Summary & Overview

CPT 21423: Complex Maxillary Fracture Open Reduction and Internal Fixation

CPT code 21423 represents an open reduction and internal fixation procedure for a complicated fracture of the maxilla (roof of the mouth or upper jaw bone). This surgical code is used when multiple incisions or approaches are required to expose and stabilize comminuted or displaced fractures of the upper jaw. Nationally, accurate use of this code matters for clinical documentation, hospital resource planning, and appropriate surgical reimbursement for high-acuity facial trauma.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for when CPT code 21423 is appropriate, plus benchmarks and coding considerations relevant to facility and surgeon billing. The publication summarizes typical sites of service, common modifiers used in practice, and related billing themes for complex maxillofacial trauma care.

This resource is intended to inform coding professionals, clinicians, and revenue managers about the clinical scenario tied to CPT code 21423, common payer coverage considerations, and what to review in claim documentation to support medical necessity. Data not available in the input are listed where applicable in detailed sections.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare21423CPTmaxillofacial surgeryopen reductioninternal fixationfacial traumasurgical codingoperating room

Billing Code Overview

CPT code 21423 describes surgical treatment for a complicated fracture of the maxilla (roof of the mouth or upper jaw bone), typically resulting from blunt force trauma. The procedure involves open reduction and internal fixation using incisions in multiple areas to access and stabilize the fracture.

Service type: Surgical repair (open reduction and internal fixation) for complex maxillofacial fracture
Typical site of service: Hospital operating room or ambulatory surgical center

Clinical & Coding Specifications

Clinical Context

A 34-year-old male presents to the emergency department after an assault with blunt facial trauma. He reports severe facial pain, malocclusion, nasal bleeding, and numbness of the upper lip. Imaging (CT maxillofacial) demonstrates a comminuted fracture of the maxillary alveolar process and roof of the maxilla with displacement and involvement of the maxillary sinus walls. The oral and maxillofacial surgery team evaluates the patient, documents the fracture pattern, neurovascular status, and dental involvement, and obtains informed consent for open reduction and internal fixation under general anesthesia. The operating room workflow includes preoperative antibiotics, intraoral and possibly external vestibular incisions, reduction of bony segments, fixation with plates and screws, sinus repair as needed, hemostasis, and layered closure. Postoperative care includes pain control, antibiotics, soft diet instructions, wound checks, and follow-up imaging to confirm reduction and hardware position. Hospital inpatient admission may be necessary for airway monitoring, swelling control, or associated injuries. Typical site of service is an operating room in a hospital or an ambulatory surgery center for non-emergent stable patients. Service type: surgical open reduction and internal fixation of complicated maxillary fractures.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work, time, or complexity substantially exceeds typical for the procedure due to severe comminution, multiple approaches, or extensive reconstruction.
`23`	Unusual anesthesia	Use when procedure is performed under general anesthesia solely because of severity or patient condition and local/regional anesthesia is contraindicated.
`26`	Professional component	Use when reporting only the surgeon's professional portion separate from technical facility charges (rare for surgical CPTs billed by hospitals).
`50`	Bilateral procedure	Use if identical maxillary procedures are performed bilaterally and payer requires bilateral modifier reporting.
`51`	Multiple procedures	Use when multiple distinct procedures are performed in the same session in addition to the primary procedure.
`52`	Reduced services	Use when the procedure is partially reduced or not completed as originally planned.
`53`	Discontinued procedure	Use when the procedure is terminated for patient safety before completion.
`58`	Staged or related procedure or service by the same physician during the postoperative period	Use when a planned subsequent procedure is performed during the global period as part of staged reconstruction.
`62`	Two surgeons	Use when two surgeons from different specialties perform distinct portions of the procedure, e.g., ENT and oral/maxillofacial surgeons.
`78`	Unplanned return to the operating room for a related procedure during the postoperative period	Use when the patient returns to OR emergently for complication management related to this procedure.
`79`	Unrelated procedure or service by the same physician during the postoperative period	Use when an unrelated surgery is performed during the global period.
`80`	Assistant surgeon	Use when a qualified assistant surgeon participates in the case and the payer requires reporting of assistant services.
`81`	Minimum assistant surgeon	Use when minimal assistance is provided and payer recognizes this modifier.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery	Use when an eligible mid-level practitioner serves as the assistant during surgery.

Taxonomy Code	Specialty	Notes
`103K00000X`	Oral and Maxillofacial Surgery	Primary specialty performing complex maxillary fracture ORIF and management of dentoalveolar involvement.
`207L00000X`	Otolaryngology (ENT)	Frequently involved when sinuses, nasal framework, or facial skeleton require ENT expertise.
`2080P0208X`	Plastic and Reconstructive Surgery	Consulted for complex soft-tissue or facial reconstructive needs.
`163WL0500X`	General Surgery (Trauma Surgeon)	In trauma centers, trauma surgeons coordinate care for multi-system injured patients; may assist with facial fractures.
`2086S0122X`	Oral and Maxillofacial Surgery - Hospitalist/Academic	Providers in hospital-based practice performing operative fixation in admitted patients.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`S02.4XXA`	Fracture of malar and maxillary bones, initial encounter	Directly describes maxillary complex fractures requiring ORIF.
`S02.2XXA`	Fracture of nasal bones, initial encounter	Nasal fractures commonly accompany maxillary trauma and may require concurrent management.
`S02.6XXA`	Fracture of orbit, initial encounter	Orbital involvement often occurs with maxillary fractures and may need coordinated repair.
`S02.3XXA`	Fracture of zygomatic arch, initial encounter	Zygomatic complex injuries can be present with maxillary roof fractures and affect surgical approach.
`T79.A11A`	Traumatic arthropathy of jaw, initial encounter	May be used when temporomandibular joint injury or dysfunction occurs with facial fractures.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`21423`	Open treatment of complicated fracture(s) of the maxilla, multiple approaches, with internal fixation	Primary procedure: open reduction and internal fixation of complicated maxillary fractures.
`21077`	Excision or drainage of infected maxillary sinus with incision and drainage	Performed if sinus infection or empyema is encountered during fracture management.
`21345`	Open treatment of mandibular fracture, complex, with internal fixation	May be performed in the same operative session when concomitant mandibular fractures are present.
`70100`	CT scan of the facial bones without contrast	Preoperative imaging commonly obtained to define fracture pattern and plan fixation.
`31575`	Intubation, endotracheal, emergency or routine for general anesthesia	Supports airway management for general anesthesia during operative fixation.
`99024`	Postoperative follow-up visit global period (hospital)	Represents postoperative inpatient follow-up care; facility or provider reporting varies by payer.