MA01 remark code

Remittance advice remark code MA01. Remark codes add detail to the reason code on the same claim line.

Alert: how to appeal this decision

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 MA01 means

An informational alert explaining that you can ask for a review if you disagree with the decision, and how to do it.

This remark tells you that you have appeal rights for the claim and gives general instructions for requesting a review. It is an alert and does not by itself explain why anything was reduced or denied.

The reason code on the line, not this alert, tells you how the payment changed. The deadline to appeal starts from the remittance date, so check the payer's time limit.

Common causes

• The claim had a denial or reduction that can be appealed.
• The payer includes this notice on many processed claims as standard information.
• The decision was made on the merits rather than returned as unprocessable.

What to do next

1. Read the reason code to see what decision you would be appealing.
2. Note the appeal deadline from the remittance date in your follow up system.
3. Gather records and a short explanation before filing the appeal.

Related codes

• MA130 (remark code) Unprocessable claim: correct and resubmit
• MA44 (remark code) No appeal rights: decision based on law
• M25 (remark code) Documentation does not support the level