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N939 Remark Code: Peer-to-Peer Review Available

N939 is an alert that you may contact the payer for a peer-to-peer review. The treating clinician can discuss the decision directly with the payer's physician or clinical reviewer, often before or instead of a formal written appeal.

Code: N939 (RARC N939)
Status: Active In use since July 1, 2026.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): The denied or reduced amount that a peer-to-peer discussion may change. It is not billed to the patient while under review.
Official description: Alert: You may contact us for a peer-to-peer review.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N939 means

A peer-to-peer review is a conversation between clinicians. Instead of exchanging documents, the treating provider explains the case to the payer’s reviewer, who can reconsider the decision. N939 tells you that option is open for this claim.

What to do

Find the payer’s request process and deadline, usually through provider services or the portal.
Brief the clinician on the denial reason and the payer’s policy criteria.
Have the record ready, including notes, test results, and prior treatments tried.
Document the outcome. If the decision is not changed, file a written appeal within the payer’s time limit.

Codes that may appear with N939

CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): A medical necessity denial, the most common reason to request a peer-to-peer.
CO-197 (Precertification/authorization/notification/pre-treatment absent.): Authorization was absent; some payers offer peer-to-peer on authorization decisions.
CO-151 (Payment adjusted because the payer deems the information submitted does not support this many/frequency of services.): The payer believes the information does not support the frequency of services.

N10 (Adjustment based on the findings of a review organization/professional consult/manual adjudication/medical advisor/dental advisor/peer review.): The adjustment was based on a review organization, medical advisor, or peer review finding.
N210 (Alert: You may appeal this decision.): A general alert that the decision may be appealed.
N1 (Alert: You may appeal this decision in writing within the required time limits following receipt of this notice by following the instructions…): You may appeal in writing within the required time limits.

N939 FAQ

Who takes part in a peer-to-peer review?

Usually the treating physician or another qualified clinician from the practice, and a physician or clinical reviewer from the payer. Billing staff typically schedule it but do not lead it.

Is there a deadline?

Payers often set a short window to request peer-to-peer after a decision. Check the payer's rules as soon as the remittance arrives.

Does a peer-to-peer replace a formal appeal?

It can resolve the issue faster, but if it does not, you can usually still file a formal appeal within the normal deadline.

Important: read before using this information

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