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 | |
|---|---|---|---|---|---|
| X456 | FQHC MUST BILL WITH ENCOUNTER CODE T1015 |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| X457 | Type of Bill 13x is invalid for Critical Access Hospital outpatient services. Please rebill using … |
MA30
Missing/incomplete/invalid type of bill. |
CO | 282 | View → |
| X46 | DIAGNOSIS AND AGE CONFLICT |
N517
Resubmit a new claim with the requested information. |
CO | 9 | View → |
| X468 | NDC billed is not in the proper format. The NDC must be in the 5-4-2 configuration. (line level de… |
M119
Missing/incomplete/invalid/ deactivated/withdrawn Nati… |
CO | 16 | View → |
| X469 | NDC billed is not in the proper format. The NDC must be in the 5-4-2 configuration. (claim level d… |
M119
Missing/incomplete/invalid/ deactivated/withdrawn Nati… |
CO | 16 | View → |
| X47 | DIAGNOSIS AND SEX CONFLICT |
N517
Resubmit a new claim with the requested information. |
CO | 10 | View → |
| X471 | Procedure code requires that an NDC must be billed according to NDC billing guidelines. (claim leve… |
N657
This should be billed with the appropriate code for th… |
CO | 16 | View → |
| X472 | S5190 is for reporting purposes only and is not payable. | — | CO | 246 | View → |
| X473 | RENDERING NPI IS NOT VALID FOR THIS ENCOUNTER. |
N570
Missing/incomplete/invalid credentialing data. |
CO | 185 | View → |
| X474 | Place of service is illogical. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| X475 | Long Acting Reversible Contraception (LARC) must be billed separately from the encounter. |
N130
Consult plan benefit documents/guidelines for informat… |
CO | 96 | View → |
| X48 | MEDICARE SECONDARY PAYER ALERT |
MA64
Our records indicate that we should be the third payer… |
CO | 22 | View → |
| X49 | E-DIAGNOSIS CODE CAN NOT BE USED AS PRINCIPAL DIAGNOSIS |
MA63
Missing/incomplete/invalid principal diagnosis. |
CO | 16 | View → |
| X499 | INSTITUTIONAL CLAIM WAS REGROUPED BASED ON POLICY. FINAL APR-DRG WAS CHANGED. | — | CO | 45 | View → |
| X5 | THE PATIENT SEX IS INVALID |
MA39
Missing/incomplete/invalid gender. |
CO | 7 | View → |
| X50 | INVALID PROCEDURE CODE |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 16 | View → |
| X500 | DIAGNOSTIC/THERAPEUTIC IMAGING RADIOPHARMACEUTICAL / CONTRAST AGENT LINK IS NOT COVERED BY MEDICARE… |
N657
This should be billed with the appropriate code for th… |
CO | 16 | View → |
| X507 | DRUG QUANTITY DISPENSED OR QUANTITY BILLED INFORMATION IS MISSING OR INVALID. |
M123
Missing/incomplete/invalid name, strength, or dosage o… |
CO | 16 | View → |
| X508 | Drug unit qualifier (unit of measure) is missing or invalid |
M123
Missing/incomplete/invalid name, strength, or dosage o… |
CO | 16 | View → |
| X51 | PROCEDURE AND AGE CONFLICT (INACTIVE) |
N129
Not eligible due to the patient's age. |
CO | 6 | View → |
| X517 | Possible improper billing of Accute Kidney Injury claim (Eff. 1/1/2017) |
N657
This should be billed with the appropriate code for th… |
CO | 16 | View → |
| X518 | Revenue code is no longer valid for this service, please rebill with correct H code. |
M50
Missing/incomplete/invalid revenue code(s). |
CO | 16 | View → |
| X519 | Place of service is missing or not valid. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| X52 | THE PROCEDURE PREFORMED AND THE PATIENT SEX CONFLICT |
M51
Missing/incomplete/invalid procedure code(s). |
CO | 7 | View → |
| X520 | Procedure code must be billed with Place of Service 55. |
M77
Missing/incomplete/invalid/inappropriate place of serv… |
CO | 16 | View → |
| X521 | SERIES BILL REVENUE CODE REQUIRED |
M50
Missing/incomplete/invalid revenue code(s). |
CO | 16 | View → |
| X522 | PER MEDICAID GUIDELINES, THIS PROCEDURE QUALIFIES FOR A MULTIPLE ENDOSCOPY REDUCTION AND PAYMENT SH… | — | CO | 203 | View → |
| X53 | NON-COVERED UNDER ANY MEDICARE OUTPATIENT BENEFIT, FOR REASONS OTHER THAN STATUTORY EXCLUSION |
N174
This is not a covered service/procedure/ equipment/bed… |
CO | 96 | View → |
| X539 | Inpatient Principal Hospital Acquired Condition | — | CO | 233 | View → |
| X54 | SERVICE SUBMITTED FOR DENIAL (CONDITION CODE 21) |
M44
Missing/incomplete/invalid condition code. |
CO | 16 | View → |
| X540 | INPATIENT OTHER HOSPITAL ACQUIRED CONDITION | — | CO | 233 | View → |
| X546 | THIS LINE ITEM CONFLICTS WITH CCI EDIT POLICY. | — | CO | 16 | View → |
| X547 | DME CODE BILLED WITH INVALID MODIFIER. |
N572
This procedure is not payable unless appropriate non-p… |
CO | 4 | View → |
| X548 | PAYMENT FOR DISCONTINUED PROCEDURES IS BASED ON PERCENTAGE OF SERVICE COMPLETED. PLEASE SUBMIT MED… |
N204
Services under review for possible pre-existing condit… |
CO | 163 | View → |
| X549 | AB CODE IS PART OF AN AUTOMATED PANEL. REIMBURSEMENT IS A PERCENTAGE OF MPFS ALLOWABLE. |
N381
Alert: Consult our contractual agreement for restricti… |
CO | 144 | View → |
| X55 | SERVICE SUBMITTED FOR FI/MAC REVIEW (CONDITION CODE 20) |
M44
Missing/incomplete/invalid condition code. |
CO | 16 | View → |
| X550 | FX MODIFIER (FILM XRAY) HAS A 20% REDUCTION OF THE TC (AND THE TC OF THE GLOABEL FEE) EFFECTIVE 1/1… |
N546
Payment represents a previous reduction based on the E… |
CO | 45 | View → |
| X551 | THIS IS A DUPLICATE LINE ITEM |
N522
Duplicate of a claim processed, or to be processed, as… |
CO | 18 | View → |
| X552 | SUPPLIES FURNISHED BY COMPREHENSIVE OUTPATIENT REHABILITATION FACILITIES (CORFS) OR OUTPATIENT PHYS… |
M15
Separately billed services/tests have been bundled as … |
CO | 97 | View → |
| X553 | (CERCLAGE REMOVAL) WILL BE DENIED AS INCLUDED IN THE DELIVERY FEE, WHEN THE REMOVAL OF A CERCLAGE I… |
N55
Procedures for billing with group/referring/performing… |
CO | 16 | View → |
| X554 | PROCEDURE CODE REQUIRES ICD-10 Z00.6 ALSO BE BILLED ON THE CLAIM. |
M76
Missing/incomplete/invalid diagnosis or condition. |
CO | 16 | View → |
| X555 | DME CODE BILLED WITH MODIFIER WILL BE DENIED BECAUSE SAME EQUIPMENT HAS BEEN PURCHASED WITHIN PAST … |
N417
This service is allowed 1 time in a 5-year period. |
CO | 119 | View → |
| X556 | (STERILE SALINE) BILLED WITH ORORPHARYNGEAL SUCTION CATHETER WHEN A TRACHEAL SUCTION CATHETER HAS N… |
N381
Alert: Consult our contractual agreement for restricti… |
CO | 169 | View → |
| X557 | (MASTECTOMY BRA) WILL BE DENIED IF BREAST PROSTHESIS HAS NOT BEEN BILLED WITHIN THE PREVIOUS TWO (2… |
N381
Alert: Consult our contractual agreement for restricti… |
CO | 16 | View → |
| X558 | () IS DENIED BECAUSE THE SAME PROCEDURE HAS BEEN RENDERED TO THE MEMBER ON WITHIN THE PREVIOUS FIVE… |
N640
Exceeds number/frequency approved/allowed within time … |
CO | 151 | View → |
| X559 | (DME REPAIR) IS DENIED BECAUSE THE MEMBER HAS DURABLE MEDICAL EQUIPMENT PURCHASE ON THE SAME SERVIC… |
M86
Service denied because payment already made for same/s… |
CO | 16 | View → |
| X56 | QUESTIONABLE COVERED SERVICE |
N661
Documentation does not support that the services rende… |
OA | 50 | View → |
| X560 | (DME REPAIR) IS DENIED BECAUSE IT WAS BILLED WITH A FREQUENTLY SERVICED RENTAL ITEM APPENDED WITH M… |
MA114
Missing/incomplete/invalid information on where the se… |
CO | 16 | View → |
| X561 | (POWER WHEELCHAIR ACCESSORY) IS DENIED BECAUSE POWER WHEELCHAIR WAS NOT FOUND IN CLAIM HISTORY WITH… |
MA114
Missing/incomplete/invalid information on where the se… |
CO | 151 | View → |
| X562 | STATIONARY OXYGEN SYSTEM IS NOT COVERED BY CMS WHEN BILLED MORE THAN ONCE WITHIN THE SAME MONTH. |
N640
Exceeds number/frequency approved/allowed within time … |
CO | 151 | 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.