D4240 is the CDT code for a gingival flap procedure, including root planing, on four or more contiguous teeth (or tooth-bounded spaces) in a quadrant — elevating a soft-tissue flap to access and clean root surfaces in deeper periodontal pockets, without reshaping bone.
Informational only — confirm the official CDT descriptor and your payers' rules independently. This is general guidance, not billing, coding, or clinical advice.
When to Use the D4240 Code
Report D4240 when a soft-tissue flap is elevated to gain access to root surfaces for debridement and root planing across four or more contiguous teeth in a quadrant, typically when non-surgical scaling and root planing alone could not resolve deeper pockets. The flap is reflected, the roots are cleaned under direct vision, and the tissue is sutured back — but no osseous (bone) recontouring is performed.
The companion code is D4241 for one to three teeth in a quadrant. The most important contrast is with osseous surgery (D4260): D4260 includes reshaping bone, while D4240 does not. D4240 is also distinct from non-surgical SRP (D4341) and from a gingivectomy (D4210), which removes tissue rather than reflecting a flap.
Documentation & Clinical Scenarios
A flap procedure claim must show why surgical access was needed and confirm no bone work was done:
- The teeth and quadrant(s) treated, confirming four or more contiguous teeth per quadrant.
- Pre-surgical periodontal charting showing residual deep pockets after initial therapy.
- Radiographs documenting the periodontal condition, and the periodontal diagnosis.
- A narrative noting prior non-surgical therapy, the residual pocket depths, and that the procedure was flap access with root planing only (no osseous recontouring).
Bone grafts, biologic materials, or osseous recontouring, if performed, change the code and are documented and billed separately.
Insurance & Billing Tips
- Verify surgical periodontal benefits first. Confirm coverage, waiting periods, and whether a pre-treatment estimate is recommended.
- Bill by quadrant. Each quadrant with four or more contiguous teeth is its own D4240 line; one to three teeth use D4241.
- Show prior therapy. Many payers expect documented scaling and root planing and a re-evaluation before approving surgical flap access.
- Distinguish from osseous surgery. Make clear no bone was reshaped, or the claim may be questioned against D4260.
- Appeal with charting. Pre- and post-therapy probing depths plus radiographs support an appeal if the claim is denied.
Example Case
A 58-year-old patient completed scaling and root planing three months ago but still has 6 mm pockets with bleeding on the upper right molars and bicuspid. Charting and radiographs confirm residual deep pockets across four contiguous teeth. The dentist elevates a flap, planes the exposed root surfaces under direct vision, and sutures the tissue without reshaping bone — reported as D4240 for that quadrant. The narrative documents the prior non-surgical therapy and residual pocket depths, and the claim is approved.
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Frequently Asked Questions
What's the difference between D4240 and D4260?
Both are surgical periodontal procedures that elevate a flap, but the difference is bone. D4240 is a gingival flap with root planing and no osseous recontouring, while D4260 (osseous surgery) includes reshaping the bone. Choosing between them depends on whether bone was modified during the procedure. Reporting D4240 when osseous work was done — or vice versa — leads to denials, so the operative note must match the code.
Is D4240 the same as a deep cleaning?
No. A deep cleaning, scaling and root planing (D4341), is non-surgical and done without reflecting a flap. D4240 is a surgical procedure: the gum tissue is elevated to access root surfaces under direct vision, then sutured back. It is typically used when non-surgical therapy could not resolve deeper pockets, and most payers expect prior SRP and a re-evaluation in the record.
Will insurance cover a gingival flap procedure?
Many plans cover D4240 when documentation shows residual deep pockets after non-surgical therapy, supported by charting and radiographs. Coverage often depends on demonstrating that scaling and root planing was performed first and that pockets persist. Verify the plan's surgical periodontal benefits, any waiting period, and documentation requirements before treatment, since rules vary.
Does D4240 require pre-authorization?
A pre-treatment estimate is commonly recommended because surgical periodontal claims are reviewed closely. Submitting periodontal charting, radiographs, and a narrative noting prior therapy and residual pockets confirms medical necessity, establishes the patient's remaining benefit, and reduces the chance of a denial or a surprise balance.
Confirm the current CDT descriptor and your specific payer policies before billing — browse the full dental code library or see our insurance verification feature.