21436

⚕️CPT Code 21436 — Open Treatment of Craniofacial Separation (LeFort III), Complicated

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📋 Official Code Descriptor

Open treatment of craniofacial separation (LeFort III type); complicated, multiple surgical approaches, internal fixation, with bone grafting (includes obtaining graft)

Descriptor Update

The short descriptor for 21436 was revised effective 2025-01-01. Always confirm you are referencing the current AMA CPT edition.

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🧠 Clinical Overview

A Le Fort III fracture — also called craniofacial disjunction — is the most severe pattern of midface fracture. The fracture line runs parallel to the skull base, effectively separating the entire midfacial skeleton from the cranial vault. It transects the naso-orbito-ethmoid (NOE) complex, the lateral orbital walls, and the zygomatic arches, and invariably involves the pterygoid plates of the sphenoid bone._{StatPearls, Le Fort Fractures 2024}

CPT 21436 captures the most complex tier of open Le Fort III repair:

• Multiple surgical approaches — typically a coronal (bicoronal scalp) incision combined with transoral and/or subciliary/transconjunctival incisions to provide simultaneous access to the upper, mid, and lower fracture lines
• Internal fixation — titanium miniplates and/or lag screws applied across osteotomy/fracture sites to restore rigid skeletal stability
• Bone grafting — autogenous bone harvested from a donor site (cranial outer table, iliac crest, rib) or allograft used to fill comminuted gaps and reconstruct buttresses; graft harvest is bundled within this code per the descriptor
• Complicated qualifier — implies comminution, skull base involvement, prior surgical failure, concomitant NOE complex fracture, or the need for staged or simultaneous craniofacial osteotomies (e.g., Le Fort I or Le Fort II-level osteotomies performed in the same setting as the Le Fort III repair)

Anatomic Structures Addressed

The procedure involves the nasomaxillary buttresses, zygomaticofrontal suture, zygomaticomaxillary complex, orbital floors and walls, nasal bones, ethmoid complex, pterygoid plates, and potentially the anterior cranial base/floor.

CSF Leak Risk

Due to the proximity of the fracture plane to the anterior skull base, Le Fort III injuries carry a significant risk of cerebrospinal fluid (CSF) leak (rhinorrhea) and associated pneumocephalus. Neurosurgical consultation and co-management are common in these cases._{StatPearls 2024}

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💰 Fee Schedule & Valuation

Field	Value
wRVU	~34.57 (verify vs. current CMS MPFS RVU file)
Global Period	090 days
Assistant Surgeon Payable	✅ Yes
Co-Surgery Payable	✅ Yes — -62 commonly applicable
Team Surgery Payable	✅ Yes — -66 applicable when 3+ surgeons required
Bilateral Surgery	❌ Not applicable (procedure is inherently bilateral)
Multiple Procedure Reduction	Applies — 50% reduction on secondary procedures per Medicare MPFS
Modifier 51 Exempt	❌ No
Medicare Status Indicator	Active — payable

wRVU Context

For reference, CPT 21431 (Le Fort III, simple, no internal fixation) carries substantially fewer wRVUs. The jump from 21435 (complicated, internal fixation only) to 21436 (complicated, internal fixation plus bone graft) reflects additional operative time, technical complexity, and donor site management.

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🌳 Code Tree — Le Fort III Family (21431-21436)

Code Selection Logic

Choose the code that reflects the highest level of complexity documented in the operative report. The “complicated” designation (21433-21436) requires documentation of skull base involvement, comminution, or multiple osteotomy levels.

Open Treatment of Craniofacial Separation — LeFort III Type
│
├── 21431 — Without internal fixation
│       ↳ Simple Le Fort III; no hardware applied
│
├── 21432 — With internal fixation
│       ↳ Simple Le Fort III; titanium plates/screws applied
│
├── 21433 — Complicated; without internal fixation
│       ↳ Comminuted, skull base, or multi-level; no hardware
│
├── 21434 — Complicated; with bone grafts
│       ↳ Comminuted/multi-level; bone graft, no fixation hardware
│
├── 21435 — Complicated; with internal fixation
│       ↳ Comminuted/multi-level; hardware, no bone graft
│
└── 21436 — Complicated; with bone grafts AND internal fixation ✅ (THIS CODE)
        ↳ Most complex tier — multi-approach, hardware, bone graft bundled

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✅ Included in 21436 (Bundled — Do NOT Report Separately)

The following are considered integral components of the procedure and are not separately reportable:

• Coronal scalp incision and subperiosteal elevation
• Transoral incisions (gingivobuccal sulcus approach)
• Intermaxillary fixation (IMF) / arch bar application performed as part of this procedure
• Application of titanium plates, screws, and/or wire fixation
• Bone graft harvest — the descriptor explicitly states “includes obtaining graft”; the harvest of autogenous bone (e.g., from the cranial outer table or local donor site) is bundled
• Standard wound closure

Bone Graft Harvest from Distant Donor Site

If bone is harvested from a separate, distant anatomic site (e.g., iliac crest via a separate incision), some payers may allow separate reporting of 20902 (bone graft, major/large) or 20900 (bone graft, minor) in addition to 21436. However, this is payer-specific and not universally supported. Verify with the specific MAC or commercial payer policy before billing separately. Do not append modifier 59 automatically — document distinct operative site if reported.

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❌ Excludes / Do Not Report With (per NCCI and CPT Guidelines)

Code	Description	Reason
21431	LeFort III, without IF	Lower-tier; mutually exclusive
21432	LeFort III, with IF	Lower-tier; mutually exclusive
21433	Complicated, no IF	Lower-tier; mutually exclusive
21434	Complicated, with graft	Lower-tier; mutually exclusive
21435	Complicated, with IF	Lower-tier; mutually exclusive
20900	Bone graft, minor	Bundled unless distant site (payer-specific)
20902	Bone graft, major	Bundled unless distant site (payer-specific)

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🔧 Modifiers

Modifier	Name	When to Use with 21436
-22	Increased Procedural Services	Significantly prolonged operative time; extreme comminution; revision of failed prior repair; must attach documentation
-51	Multiple Procedures	When 21436 is not the primary procedure — apply to the secondary code(s)
-59	Distinct Procedural Service	If a separately reportable bone graft from a distant donor site is billed on the same claim
-62	Two Surgeons	When Oral/Maxillofacial Surgery and Neurosurgery (or Plastic Surgery) simultaneously perform distinct portions of the procedure; each surgeon bills 21436-62
-66	Team Surgery	When 3 or more surgeons are concurrently required (rare; requires payer pre-authorization)
-80	Assistant Surgeon	Licensed physician assistant at surgery
-82	Assistant Surgeon (no resident available)	Teaching hospital without available qualified resident
-AS	Non-Physician Practitioner (PA/NP/CNS)	Non-physician assistant at surgery; typically 85% of -80 rate
-78	Unplanned Return to OR	Unplanned reoperation for related complication within global period
-79	Unrelated Procedure in Global Period	Separate unrelated surgery during the 90-day global
-XS	Separate Structure (NCCI X-modifier)	May substitute for -59 for CMS claims; distinct body structure

Modifier -62 Is Common Here

Complex Le Fort III repairs are frequently performed as a co-surgery between a craniofacial/oral & maxillofacial surgeon and a neurosurgeon, particularly when skull base involvement requires intracranial exposure or dural repair. Both surgeons bill 21436--62. Each surgeon’s operative note must clearly document their individual, distinct contributions.

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🩺 Commonly Associated ICD-10-CM Diagnosis Codes

HCC Applicability

None of the primary diagnosis codes associated with 21436 are mapped to CMS HCC (Hierarchical Condition Category) risk adjustment categories under the current CMS-HCC v28 model. HCC mapping is irrelevant for these specific diagnoses and is noted as Not HCC below.

Traumatic Indications

ICD-10-CM	Description	HCC
S02.413A	Le Fort III fracture, bilateral, initial encounter	Not HCC
S02.411A	Le Fort III fracture, right side, initial encounter	Not HCC
S02.412A	Le Fort III fracture, left side, initial encounter	Not HCC
S02.19XA	Other fracture of base of skull, initial encounter	Not HCC
S02.0XXA	Fracture of vault of skull, initial encounter, closed	Not HCC

Congenital / Syndromic Indications

ICD-10-CM	Description	HCC
Q75.1	Craniofacial dysostosis (Crouzon syndrome)	Not HCC
Q75.0	Craniosynostosis	Not HCC
Q75.4	Mandibulofacial dysostosis (Treacher Collins syndrome)	Not HCC
Q75.8	Other specified congenital malformations of skull and face bones	Not HCC
Q87.0	Congenital malformation syndromes predominantly affecting facial appearance (includes Apert syndrome)	Not HCC

Acquired / Other Indications

ICD-10-CM	Description	HCC
M85.08	Fibrous dysplasia (monostotic), other site	Not HCC
M95.2	Other acquired deformity of head	Not HCC

Sequencing Tip

For traumatic cases, the fracture code (S02.411A-S02.413A) is the principal diagnosis. Sequence concomitant injuries (e.g., orbital fractures, skull base fractures, CSF leak) as additional diagnoses. For congenital/syndromic cases, the syndrome or anomaly code is principal.

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🏥 ICD-10-PCS Equivalents (Inpatient Coding)

Inpatient Coding Note

In the inpatient setting, CPT codes are not used for facility billing. Coders assign ICD-10-PCS procedure codes. The following PCS codes are commonly applicable to the procedure described by CPT 21436.

Core PCS Codes

ICD-10-PCS	Description	Key Characters
0NSW04Z	Reposition Facial Bone with Internal Fixation Device, Open	S=Reposition, W=Facial Bone, 0=Open, 4=Internal Fixation Device
0NUW07Z	Supplement Facial Bone with Autologous Tissue Substitute, Open	U=Supplement, W=Facial Bone, 7=Autologous (bone graft)
0NUW0KZ	Supplement Facial Bone with Nonautologous Tissue Substitute, Open	U=Supplement, W=Facial Bone, K=Nonautologous

If Skull Base / Cranial Approach Is Also Coded

ICD-10-PCS	Description
0NSC04Z	Reposition Sphenoid Bone with Internal Fixation Device, Open
0NSR04Z	Reposition Maxilla with Internal Fixation Device, Open
0NSN04Z	Reposition Zygomatic Bone, Left with Internal Fixation Device, Open
0NSM04Z	Reposition Zygomatic Bone, Right with Internal Fixation Device, Open

PCS Body Part Selection

Use W (Facial Bone) as the body part character when the procedure addresses multiple facial bones simultaneously as a single unified operation. PCS Guideline B4.3 — the body part coded reflects the site of the procedure, not incidentally affected structures. When the entire midfacial skeleton is mobilized as one unit (Le Fort III), reporting a single code with body part W is appropriate unless distinct, separate root operations are performed on individual bones._{ICD-10-PCS Official Guidelines 2026}

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🏨 MS-DRG Assignment

MS-DRG Tip for Inpatient Coders

MS-DRG assignment in the inpatient setting is driven by ICD-10-PCS procedure codes and ICD-10-CM principal diagnosis — not CPT. The DRGs below reflect typical grouping scenarios for cases where this procedure is performed.

Primary MS-DRG Pathway — MDC 03 (Ear, Nose, Mouth & Throat)

When 0NSW04Z or 0NUW07Z is assigned as the principal procedure and the principal diagnosis is a facial bone fracture or congenital craniofacial anomaly (Q75.x, S02.4xx):

MS-DRG	Description	CC/MCC
133	Other Ear, Nose, Mouth and Throat O.R. Procedures	w MCC
134	Other Ear, Nose, Mouth and Throat O.R. Procedures	w CC
135	Other Ear, Nose, Mouth and Throat O.R. Procedures	w/o CC/MCC

Alternate MS-DRG Pathway — MDC 01 (Nervous System)

When neurosurgery is the principal procedure (e.g., intracranial approach, dural repair) and craniofacial repair is secondary:

MS-DRG	Description	CC/MCC
025	Craniotomy & Endovascular Intracranial Procedures	w MCC
026	Craniotomy & Endovascular Intracranial Procedures	w CC
027	Craniotomy & Endovascular Intracranial Procedures	w/o CC/MCC

DRG Optimization

Accurate capture of MCC conditions (e.g., CSF leak G96.01, pneumocephalus G93.89, septicemia, respiratory failure) significantly affects DRG severity and reimbursement. Coders should query providers for documentation of these complications when present in the medical record.

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🔗 Commonly Co-Reported CPT Codes

CPT	Description	Notes
21346	Open treatment NOE complex fracture, internal fixation	Frequently co-existing injury; may be separately reportable
21390	Open treatment orbital floor fracture with implant	If orbital floor is separately addressed
21440	Closed treatment Le Fort I fracture, w/o interdental fixation	Lower-level fracture at same encounter — lower complexity
20902	Bone graft, any donor area — major/large	Report only if distant donor site is used (see Includes note)
20900	Bone graft, any donor area — minor/small	Same caveat as 20902
21230	Rib cartilage graft, autogenous, to face/nose	If rib is separate graft donor
21299	Unlisted craniofacial procedure	If concomitant unlisted reconstruction performed
61580	Craniofacial approach to anterior cranial fossa — extradural	Skull base approach by neurosurgery
61582	Craniofacial approach — epidural	Neurosurgery co-surgery approach
69990	Microsurgical techniques — add-on	If performed under microscopy
99100	Anesthesia qualifier — extreme age	If patient ≤1 year or ≥70 years

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⚠️ Coding Traps & Clinical Tips

Trap 1 — Graft Harvest Is Bundled

Do not separately bill 20902 when bone graft is harvested from the same operative field or a standard cranial donor site. The descriptor explicitly states “includes obtaining graft.” Separate billing of graft harvest without documentation of a distinct, distant donor site risks claim denial and audit flags.

Trap 2 — "Complicated" Must Be Documented

Upgrading from 21431/21432 to 21433-21436 requires explicit documentation of skull base involvement, comminution, or multiple osteotomy levels. A coder cannot assume “complicated” based on operative time alone. Query the provider if ambiguous.

Trap 3 — Do Not Unbundle the Le Fort Series

Each code in the 21431-21436 family is mutually exclusive. Report only the single code that represents the highest complexity tier actually performed. Do not stack 21432 + 21433 for the same craniofacial separation.

Tip — Modifier -62 Documentation

When modifier -62 is applied, both operative notes (neurosurgery and craniofacial/OMFS) must document distinct contributions. A single operative note signed by both surgeons is not sufficient for most MACs.

Tip — Congenital vs. Traumatic

This code applies to both traumatic fracture repair and elective craniofacial reconstruction for congenital anomalies (Crouzon, Apert, etc.). The clinical context determines the diagnosis code, but the procedure code 21436 is appropriate for either scenario when complexity criteria are met.

Tip — 2025 Descriptor Change

The CPT descriptor was updated January 1, 2025. If referencing older fee schedules or payer contracts tied to the prior descriptor, verify alignment with current AMA CPT text.

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📝 Coding Examples

Example 1 — Traumatic Le Fort III, Bilateral, Co-Surgery

Clinical Scenario: A 28-year-old male presents after a high-speed motor vehicle accident with bilateral Le Fort III fracture with associated naso-orbito-ethmoid disruption, comminution at the pterygoid plates, and an anterior skull base fracture with confirmed CSF rhinorrhea. Neurosurgery performs an intracranial approach for dural repair; the craniofacial team simultaneously performs the midface reduction via coronal and transoral approaches, applying titanium miniplates and harvesting outer table cranial bone graft to reconstruct the nasomaxillary buttress.

CPT (Professional/Physician):

• 21436--62 (Craniofacial surgeon)
• 21436--62 (Neurosurgeon — co-surgeon)
• 61582 (Craniofacial approach, epidural — billed by neurosurgery separately if documented as distinct component)

ICD-10-CM:

• S02.413A — Le Fort III fracture, bilateral, initial encounter (principal)
• S06.300A — Unspecified focal traumatic brain injury, initial encounter
• G96.01 — Intracranial hypotension, spontaneous (or CSF leak if documented)
• External cause codes as appropriate

ICD-10-PCS (Inpatient Facility):

• 0NSW04Z — Reposition Facial Bone with Internal Fixation Device, Open
• 0NUW07Z — Supplement Facial Bone with Autologous Tissue Substitute, Open
• 00N10ZZ — Release Dura Mater, Open (if dural repair)

MS-DRG: If neurosurgery PCS code principal → MS-DRG 025 (Craniotomy w MCC — given CSF leak)

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Example 2 — Crouzon Syndrome, Elective Le Fort III Advancement

Clinical Scenario: A 14-year-old female with known Crouzon syndrome (Q75.1) presents for elective midfacial advancement. The craniofacial surgeon performs a Le Fort III-level osteotomy with simultaneous Le Fort I osteotomy for differential movement, with iliac crest bone graft harvested through a separate incision and titanium plate fixation. Due to the additional Le Fort I osteotomy, the case is documented as “complicated with multiple osteotomy levels.”

CPT (Professional):

• 21436--22 (Modifier -22 may be appropriate given the added Le Fort I osteotomy performed at the same setting; attach documentation)
• 20902 (Bone graft, iliac crest — distant donor site, separately reportable)

ICD-10-CM:

• Q75.1 — Craniofacial dysostosis (principal)
• M95.2 — Other acquired deformity of head (secondary, if applicable)

ICD-10-PCS (Inpatient Facility):

• 0NSW04Z — Reposition Facial Bone with Internal Fixation Device, Open
• 0NSR04Z — Reposition Maxilla with Internal Fixation Device, Open (for Le Fort I component)
• 0NUW07Z — Supplement Facial Bone with Autologous Tissue Substitute, Open

MS-DRG: → MS-DRG 134 or 135 (Other ENT O.R. Procedure, CC/MCC status dependent on comorbidities)

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Example 3 — Failed Prior Repair, Revision Le Fort III

Clinical Scenario: A 35-year-old female with post-traumatic craniofacial deformity following a prior Le Fort III repair 2 years ago presents for revision surgery. The operative note documents removal of prior hardware, multiple osteotomies, rib graft harvest, and titanium reconstruction plate fixation.

CPT (Professional):

• 21436--22 (Revision adds substantial additional work; -22 appropriate with supporting documentation)
• 21230 (Rib cartilage graft, if rib cartilage was specifically used for nasal/ear reconstruction)
• 20902 (Rib bone graft if cortical/cancellous bone from separate rib incision)

ICD-10-CM:

• M95.2 — Other acquired deformity of head (principal)
• History codes as appropriate

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📚 Sources

_{AMA CPT Professional Edition 2025 · CMS Medicare Physician Fee Schedule (MPFS) RVU File · ICD-10-PCS Official Guidelines for Coding & Reporting FY2026 · ICD-10-CM Official Guidelines FY2026 · StatPearls — Le Fort Fractures (updated Dec 2024) · StatPearls — Le Fort Osteotomy (updated Aug 2024) · CMS ICD-10-PCS/MS-DRG v41.0 Definitions Manual · CMS NCCI Policy Manual 2025}