D4240Gingival Flap Procedure Including Root Planing, Four or More Contiguous Teeth Per Quadrant

What This Code Covers

D4240 covers a surgical gingival flap procedure on a quadrant involving four or more contiguous teeth. The dentist or periodontist makes an incision in the gum tissue, lifts (reflects) a flap to expose the root surfaces and underlying bone, then performs thorough root planing and debridement of the area. The flap is repositioned and sutured. This procedure is used for advanced periodontal disease that has not responded adequately to non-surgical scaling and root planing alone. It allows direct visualization and access to deep pockets, root defects, and bone irregularities that cannot be reached with closed (non-surgical) instruments.

Billing Guide

Bill this code when:

• Patient has advanced periodontitis that did not respond to non-surgical scaling and root planing (D4341/D4342)
• Four or more contiguous teeth in the quadrant are involved in the surgical site
• The procedure includes incision, flap reflection, root planing under direct vision, and suturing
• Re-evaluation after SRP showed persistent deep pockets (typically 5mm or greater) or continued bone loss

Do not bill this code when:

• Non-surgical scaling and root planing has not yet been attempted. Most payers require SRP before approving surgery
• Fewer than four contiguous teeth are involved. Use D4241 (gingival flap, 1-3 teeth)
• The procedure is clinical crown lengthening for restorative purposes. Use D4249
• The surgery is osseous (bone recontouring) in nature. Use D4260 or D4261 (osseous surgery codes)

Insurance and Denial Prevention

Key Payer Rules:

• Classified as a major service, typically covered at 50% after deductible
• Most payers require that non-surgical treatment (SRP) was attempted first and documented as insufficient
• Pre-authorization is commonly required. Submit the request before scheduling surgery
• Many plans have a waiting period of 6-12 months for major periodontal services on new policies
• Some payers limit periodontal surgery to once per quadrant per lifetime or per 36-month period

Common Denials and How to Respond:

• No prior non-surgical treatment documented -> Submit records showing the dates and outcomes of prior scaling and root planing (D4341/D4342), including post-SRP re-evaluation charting that demonstrates the need for surgical intervention.
• Not medically necessary -> Provide pre-operative charting with pocket depths of 5mm or greater, radiographs showing bone loss, and a narrative explaining that the patient failed to respond to non-surgical therapy. Include the re-evaluation findings after SRP.
• Pre-authorization not obtained -> If surgery was performed without pre-authorization, submit a retroactive request with full clinical documentation. Include a letter explaining the urgency if applicable. Some payers will process retroactive requests, but approval is not guaranteed.
• Downgraded or bundled with other procedures -> If the payer bundles D4240 with other periodontal codes billed the same day, appeal with documentation showing that each procedure was distinct and necessary. Provide operative notes for each service.