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MA38 Remark Code (Deactivated): Birth Date Missing

MA38 meant a birth date on the claim was missing, incomplete, or invalid. X12 deactivated it without naming a replacement; N329, for the patient's birth date, is the closest active remark.

X12 deactivated RARCMA38 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: MA38 (RARC MA38)
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; the provider had to fix the demographic data.
Official description: Missing/incomplete/invalid birth date.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What MA38 meant

Payers match claims to members partly by birth date. Remark MA38 said the birth date on the claim was blank, incomplete, or not a valid date, so the payer could not confirm the person’s identity or apply age-based rules.

What replaced it

No successor was named. The active remark N329 covers a missing, incomplete, or invalid patient birth date. When the birth date does not match the payer’s records, you may instead see CARC CO-31. If the birth date on the claim is after the date of service, payers use CO-14.

If you still see MA38

It is only in older files. For a current birth date rejection, pull the eligibility response, compare the patient and subscriber birth dates with your registration record, correct the error, and resubmit. Fixing the date in the patient’s demographic record prevents repeat rejections on later claims.

N329 (Missing/incomplete/invalid patient birth date.): Missing, incomplete, or invalid patient birth date.
CO-31 (Patient cannot be identified as our insured.): Patient cannot be identified as our insured, a common result of demographic mismatches.
CO-14 (The date of birth follows the date of service.): The date of birth follows the date of service.

MA38 FAQ

Could the birth date be the subscriber's rather than the patient's?

Yes. Claims can carry both. MA38 did not specify which. Check both the patient and subscriber dates against the insurance card or eligibility response.

How do birth date errors happen?

Typing mistakes at registration, swapped month and day, or using the subscriber's date for a dependent patient.

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