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MA91 Remark Code: Determination Resulting From Your Appeal

MA91 is an informational alert. It tells you the determination on this remittance is the result of the appeal you filed, so the amounts shown reflect the appeal decision.

Code: MA91 (RARC MA91)
Status: Active In use since January 1, 1997; last modified July 1, 2015.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): Any remaining adjustment after the appeal is the provider's responsibility unless you pursue a further level of appeal.
PR (Patient Responsibility): After the appeal, the amount shown is assigned to the patient, for example as cost-sharing.
Official description: Alert: This determination is the result of the appeal you filed.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What MA91 means

MA91 is an alert that ties a remittance back to an appeal you filed. The payer has reconsidered the claim and the amounts on this line are the result. MA91 does not tell you whether you won; that comes from comparing the new payment and CARCs with the original decision.

What to do

Match the line to your appeal log using the claim number and appeal reference.
Compare the outcome with the original remittance to see what changed.
Post the result as an adjustment to the original claim.
Consider the next level if the decision was upheld and you still disagree, watching the deadline in the decision letter.
Record the result by denial reason. Appeal win rates by CARC show which denials are worth appealing; see CARC and RARC denial analysis.

Codes that may appear with MA91

CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): A medical necessity denial that was appealed and is now upheld or changed.
CO-197 (Precertification/authorization/notification/pre-treatment absent.): An authorization denial that was taken through the appeal process.

MA01 (Alert: If you do not agree with what we approved for these services, you may appeal our decision.): The appeal-rights alert that often appears on the original decision.
MA62 (Alert: This is a telephone review decision.): Identifies a telephone review decision instead of a formal appeal.
MA67 (Alert: Correction to a prior claim.): A general correction to a prior claim.

MA91 FAQ

Does MA91 mean I won the appeal?

Not by itself. Compare the payment and adjustments to the original remittance to see whether the decision changed.

What if I disagree with the appeal decision?

Check the decision notice for the next appeal level and its deadline. Medicare and many payers have multiple appeal levels.

How should I post an MA91 line?

Post it against the original claim and reconcile any additional payment or reversal, rather than treating it as a new claim.

Important: read before using this information

This page is general educational information about a standard industry code set. It is not medical billing, coding, legal, reimbursement, or compliance advice, and it does not create a professional or advisory relationship with ClaimsRevenue.

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