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N308 Remark Code: Appliance Placement Date Invalid

N308 means the date an appliance was placed was missing, incomplete, or invalid. This typically involves orthodontic appliances or dental prosthetics, where the placement date drives benefit periods and payment schedules.

Quick facts

Code
N308 (RARC N308)
Status
Active In use since December 2, 2004.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The dental provider must correct the placement date; the patient is not liable for this adjustment.
Official description
Missing/incomplete/invalid appliance placement date.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N308 means

Orthodontic appliances, dentures, bridges, and similar devices have lasting benefit implications. Plans often schedule orthodontic payments from the date the appliance was placed, and they use placement dates to enforce replacement frequency limits for prosthetics. N308 means the payer didn’t receive a usable placement date.

It usually rides with CARC 16. Correcting it lets the payer calculate benefits properly.

Common causes

  • The orthodontic section of the claim was left incomplete, with the treatment indicator marked but no placement date.
  • The date reported was the consultation or records date rather than the date the appliance was actually placed.
  • A claim for ongoing orthodontic treatment carried the date of the current adjustment visit instead of the original placement.
  • The placement date is later than the date of service on the claim.
  • The practice transitioned systems and historical placement dates weren’t migrated.

How to fix it

  1. Check the treatment record for the date the appliance was placed or the patient was banded.
  2. Enter that date in the placement field of the dental claim, keeping it separate from the current date of service.
  3. If you are also reporting remaining treatment months, make sure they are consistent with the placement date.
  4. Resubmit the corrected claim according to the dental payer’s correction process.

How to prevent it

Store the placement date once in the patient’s treatment plan and have every subsequent orthodontic claim pull it automatically. For prosthetics, record prior placement dates at intake, since the payer will check replacement intervals. Periodic review of dental remits by remark, as described in our CARC and RARC guide, shows whether N308 is tied to one workflow.

Codes that may appear with N308

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Missing or invalid information; N308 identifies the appliance placement date.
  • N786 (Benefit limitation for the orthodontic active and/or retention phase of treatment.): A benefit limitation applies to the orthodontic active or retention phase.
  • N333 (Missing/incomplete/invalid prior placement date.): The prior placement date is missing or invalid.
  • N336 (Missing/incomplete/invalid replacement date.): The replacement date is missing or invalid.

N308 FAQ

Where is the appliance placement date reported?

On dental claims, the ADA claim form's orthodontic section asks for the date the appliance was placed. Electronic dental claims have a matching date field.

Why does the placement date matter for orthodontics?

Many plans pay orthodontic benefits in installments that start from the banding or placement date, so the payer needs it to calculate what is due.

What if treatment started under a different plan?

Report the actual placement date. The new plan may apply its own rules for treatment already in progress, which vary by plan.