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N453 Remark Code: Missing Consultation Report

N453 means the consultation report is missing. The payer needs the written report from the consulting provider, the document that answers the requesting provider's question, and did not receive it.

Code: N453 (RARC N453)
Status: Active In use since July 1, 2008.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): The service is denied or held for documentation. The consulting provider supplies the report; the patient is not billed.
Official description: Missing Consultation Report.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N453 means

A consultation is a request from one provider for another provider’s opinion. The consultant evaluates the patient and sends back a written report. Payers that pay for consultations, or that need to understand what a specialist recommended, may require that report before paying. N453 says the payer did not receive it.

The remark usually accompanies CARC 252 or CARC 226.

When payers ask for a consultation report

Consultation services billed where the payer requires proof of the request and the report back.
Workers’ compensation cases where the carrier needs the specialist’s opinion on the injury, causation, or treatment plan.
Pre-service or post-service reviews of procedures recommended by the consultant.
Claims under medical review where the payer wants the full clinical picture.

Steps to resolve

Confirm what was requested and by when, from the payer’s letter or portal.
Locate the signed report and the documented request from the referring provider, since some payers want both.
Send the report through the payer’s attachment method with the claim number on it.
If the consultation code isn’t recognized by this payer, consider whether the visit should be billed with a different evaluation code instead, and correct the claim if appropriate.
Track the follow-up until the claim is reprocessed.

How to prevent it

Treat the consultation report as part of the service: the visit is not complete for billing until the report is signed and sent to the requesting provider. For payers that routinely require it, attach the report to the claim at submission.

Codes that may appear with N453

CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): Documentation is required; N453 specifies the consultation report.
CO-226 (Information requested from the Billing/Rendering Provider was not provided or not provided timely or was insufficient/incomplete.): Information requested from the provider was not provided or was insufficient.
CO-163 (Attachment/other documentation referenced on the claim was not received.): The attachment referenced on the claim was not received.

N454 (Incomplete/invalid Consultation Report.): A consultation report was received but was incomplete or invalid.
N181 (Additional information is required from another provider involved in this service.): Additional information is needed from another provider involved in the service.
N706 (Missing documentation.): A general notice that documentation is missing.

N453 FAQ

Do all payers still recognize consultation services?

No. Some payers, including Medicare for most settings, stopped paying consultation codes and expect visits to be billed with other evaluation codes. Other payers and workers' compensation still use them.

Who should send the report?

The consulting provider who billed the service. If the payer is asking the requesting provider for it, that office may need to get a copy from the consultant.

Is a letter to the referring doctor enough?

Often, if it contains the findings, opinion, and recommendations and is signed. Check whether the payer requires particular elements.

Important: read before using this information

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