MA39 remark code

Remittance advice remark code MA39. Remark codes add detail to the reason code on the same claim line.

Missing or invalid patient sex

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What MA39 means

The patient's sex on the claim is missing, not valid, or conflicts with the payer's records.

The payer could not use the sex field on the claim. It may have been blank, coded wrong, or did not match the member file, which can also trigger edits on services tied to a specific sex.

It usually comes with reason code 16. Some payers have special handling when a service and the recorded sex do not align, so check their policy.

Common causes

• The sex field was left blank or used an unaccepted value.
• The patient record and the payer's enrollment file disagree.
• A service was flagged because the payer's edit expected a different value.

What to do next

1. Check the value in the patient record against the payer's eligibility response.
2. Correct the field and resubmit the claim.
3. If the service is right for the patient, check the payer's policy for how to show that on the claim.

Related codes

• 16 (reason code) Missing information or billing error
• MA36 (remark code) Missing or invalid patient name