D4264 Dental Code: Additional Bone Graft Site Billing Guide

What D4264 covers

D4264 reports a bone replacement graft placed around a natural tooth that is staying in the mouth, for each site treated after the first one in that quadrant. The procedure it describes is identical to D4263. Periodontal disease has hollowed out the bone against the root, the surgeon opens the site and cleans it, and graft material goes into the defect so bone can rebuild. D4264 exists only so the claim can carry how many defects were treated.

That makes it a counting code, and three things follow from it:

• It never stands alone. An additional site presumes a first site. D4263 has to be on the claim for the same quadrant.
• The count resets at every quadrant boundary. Two quadrants of regenerative surgery produce two D4263 lines, not one, plus whatever D4264 lines each quadrant earns.
• It carries the same exclusions as the first-site code. Flap entry and closure, wound debridement, osseous contouring, the barrier membrane, and any biologic material are all outside the fee. The site also has to have a natural tooth at it, which rules out an extraction site or an edentulous space.

Both codes are active in CDT 2026. Each took an editorial action in the 2026 code set, which tidies the entry rather than changing what the procedure is, so the meaning that applied last year still holds.

A site is a defect, not a tooth

This is the whole page. Billers count teeth because teeth are what the claim form asks for, and the code counts bony defects.

The American Academy of Periodontology’s coding guidance sets the test at whether the defects communicate:

1. Two contiguous teeth, two separate osseous defects. Two sites. D4263 for the first, D4264 for the second.
2. Two contiguous teeth, one defect continuous through the interproximal bone. One site. D4263 only, with no D4264, even though two teeth were involved and two roots got graft material packed against them.
3. Three separate defects in one quadrant. D4263 once, D4264 twice.
4. The same three defects split across two quadrants. D4263 in each quadrant, D4264 for the remainder in each.

Case two is the one that costs money in both directions. Billed as two sites, the D4264 line gets denied and the claim gets a records request. Billed as one site when the defects were genuinely separate, the practice writes off a line it earned.

Two counting patterns on the same claim

A regenerative surgery usually places a graft, a membrane, and sometimes a biologic at the same defect. Those three families count differently, and a claim that applies one pattern to all of them is wrong somewhere.

• The bone graft sequences within the quadrant. D4263 first, D4264 for each site after it.
• The membranes do not sequence. D4266 for a resorbable barrier and D4267 for a non-resorbable barrier are each reported per site. There is no additional-site membrane code. A second membraned site in the same quadrant is another D4266 or D4267 line.
• Biologic materials do not sequence either. D4265 is per site.

So a quadrant with three grafted and membraned defects using resorbable barriers is D4263, D4264, D4264, D4266, D4266, D4266. One code changes on the second site, the other does not.

The surgical access code counts on a third axis again. Osseous surgery is scoped by teeth per quadrant, D4260 for four or more and D4261 for one to three, as is a gingival flap procedure with root planing, D4240 or D4241. A quadrant can legitimately carry D4261 for two teeth alongside three graft sites, because teeth and defects are not the same unit.

Grafts that are not D4264

Every code below puts bone in the jaw. What separates them is the state of the tooth and the surgery the graft belongs to.

• D4264 is a periodontal graft around a tooth that is staying, at a site after the first in the quadrant.
• D7953 is a graft into a socket at the time an extraction or implant removal is done. It is reported per site with no first-versus-additional split.
• D6104 is a graft placed at the same visit as an implant.
• D7950 is a staged augmentation of an edentulous ridge, with no extraction and no same-day implant.
• D3428 is a graft placed with periradicular surgery, with D3429 for each additional contiguous tooth in the same surgical site.

An appointment can produce more than one of these. A quadrant of periodontal surgery that also removes one hopeless tooth carries D7953 in the empty socket and D4263 plus D4264 around the teeth that stayed. Code each graft against the tooth beside it, not against the visit.

Coverage and how carriers treat it

Plans that cover periodontal surgery generally cover D4264 on the same terms as the first site, and it is reviewed line by line rather than as an add-on that rides along.

The defect standard applies to every line. Cigna’s 2026 DPPO guidelines describe the benefit as available where the pocket measures 5 mm or deeper with bone loss and a vertical bony defect next to the retained natural tooth. UnitedHealthcare’s bone replacement graft policy, effective May 2026, names intrabony vertical defects and Class II furcation involvements as the indications and excludes non-vertical defects, teeth with a hopeless prognosis, and grafts done with periradicular surgery. Horizontal bone loss is the more common radiographic pattern and does not meet either standard, so a second site has to clear the vertical test on its own.

Retreatment windows are scoped to the site. Cigna’s guidelines treat a repeat graft by the same office at the same tooth or site within 36 months as the practice’s cost, not billable to the patient. Because the window follows the site rather than the quadrant, a later graft at a defect that was never treated before can still be payable in a quadrant that has history. Document which site is new.

Patient history gets read. The UnitedHealthcare policy also excludes patients who were non-compliant with prior periodontal therapy or who present with poor oral hygiene. A chart showing scaling and root planing, then a re-evaluation that documents the residual defects, reviews cleanly. Grafting as the first periodontal treatment on file does not.

Thresholds, frequency windows, and whether a plan pays more than one regenerative procedure per site per date are all plan-dependent. Verify them before the surgical appointment, not after the denial.

Documentation that supports the claim

UnitedHealthcare’s 2026 claim review guidelines ask for the same three attachments on D4264 as on D4263: current dated pre-operative radiographs of the area, complete six-point periodontal charting, and a narrative of necessity. Build the packet that way by default.

• Radiographs showing each vertical defect, covering every site billed rather than just the first. The periapical that demonstrates the intrabony component answers the vertical-versus-horizontal question directly.
• Six-point charting at the grafted teeth, recent enough that the pocket depths still reflect the surgical findings.
• A narrative naming each defect by tooth and surface, with the wall count and a statement of whether adjacent defects communicate. This is the sentence that supports the site count.
• The graft material, membrane, and biologic, listed per site.
• The prior nonsurgical therapy and the re-evaluation that found the defects still present.

What to get right in your PMS

The screens differ across Open Dental, Dentrix, Eaglesoft, Curve, and Carestream, but the setup that prevents these denials does not:

1. Stop per-tooth posting on periodontal surgery. Templates that fan a procedure out across every tooth in the quadrant will post four D4263 lines where the correct claim is one D4263 and three D4264.
2. Attach the quadrant to every graft line. The sequence is quadrant-scoped, so a claim with no quadrant on the graft lines cannot be adjudicated the way the code is written.
3. Enter D4264 as separate lines with their own tooth numbers where the system allows it, rather than one line with a quantity. Carriers vary on how they read quantity on a site-counted code, and separate lines give you something specific to appeal.
4. Keep the membrane and biologic codes adjacent to the graft codes in the pick list. D4266, D4267, and D4265 get skipped when they are three menus away, and the surgery goes out underbilled.
5. Flag the surgical access code as required with any graft line. A graft with no flap or osseous code beside it is the pattern most likely to come back as a records request.

For how the tooth numbers, quadrants, and the remarks field are filled in on the claim itself, see the ADA dental claim form guide.