RARCM51ReferenceCurrentVerified Aug 15, 2026RARC M51
AR Guide explanation
What it means
The procedure code is missing, incomplete or invalid.
AR Guide knowledge
Common denial category
AR Guide knowledge
Common usage
- Claims with a procedure-code error (often with CARC 16)
About this guidance: Note
AR Guide knowledge is general reference content written by our team — it is not payer-specific policy and never replaces the payer’s documentation or your contract. Always confirm specifics with the payer.
Reference
Commonly paired CARCs
CARCs this remark commonly accompanies on the ERA/EOB, per the AR Guide pairing data.
CARC16Claim/service lacks information or has submission/billing error(s). Usage: Do not use this code for claims attachment(s)/other documentation. At least one Remark Code must be provided (may be comprised of either the NCPDP Reject Reason Code, or Remittance Advice Remark Code that is not an ALERT.) Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
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