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N930 Remark Code: Missing or Invalid Quadrant

N930 means the quadrant identifier on the claim was missing, incomplete, or invalid. Procedures performed by quadrant, such as periodontal scaling and root planing, must state which part of the mouth was treated so the payer can check frequency limits and duplicates.

Quick facts

Code
N930 (RARC N930)
Status
Active In use since July 1, 2026.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The unpaid amount due to the claim data error. The office corrects it; the patient is not billed.
Official description
Missing/Incomplete/Invalid quadrant identifier.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N930 means

N930 is about a claim field, not an attachment. Some dental procedures are defined by an area of the mouth rather than a single tooth, most often a quadrant. The payer needs that area on each line to price the service, apply frequency limits, and avoid paying twice for the same area.

N930 means the quadrant was left blank, entered in the wrong field, or reported with a value that does not fit the procedure.

Common causes

  • The quadrant field was blank because the office entered tooth numbers only.
  • A full-arch or whole-mouth code was used where a quadrant was required.
  • Several quadrants were combined on one line.
  • The software sent a quadrant value in a format the payer does not accept.

How to fix it

  1. Review the chart to confirm which quadrant or quadrants were treated.
  2. Enter the correct area of the oral cavity code on each line.
  3. Split multi-quadrant services into separate lines if needed.
  4. Submit a corrected claim according to the payer’s rules, and include periodontal charting if the payer also requires it.

How to prevent it

Set up claim edits in your dental software that require an area of the oral cavity for quadrant-based procedures, and train staff to chart the quadrant at the time of treatment.

Codes that may appear with N930

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim has a submission or billing error; N930 points to the quadrant.
  • CO-4 (The procedure code is inconsistent with the modifier used.): The procedure code is inconsistent with the modifier or area reported.
  • N37 (Missing/incomplete/invalid tooth number/letter.): The tooth number or letter, rather than the quadrant, is missing or invalid.
  • N75 (Missing/incomplete/invalid tooth surface information.): The tooth surface is missing or invalid.
  • N39 (Procedure code is not compatible with tooth number/letter.): The procedure code is not compatible with the tooth number or letter.

N930 FAQ

What are the quadrant values?

Dental claims use area of the oral cavity codes. The quadrants are 10 for upper right, 20 for upper left, 30 for lower left, and 40 for lower right. Other values cover the entire mouth or a full arch.

Which procedures need a quadrant?

Services performed by quadrant, such as scaling and root planing and some periodontal surgeries. The payer's rules and procedure code descriptions show which ones.

What if I treated two quadrants?

Report each quadrant on its own line with its own identifier, unless the payer instructs otherwise.