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N402 Remark Code: Incomplete Periodontal Charting

N402 means the dental payer received periodontal charting, but it was incomplete or invalid, for example missing pocket depths for the treated areas, undated, or too old, so it could not support the periodontal service.

Quick facts

Code
N402 (RARC N402)
Status
Active In use since August 1, 2007.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim remains denied until usable charting is received or the decision is overturned. The patient is not billed for this adjustment.
Official description
Incomplete/invalid periodontal charting.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N402 means

A dental reviewer opened the periodontal chart you sent and couldn’t use it to approve the claim. Something was missing, unreadable, out of date, or didn’t match the treatment billed. N402 is the code for that result.

It commonly appears with CARC 251, or with CARC 50 when the chart was complete but didn’t support the treatment.

What goes wrong with perio charts

  • Partial readings. Depths recorded for some teeth but not the quadrants treated.
  • No date, or a date long before the treatment.
  • Export issues. The printout lacks the patient’s name or is cut off.
  • Mismatch with the claim. The treated quadrants on the claim don’t correspond to the areas with charted disease.
  • Legibility. Handwritten or low-resolution scans.

Getting the claim reprocessed

  1. Read the plan’s explanation to see which element was lacking.
  2. Pull the complete chart from the pre-treatment exam, with all six-point readings (or whatever the plan requires) for the treated teeth.
  3. Make sure the quadrants on the claim line up with the charted disease and the radiographs.
  4. Add a short narrative summarizing the diagnosis and the rationale for the procedure.
  5. Resubmit the attachment or request reconsideration, referencing the claim number.

How to prevent it

Chart all teeth at every periodontal evaluation and date each chart. Before submitting perio claims, verify that the attachment is the pre-treatment chart and includes readings for every quadrant billed.

Codes that may appear with N402

  • CO-251 (The attachment/other documentation that was received was incomplete or deficient.): The attachment received was incomplete or deficient.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Not deemed medically necessary, when the charting doesn't show the disease level the plan requires.
  • N401 (Missing periodontal charting.): Used when no periodontal charting was received at all.
  • N682 (Missing/Incomplete/Invalid history of prior periodontal therapy/maintenance.): Covers missing or invalid history of prior periodontal therapy or maintenance.
  • N205 (Information provided was illegible.): Says the information provided was illegible.

N402 FAQ

What do reviewers look for in the chart?

Pocket depth readings for the teeth treated, usually multiple sites per tooth, plus the exam date and patient identifiers. Some plans also look for bleeding, recession, or attachment levels.

Can I re-chart the patient and send new charting?

New charting taken after treatment doesn't reflect the condition before treatment. Send the pre-treatment chart, and add a narrative if details are missing.

What if the chart shows depths below the plan's threshold?

Then the plan may consider the procedure not necessary. An appeal would need other clinical evidence supporting treatment.