUIRES HCPCS CODE. |
M20
Missing/incomplete/invalid HCPCS. |
CO | 16 | View → |
| ISAM | ONLY ONE SURGICAL ASSISTANT IS ALLOWED FOR THIS PROCEDURE. | — | CO | 54 | View → |
| ISAS | PROCEDURE TYPICALLY DOES NOT REQUIRE A SURGICAL ASSISTANT. | — | CO | 54 | View → |
| ISBP | MEDICAID BILATERAL PAYMENT ADJUSTMENT |
N644
Reimbursement has been made according to the bilateral… |
CO | 59 | View → |
| ISDR | MEDICAID DIAGNOSTIC RADIOLOGY REDUCTION | — | CO | 59 | View → |
| ISER | MEDICAID MULTIPLE ENDOSCOPY REDUCTION | — | CO | 59 | View → |
| ISEX | The patient's gender is invalid or missing. |
MA39
Missing/incomplete/invalid gender. |
CO | 16 | View → |
| ISL | THE PROVIDER ADDRESS BILLED IS NOT A VALID SERVICE LOCATION. PLEASE RESUBMIT WITH ACTUAL SERVICE A… |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| ISMP | MEDICAID MULTIPLE PROCEDURE REDUCTION | — | CO | 59 | View → |
| ISMU | Per Medicaid Medically Unlikely Edits, the units of service billed for this procedure exceed the a… |
N640
Exceeds number/frequency approved/allowed within time … |
CO | 96 | View → |
| ISNA | INPATIENT SEPARATE PROCEDURE NOT PAID. |
M2
Not paid separately when the patient is an inpatient. |
CO | 96 | View → |
| ISOA | MISSING/INVALID POINT OF ORIGIN |
M25
The information furnished does not substantiate the ne… |
CO | 16 | View → |
| ISOP | The HCPCS code on this line is billed for a date of service that is not within the specified approv… |
N56
Procedure code billed is not correct/valid for the ser… |
CO | 181 | View → |
| ISPA | HCPCS DATE OF SERVICE NOT WITHIN FDA APPROVAL DATE. | — | CO | 188 | View → |
| ISSP | SERVICE IS NOT PAYABLE WHEN BILLED SEPARATELY |
N390
This service/report cannot be billed separately. |
CO | 97 | View → |
| ISTR | SURGICAL TRAY NOT BILLABLE FOR THIS PROCEDURE AND THIS PLACE OF SERVICE. |
N34
Incorrect claim form/format for this service. |
CO | 5 | View → |
| ISUB | Add-on procedure code has been submitted without an appropriate primary procedure code. |
N122
Add-on code cannot be billed by itself. |
CO | 234 | View → |
| ISUN | Per Medicaid National Correct Coding Initiative edits, Procedure Code billed has an unbundled relat… |
M15
Separately billed services/tests have been bundled as … |
CO | 234 | View → |
| ITBP | TERMINATED PROCEDURE SHOULD NOT BE BILLED AS BILATERAL. |
N519
Invalid combination of HCPCS modifiers. |
CO | 4 | View → |
| ITFE | MEDICARE TIMELY FILING | — | CO | 29 | View → |
| ITOA | MISSING OR INVALID TYPE OF ADMISSION |
MA30
Missing/incomplete/invalid type of bill. |
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.