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M128 Remark Code (Deactivated): Last Physician Visit Date

M128 meant the date of the patient's last physician visit was missing, incomplete, or invalid on the claim. X12 deactivated it without naming a successor; N324, which covers the last seen or visit date, is the closest active remark.

X12 deactivated RARCM128 on June 2, 2005. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: M128 (RARC M128)
Status: Deactivated StoppedJune 2, 2005 (in use since January 1, 1997).
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): Paired with CO missing-information adjustments; adding the date was the provider's responsibility.
Official description: Missing/incomplete/invalid date of the patient's last physician visit.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What M128 meant

Remark M128 gave the specific reason behind a missing-information denial: the date the patient last saw a physician was absent or unusable. It was the remark-code counterpart to the deactivated adjustment code D7, and it applied to services where coverage depends on recent physician involvement.

What replaced it

X12 did not name a replacement, but N324 is active and covers a missing, incomplete, or invalid last seen or visit date. It usually accompanies CO-16. The older adjustment code for the same situation is explained on the CO-D7 page.

If you still see M128

It only exists in older remittances. For a current denial, find the qualifying physician visit in the record, make sure it falls within the payer’s window, report the date in the claim’s last seen date field along with the physician’s NPI if required, and resubmit.

N324 (Missing/incomplete/invalid last seen/visit date.): Missing, incomplete, or invalid last seen or visit date.
CO-16 (Claim/service lacks information or has submission/billing error(s).): Claim lacks information or has billing errors.
CO-D7Deactivated (Claim/service denied.): The deactivated adjustment code that described the same missing date.

M128 FAQ

Why did a claim need the last physician visit date?

Some services, such as routine foot care for qualifying patients, are covered only if a physician has seen the patient within a set period. The date lets the payer check that.

What if the last visit was too long ago?

Then the requirement is not met for that service date. The patient may need a new physician visit before future services qualify.

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