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N481 Remark Code: Required Models Missing

N481 means the payer needed models, such as casts or impressions used to evaluate a service, to adjudicate the claim, and they were not received. It is a documentation request; the claim is held or denied until the models are supplied.

Quick facts

Code
N481 (RARC N481)
Status
Active In use since July 1, 2008.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The service was denied or pended for missing supporting records that the provider can supply. It is not shifted to the patient.
Official description
Missing Models.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N481 means

Some services are easier to review from a physical or digital model than from notes: a cast that shows the shape of a dental arch, for example, or a record of the anatomy a custom device was built to fit. N481 tells you the payer’s reviewer wanted such models and none were on file for the claim.

Unlike N477, the official text does not limit the remark to dentistry. Read it together with the reason code and the service line it is attached to, since that tells you which procedure the payer is reviewing.

Common causes

  • The payer’s policy requires models for this service and the claim was sent without them.
  • The claim said attachments would follow, but they were never submitted.
  • The models were mailed or uploaded but not linked to the correct claim.
  • A records request from the payer went unanswered.

What to do

  1. Identify the line and procedure the remark is attached to on the remittance.
  2. Confirm what the payer needs. Ask whether it wants physical casts, scans, or photographs, and where to send them.
  3. Label the submission with patient name, member ID, dates of service, and the payer’s claim number.
  4. Submit the models through the payer’s attachment or records process. If the payer closed the claim, follow its instructions for a corrected claim or reconsideration.
  5. Record the submission date and follow up if the claim has not been reprocessed within the payer’s stated review time.

How to prevent it

Note which services each payer reviews with models and attach them the first time. Treat model requests like any other records request: log them, assign an owner, and track them to completion. The authorization and documentation prevention guide covers building that kind of front-end checklist.

Codes that may appear with N481

  • CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): An attachment is required; the remark says the attachment is a set of models.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim lacked information needed to adjudicate it.
  • CO-226 (Information requested from the Billing/Rendering Provider was not provided or not provided timely or was insufficient/incomplete.): Used when the payer asked the provider for the models and did not get them in time.
  • N477 (Missing Dental Models.): The dental-specific version of this remark.
  • N482 (Incomplete/invalid Models.): Models were received but were incomplete or invalid.
  • N706 (Missing documentation.): A general missing-documentation remark when the payer does not name the document.

N481 FAQ

How is N481 different from N477?

N477 specifically says dental models. N481 just says models, so payers can use it for any service where casts or similar records support the claim. In practice most payers that send it are dental plans.

What if I don't know which models the payer wants?

Call the payer and ask which service line triggered the request and what format it accepts. Sending the wrong records can lead to a second denial.

Does N481 change the patient's balance?

Not by itself. The service has not been adjudicated yet, so there is no patient responsibility to bill until the payer reviews it.