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MA104 Remark Code (Deactivated): Last Seen or Attending ID

MA104 meant either the date the patient was last seen or the attending physician's provider identifier was missing, incomplete, or invalid. X12 deactivated it and suggested M128 or M57, both since retired; N324 and N253 are the active equivalents.

X12 deactivated RARCMA104 on January 31, 2004. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: MA104 (RARC MA104)
Status: Deactivated StoppedJanuary 31, 2004 (in use since January 1, 1997).
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): Accompanied CO missing-information adjustments; the provider needed to add the date or identifier.
Official description: Missing/incomplete/invalid date the patient was last seen or the provider identifier of the attending physician.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What MA104 meant

Remark MA104 combined two pieces of information that often travel together: when the patient was last seen by a physician, and who that physician was. If either was missing or invalid, the claim was returned with this remark.

What replaced it

X12’s note suggested M128 for the date or M57 for the identifier. Both M128 and M57 were later deactivated. The active remarks that carry these meanings now are N324 for the last seen or visit date and N253 for the attending provider identifier.

If you still see MA104

It only exists in older remittances. For a current rejection, find the qualifying physician visit and that physician’s NPI in the record, enter both in the fields the payer specifies, and resubmit.

M128Deactivated (Missing/incomplete/invalid date of the patient's last physician visit.): Suggested replacement for the date half, later deactivated.
M57Deactivated (Missing/incomplete/invalid provider identifier.): Suggested replacement for the identifier half, later deactivated.
N324 (Missing/incomplete/invalid last seen/visit date.): Missing, incomplete, or invalid last seen or visit date.
N253 (Missing/incomplete/invalid attending provider primary identifier.): Missing, incomplete, or invalid attending provider primary identifier.

MA104 FAQ

Why were these two items combined?

For certain services, such as routine foot care, the payer wanted both the date the patient was last seen by a physician and that physician's identifier to confirm ongoing physician care.

Which active remark should I look for today?

N324 for the last seen date, and a provider-role remark such as N253 or N290 for the identifier, depending on how the payer maps the physician.

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