remittance advice remark codes (RARC)
A RARC provides additional explanation for an adjustment already described by a Claim Adjustment Reason Code (CARC) or conveys information about remittance processing. Each RARC identifies a specific message as shown in the Remittance Advice Remark Code List.
There are two types of RARCs: supplemental and informational. Most RARCs are supplemental. Supplemental RARCs provide additional explanation for an adjustment already described by a CARC. Informational RARCs are all prefaced with "Alert" and are often referred to as alerts. Alerts are used to convey information about remittance processing and are never related to a specific adjustment or a CARC.