CPT code 21433: Le Fort III craniofacial separation repair

Key takeaways

CPT code 21433 covers open treatment of a Le Fort III craniofacial separation that is complicated and needs multiple surgical approaches.

The code belongs to the 21431-21436 Le Fort III family and carries a 090 global period.

CPT has no panfacial fracture code, so mandible, zygoma, and frontal bone injuries are reported separately.

Medicare lists 21433 as inpatient-only, so the repair is not payable in an ASC or hospital outpatient department.

Denials cluster on notes that fail to prove comminution, cranial nerve foramina involvement, or multiple surgical approaches.

Practice management software like Pabau keeps the operative note, consents, and images on one patient record for claim support.

CPT code 21433 covers open treatment of a Le Fort III craniofacial separation that is complicated and repaired through multiple surgical approaches. The fracture line separates the midfacial skeleton from the cranial base.

Denials at this level trace back to a thin operative note or a missing modifier. They also follow the wrong pick from the Le Fort III family of five. Claims management software cuts into those denials, but the first line of defense is knowing what the descriptor demands.

This reference covers the official descriptor, RVU structure, accepted modifiers, and paired ICD-10 diagnosis codes. It also covers the global period, documentation requirements, the rest of the Le Fort III family, and the denial patterns that recur.

CPT code 21433: description, code type, and surgical context

CPT code 21433 is a surgical procedure code maintained by the American Medical Association (AMA) under the Current Procedural Terminology (CPT) code set. Its official descriptor reads: Open treatment of craniofacial separation (LeFort III type); complicated (eg, comminuted or involving cranial nerve foramina), multiple surgical approaches.

The 90-day global period bundles all routine follow-up care into the procedure fee. Billing post-operative visits inside that window triggers NCCI bundling edits unless a modifier justifies the separate reporting. Because 21433 sits on Medicare’s inpatient-only list, the same repair performed in an ASC is not payable under the outpatient rules.

What does CPT code 21433 describe?

CPT code 21433 describes the open repair of a Le Fort III craniofacial separation that is complicated and needs multiple surgical approaches. A Le Fort III fracture line runs through the nasal bridge, the medial and lateral orbital walls, and the zygomatic arches.

That fracture line detaches the whole midface from the skull base. CPT therefore calls the injury a craniofacial separation rather than a maxillary or midface fracture.

Two elements separate 21433 from 21432, the base open-treatment code. The fracture must be complicated, meaning comminuted or involving the cranial nerve foramina. The repair must also use multiple surgical approaches, such as coronal, transconjunctival, and intraoral exposures in the same session.

The descriptor says nothing about panfacial injury patterns or facial thirds. Coders sometimes reach for 21433 on any multi-region facial trauma case, and that instinct is wrong. Mandible, zygoma, and frontal bone fractures each carry their own codes, and NCCI edits govern whether they can be reported alongside 21433.

Oral and maxillofacial surgeons and plastic surgeons are the primary reporters, and they often work in tandem on these repairs. Sports medicine and emergency teams usually see the patient first, but the operating surgeon reports the repair. When two surgeons of different specialties each perform a distinct part of the same Le Fort III repair, modifier -62 applies.

Clinical criteria that must be met before CPT 21433 applies:

• The injury is a Le Fort III craniofacial separation, confirmed on CT imaging
• The fracture is comminuted or involves the cranial nerve foramina
• Treatment is open, not closed reduction or interdental wire fixation
• More than one surgical approach is used to expose and reduce the fracture
• The operative note names each approach and each fixation construct applied

Without documented complication and multiple approaches, payers move the claim down to 21432. Without open access, they move it down to 21431.

Reimbursement and RVU structure for 21433

Medicare reimbursement for CPT code 21433 is calculated from the Medicare Physician Fee Schedule (MPFS), which CMS updates annually. The table below explains the RVU structure.

Verify current dollar amounts with the CMS fee schedule tool for the applicable payment year. Rates move each January with the conversion factor.

Use the FastRVU lookup tool to retrieve current work, practice expense, and malpractice RVU values for CPT 21433 by year. Always cite the payment year when you report rates to your billing team or a payer.

Global period and post-operative billing

CPT 21433 carries a 090 global period, so Medicare bundles 90 days of routine post-operative care into the surgical fee. The global surgical package also covers the day before surgery and the day of surgery.

What is bundled during the global period

• Routine post-operative visits related to the fracture repair
• Wound care at plate, screw, and wire sites performed in the office
• Suture and wire removal after the repair
• Treatment of complications that do not require a return to the operating room
• The pre-operative visit on the day before or the day of surgery

What can be billed separately

• An unrelated evaluation and management visit, reported with modifier -24
• An unrelated procedure inside the global period, reported with modifier -79
• A staged or planned second procedure, reported with modifier -58
• A return to the operating room to treat a complication, reported with modifier -78
• The visit at which the decision for surgery was made, reported with modifier -57

Accepted modifiers and when they apply

Modifier applicability for CPT code 21433 is payer-specific. The table below lists modifiers that commonly apply to craniofacial surgical billing. Always confirm against the payer’s current NCCI edits and policy bulletins before you append one.

Modifier -50 (bilateral procedure) does not apply to CPT 21433. A Le Fort III separation crosses the midline and is treated as one craniofacial unit. There is no left or right version of the procedure to report.

ICD-10 codes commonly paired with CPT 21433

Every claim for CPT code 21433 needs a supporting ICD-10 diagnosis that establishes medical necessity. The paired diagnosis must match the clinical documentation and the payer’s coverage policy.

S02.413- is the code for a Le Fort III fracture and is the anchor diagnosis here. Companion S-chapter codes such as S06.309A and S02.32XB often travel on the same trauma claim.

Verify each code against the ICD-10-CM web tool for the applicable fiscal year. ICD-10-CM updates every October 1.

The 7th character describes the fracture, not the surgery. A marks an initial encounter for a closed fracture, and B marks an open one. An open surgical repair of a closed fracture still takes the A extension.

D covers subsequent encounters and S covers sequelae. A code like S02.651K shows how that character shifts once the fracture reaches nonunion.

Documentation requirements for the operative report

Thin documentation is the single largest contributor to denials on CPT code 21433 claims. The operative report has to support every element of the descriptor.

Practices that standardize their operative note templates reduce the variance that triggers medical necessity review. Structured records and digital intake forms both do that job.

The operative report must contain the following elements to withstand a payer audit:

• Fracture pattern named: State that the injury is a Le Fort III craniofacial separation, and cite the CT findings that support that reading.
• Complication documented: Describe the comminution, or the cranial nerve foramina involvement, that makes the case complicated. This is what separates 21433 from 21432.
• Multiple approaches described: Name every approach used, such as coronal, subciliary, transconjunctival, or intraoral. Say what each one exposed.
• Open access confirmed: Describe incision placement and the dissection planes used to reach each fracture site.
• Fixation documented: Specify the type, size, and location of every plate, screw, wire, or mesh construct placed.
• Graft status stated: Say whether bone graft was harvested and placed, because grafting moves the claim to 21436.
• Anesthesia correlation: The anesthesia record must align with the surgeon’s operative time and complexity. Large discrepancies raise flags during audits.
• Co-surgeon rationale (if using modifier -62): Each surgeon’s distinct contribution has to appear in their own report, not in a shared note.

Related CPT codes for Le Fort fracture repair

CPT code 21433 sits in a family of five Le Fort III codes. Picking the wrong one is the most common upcoding or downcoding error in craniofacial billing. Neighboring facial fracture codes turn on the same logic. 21348 covers a nasomaxillary complex fracture repaired with bone grafting, and 21344 covers a complicated frontal sinus fracture.

Two documented facts move a claim from 21432 up to 21433. The fracture has to be complicated, and the repair has to use multiple surgical approaches. Neither is inferred from the injury name alone.

CPT 21435 covers the complicated repair when fixation techniques such as a head cap, halo device, or intermaxillary fixation are used. CPT 21436 covers the complicated multi-approach repair when bone graft is harvested and placed. Reporting either one for a straightforward internal fixation case is an upcoding risk that draws OIG attention.

Bundling rules and NCCI edits

NCCI edits control which additional facial fracture codes can travel on the same claim as 21433. Check the current quarterly edit files before you add a second surgical code.

• Le Fort I and Le Fort II codes describe alternative fracture patterns, so they are not reported with 21433 for the same injury
• Surgical approach work, including the coronal flap, is part of 21433 and is not billed separately
• Mandible and zygomatic arch fractures are separate injuries, so separate codes may apply when the note documents each repair
• Hardware revision inside the global period falls under modifier -58 or -78, depending on why the patient returned
• Graft harvest is built into 21436, so a separate bone graft code such as 20902 is not reported with it
• Closure of the surgical approach is bundled, so a laceration repair code such as 12036 applies only to a separately documented traumatic wound
• When two surgeons split the repair, both report 21433 with modifier -62 rather than dividing the work across different codes

Common billing errors and denial reasons

CPT code 21433 denials cluster around predictable patterns, and most are preventable with a pre-submission checklist. The billing workflows behind low denial rates build these checks in before claims leave the office.

Treating 21433 as a panfacial trauma code

CPT has no single panfacial fracture code, and 21433 is not a stand-in for one. It describes a Le Fort III craniofacial separation only. Reporting it because the patient had fractures across several facial regions is a denial waiting to happen. Without a documented Le Fort III pattern, the claim will not hold up on review.

Reporting 21433 when only one approach is documented

The descriptor requires multiple surgical approaches. A note describing a single coronal exposure supports 21432, not 21433. Payers that review the operative report will downcode the claim, and the difference in payment is significant.

Upcoding to CPT 21435 or 21436

Reporting 21435 or 21436 when the case was a straightforward internal fixation repair is a standing OIG target. The note has to name the external fixation device for 21435, or the graft harvest site and placement for 21436. Without that language, the higher code fails on review.

Insufficient operative report detail

Payers check whether the note names the fracture pattern, each surgical approach, and each fixation construct. A note that says the craniofacial separation was repaired with plates and screws does not clear that bar. It typically returns as a medical necessity denial or a request for additional records.

Missing or incorrect co-surgery documentation

When two surgeons each bill CPT code 21433 with modifier -62, both reports must describe that surgeon’s distinct contribution. A single shared note, or two identical notes, will be denied. Each report should read as a standalone account of that surgeon’s work.

Post-operative visit unbundling during the global period

The 090 global period bundles all routine post-operative visits. Billing an evaluation and management service inside that window needs modifier -24 for an unrelated visit, or modifier -79 for an unrelated procedure. Either one has to be supported by documentation proving the encounter addressed something other than the fracture repair.

Diagnosis code mismatch

Submitting CPT code 21433 with a Le Fort I or Le Fort II diagnosis contradicts the procedure reported. The anchor diagnosis has to be S02.413- for a Le Fort III fracture. If the record supports only a Le Fort I pattern, the correct procedure code sits in the 21421 to 21423 range instead.

How Pabau supports Le Fort III fracture billing

A Le Fort III repair generates paperwork in several places at once. The operative narrative sits in one system, the consent and trauma history in another, and the claim in a third. Details get retyped, and retyping is where the approach list and the fixation detail go missing.

Pabau is an all-in-one practice management system, so the clinical record and the billing side share one patient file. Treatment notes, digital consent forms, and before-and-after images attach to the patient rather than to a folder on someone’s desktop. Pabau Scribe, our AI scribe, captures the clinical narrative while it is still fresh.

Claims management then pulls what is already on that record into a pre-filled claim. You submit and track it without leaving the system. Eligibility checks and remittance posting sit in the same place as the note.

Your coders still choose the code and own the descriptor. What changes is that they stop hunting across systems for the documentation that supports it. A 21433 claim then leaves the practice with its evidence intact.

Keep the operative note and the claim in one place

Pabau keeps operative notes, consents, and images on one patient record. It then pulls that record into a pre-filled claim you submit and track without leaving the system.

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Conclusion

Choosing 21433 is the easy half of the claim. The operative note carries the rest, because it has to prove comminution or foramina involvement and name every approach used. Site of service settles the other half, since the repair is inpatient-only.

Get those facts on the page, pair the claim with S02.413-, and respect the 090 global period. Practice management software like Pabau keeps the operative note, the consents, and the images on one patient record. The evidence for a 21433 claim then sits in one place. To see how Pabau supports craniofacial billing teams, book a demo.

Continue your research

Is the injury a Le Fort II pattern instead? CPT code 21348 covers open treatment of a nasomaxillary complex fracture with bone grafting, including RVUs, modifiers, and documentation.

Repairing a frontal sinus fracture in the same patient? CPT code 21344 walks through the complicated open repair, the documentation it needs, and the codes it should not travel with.

Nasal septum involved in the injury pattern? CPT code 21336 sets out when open treatment of a nasal septal fracture is billable and how to word the operative note.

Coding the mandible side of a panfacial case? ICD-10 code S02.600D explains the mandible body fracture descriptor and how the 7th character tracks routine healing.

Planning a later corrective osteotomy? CPT code 21196 covers mandibular osteotomy billing, from the RVU structure to the documentation payers ask for.

Frequently asked questions