MassHealth will provide the 835 Electronic Remittance Advice transaction as a download via the Provider Online Service Center (POSC) to any provider who has signed a MassHealth Trading Partner Agreement (TPA). Testing for this transaction is not required. Format requirements and applicable standard codes are listed in the Implementation Guide, which can be downloaded from the HIPAA section of Washington Publishing Company (WPC) Web site at


Claim Adjustment Reason Codes (CARC) explain why a claim or service line was adjudicated differently than it was billed. The only time a claim will not have an adjustment reason code is when the payment amount is equal to the billed amount.

Remittance Advice Remark Codes (RARC) are used within the 835 Health Care Remittance Advice and Payment Transaction in conjunction with the Claim Adjustment Reason Codes to convey information, and to provide clarification or a supplemental explanation for an adjustment already described by a Claim Adjustment Reason Code.

To facilitate the reconciliation of denied claims, the following crosswalk matches the MassHealth explanation of benefits (EOB) codes to a corresponding Healthcare Claim Adjustment Reason Code, and when appropriate, a Remittance Advice Remark Code that appears on 835 transactions. Note: You should only reference this crosswalk when reconciling denied claims.

Claim Adjustment Reason Codes and Remittance Advice Remark Codes (CARCs and RARCs)  pdf format of CARCs and RARCs Codes
doc format of                             CARCs and RARCs Codes                file size 2MB

The Council for Affordable Quality Healthcare (CAQH) reviews the CARC and RARC codes quarterly and makes updates as needed. Please check this site periodically for the most current version of the crosswalk.

If you have any questions about this information or would like to begin receiving the 835 transaction contact MassHealth Customer Service by e-mail at: or call 1-800-841-2900.

This information is provided by MassHealth.