D4342Periodontal Scaling and Root Planing, One to Three Teeth Per Quadrant

What This Code Covers

D4342 covers scaling and root planing (SRP) on a quadrant where only one to three teeth require subgingival treatment for periodontal disease. The procedure is identical to D4341 in technique. The hygienist or dentist removes calculus, plaque, and bacterial toxins from root surfaces below the gum line. The distinction is purely about the number of teeth involved in that quadrant. Reimbursement for D4342 is lower than D4341 because fewer teeth are being treated.

Billing Guide

Bill this code when:

• Patient has a diagnosis of periodontitis and one to three teeth in the quadrant show clinical attachment loss and bone loss
• Probing depths around the affected teeth are generally 4mm or greater with bleeding on probing
• The remaining teeth in the quadrant are healthy and do not require subgingival scaling
• Current radiographs support the localized nature of the disease in that quadrant

Do not bill this code when:

• Four or more teeth in the quadrant require scaling and root planing. Use D4341
• Patient has gingivitis only with no attachment loss or bone loss. Use D1110 (prophylaxis)
• Patient is returning for maintenance after completing active periodontal therapy. Use D4910
• You are performing gross debridement to enable a comprehensive evaluation. Use D4355

Insurance and Denial Prevention

Key Payer Rules:

• Covered as a basic or major service, typically at 60-80% depending on the plan
• Many payers limit SRP to once per quadrant every 24 months, same as D4341
• Some payers require that the specific tooth numbers be listed, not just the quadrant
• D4342 and D4341 should not be billed on the same quadrant on the same date of service
• Reimbursement is lower than D4341, so make sure you are coding the correct number of teeth

Common Denials and How to Respond:

• Insufficient documentation -> Resubmit with tooth-specific periodontal charting, radiographs, and a narrative explaining the localized disease pattern. List the exact tooth numbers treated.
• Should be D4341 -> If the payer questions why D4342 was used instead of D4341, respond with charting showing that only 1-3 teeth in the quadrant had disease. This actually saves the payer money, so appeals are usually straightforward.
• Not medically necessary -> Provide pocket depth measurements, bleeding on probing data, radiographic evidence of bone loss around the specific teeth, and a diagnosis of localized periodontitis.
• Frequency exceeded -> Verify the date of the last SRP on that quadrant. If it was under a different plan or provider, submit a letter of explanation with supporting records.