D4240 Dental Code: Gingival Flap Surgery (4+ Teeth) Guide

What D4240 covers

D4240 reports a gingival flap procedure with root planing on four or more contiguous teeth or tooth-bounded spaces within a single quadrant. The dentist raises a soft-tissue flap to expose the root surfaces and the surrounding pocket, removes granulation tissue, planes the roots clean under direct vision, and closes the flap. The root planing is part of the procedure and the fee. It is the surgical step for periodontitis that nonsurgical therapy did not resolve, where pockets are too deep to clean the roots thoroughly without opening the tissue.

It does not cover:

• The same flap procedure on one to three teeth in a quadrant. That is D4241.
• A flap that also reshapes or removes bone. That is osseous surgery, D4260 (four or more teeth) or D4261 (one to three teeth).
• Nonsurgical scaling and root planing with no flap. That is D4341 (four or more teeth) or D4342 (one to three teeth).
• A gingivectomy or gingivoplasty, which removes or recontours gum tissue rather than raising a flap for root access. That is D4210 (four or more teeth) or D4211 (one to three teeth).
• A separate charge for the root planing on the same teeth. It is included in D4240.

When to bill D4240

Bill D4240 when:

• A soft-tissue flap is raised for access on four or more contiguous teeth or tooth-bounded spaces in one quadrant.
• The roots are planed under direct vision and the flap is closed.
• No bone is reshaped or removed.
• The periodontal charting and diagnosis support surgical access rather than another round of nonsurgical cleaning.

Count per quadrant

Four or more contiguous teeth or tooth-bounded spaces in one quadrant is D4240; one to three is D4241. The count is per quadrant, so teeth in different quadrants are never added together to reach four. Three teeth in one quadrant and three in the next are two separate D4241 claims, not one D4240. Getting the count wrong is the most common coding error on this pair.

Gingival flap versus scaling and root planing versus osseous surgery

Three periodontal procedures sit next to each other in the treatment sequence. What separates them is what the surgeon did with the flap and the bone.

• Scaling and root planing (D4341, D4342) is nonsurgical, with no flap raised. It is usually the first phase of periodontal therapy, done to treat active disease and re-evaluated afterward.
• Gingival flap with root planing (D4240, D4241) raises a flap so the roots can be cleaned under direct vision when pockets are too deep for closed instrumentation, then closes it. It does not touch bone.
• Osseous surgery (D4260, D4261) raises a flap and reshapes or removes bone to correct the defects periodontal disease left behind, then closes. It carries its own fee and documentation.

A claim coded in the wrong category, in either direction, gives a reviewer a reason to downgrade or deny.

Top reasons D4240 gets denied or downgraded

1. Downgrade to scaling and root planing. The most common problem. When the operative note does not clearly document that a flap was raised, many plans reprocess D4240 at the D4341 allowable.
2. No nonsurgical therapy on file first. Many plans expect documented scaling and root planing and a re-evaluation before they consider surgical access, and pend or deny surgery without it.
3. Wrong count. D4240 billed when only three teeth were treated reads as upcoding; a genuine four-tooth quadrant split into D4241 claims underpays the practice.
4. Frequency limit on the quadrant. Plans that cover periodontal surgery often limit it to once per quadrant within a defined window, and a repeat inside that window denies.
5. Charting that does not justify surgery. Carriers want recent charting with pocket depths deep enough to support opening the tissue.

Documentation that supports the claim

The claim needs:

• Recent periodontal charting, usually within six months, showing pocket depths that justify a surgical flap. Attach it to the claim, not just the record.
• A diagnosis of periodontitis.
• The teeth treated and the quadrant, so the count that separates D4240 from D4241 is on the record.
• Radiographs showing the bone loss.
• Evidence that nonsurgical therapy, typically scaling and root planing, was done and re-evaluated, and that residual disease remained.

The operative record should describe the flap elevation and the root planing and state that no bone was reshaped. The flap is what lifts this above scaling and root planing, and the absence of bone work keeps it below osseous surgery.

Example case

A 54-year-old patient completed scaling and root planing in the upper right quadrant three months ago. At the re-evaluation, the chart shows residual pockets of 5 to 6 mm on teeth #2, #3, #4, and #5. The periodontist raises a soft-tissue flap across those four contiguous teeth, planes the exposed roots, and closes. No bone is recontoured.

Billing for the visit:

1. Before scheduling, confirm the plan’s periodontal surgery benefit, its requirement for completed nonsurgical therapy, and any frequency limit on the quadrant.
2. Report D4240 on the upper right quadrant for teeth #2 through #5, because four contiguous teeth were treated with a flap.
3. Do not add D4341 for the same teeth on this date. The root planing is included in D4240.
4. Attach the periodontal charting showing the residual pockets, the diagnosis, and recent radiographs.
5. Add a one-line narrative: “Gingival flap with root planing, upper right quadrant, teeth #2 to #5, for residual pockets after completed SRP and re-evaluation. No osseous involvement.”
6. If the EOB reprocesses at the D4341 allowable, check whether the flap was clearly documented before appealing.