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CPT 21299: Craniofacial and Maxillofacial Unlisted Procedure

CPT code 21299 is an unlisted procedure code for craniofacial and maxillofacial surgeries that lack a specific CPT descriptor. It matters nationally because it is the default billing mechanism for novel, complex, or uncommon facial and cranial procedures where no precise code exists, affecting how payers adjudicate claims and determine medical necessity. Use of an unlisted code often triggers additional documentation and manual review, influencing reimbursement timelines and administrative workload.

Key payers in the national context include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical contexts where 21299 is used, how payers commonly handle unlisted craniofacial/maxillofacial claims, and practical benchmarking topics such as authorization and documentation expectations. The publication also addresses coding alternatives and related coding considerations where applicable.

This summary provides clinicians, coders, and billing managers with concise guidance on the purpose of 21299, expected sites of service, and what to expect in payer interactions. Data not available in the input is noted where applicable.

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Billing Code Overview

CPT code 21299 is an unlisted procedure code used to report craniofacial and maxillofacial procedures that do not have a specific code. This code captures a range of surgical services performed on the bones and soft tissues of the face and skull when no designated CPT code exists for the exact procedure.

Service Type: Craniofacial and maxillofacial surgery

Typical Site of Service: Hospital operating room, ambulatory surgical center, or specialized surgical clinic

Data not available in the input.

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CPT 21299: Craniofacial and Maxillofacial Unlisted Procedure

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Billing Code Overview

Service Type: Craniofacial and maxillofacial surgery

Typical Site of Service: Hospital operating room, ambulatory surgical center, or specialized surgical clinic

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A typical patient is an adult or adolescent presenting with a complex craniofacial or maxillofacial condition that does not fit an existing specific CPT code. Example scenarios include repair of an uncommon congenital craniofacial deformity, reconstruction after high-energy facial trauma with atypical combinations of fractures and soft-tissue loss, or bespoke recontouring procedures following tumor resection in the facial skeleton. The clinical workflow begins with evaluation by a craniofacial or maxillofacial surgical team in an outpatient or inpatient setting. Preoperative planning includes imaging (CT facial bones with 3D reconstruction), multidisciplinary consultation (plastic surgery, oral and maxillofacial surgery, otolaryngology, neurosurgery as needed), informed consent describing the atypical nature of the procedure, and documentation of the medical necessity for an unlisted code. On the day of service the patient undergoes general anesthesia in an operating room or ambulatory surgery center, the unlisted craniofacial/maxillofacial procedure is performed, intraoperative findings and unique technical components are documented, and operative time and personnel are recorded. Postoperative care includes routine recovery or inpatient observation depending on complexity, with detailed operative report supplied to payors to support claims adjudication for 21299.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	When the work, time, or complexity substantially exceeds the typical service for related procedures and documentation supports the increased work.
`50`	Bilateral procedure	When a bilateral craniofacial or maxillofacial procedure is performed and bilateral billing rules apply.
`52`	Reduced services	When the procedure performed is a reduced or partial service compared to the typical full procedure.
`53`	Discontinued procedure	When the procedure is started but discontinued due to extenuating circumstances documented in the record.
`59`	Distinct procedural service	When a separate and distinct procedure is performed on the same day at a different anatomic site or session.
`62`	Two surgeons	When two surgeons from different specialties are required to perform distinct portions of the case and both document their separate work.
`66`	Surgical team	When the procedure requires a team approach with documented roles for each team member.
`76`	Repeat procedure by same physician	When the same procedure is repeated at the request of the same physician within the global period (Note: `76` is not in the provided list; it is not used here.)
`78`	Unplanned return to the OR following initial procedure	When the patient returns to the operating room for a related procedure during the postoperative period.
`80`	Assistant surgeon	When an assistant surgeon participates and meets payer-specific assistant surgeon criteria.
`81`	Minimum assistant surgeon	When a minimum assistant is used per facility/payer rules.
`82`	Assistant surgeon (when qualified resident not available)	When a qualified resident is not available and an assistant is required.
`26`	Professional component	When reporting only the professional portion of a service if applicable (limited applicability to procedures but used for associated professional interpretations).
`73`	Discontinued outpatient hospital/ASC procedure prior to anesthesia	When an outpatient procedure is cancelled after patient preparation but before anesthesia is administered.
`59`	Distinct procedural service	(Included above; avoid duplication)

Taxonomy Code	Specialty	Notes
207P00000X	Plastic and Reconstructive Surgery	Commonly performs craniofacial reconstruction and complex soft-tissue procedures.
1223P0002X	Oral and Maxillofacial Surgery	Performs bony reconstruction, fracture fixation, and orthognathic interventions.
2080P0225X	Otolaryngology (Head and Neck Surgery)	Manages complex facial trauma, tumor resection involving airway and paranasal sinuses.
207L00000X	Neurological Surgery	Involvement when cranial vault or intracranial reconstruction is required.
310400000X	Surgical Oncology (Head & Neck)	Engaged for tumor extirpation and reconstructive planning.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`S02.4XXA`	Fracture of malar and maxillary bones, initial encounter	Midface fractures that may require atypical reconstructive or fixation techniques reported with `21299` when specific codes do not capture the work.
`S02.6XXA`	Fracture of mandible, initial encounter	Complex mandible fractures with unusual patterns or combined approaches may be reported with an unlisted craniofacial code.
`Q67.2`	Craniofacial dysostosis	Congenital craniofacial syndromes requiring bespoke surgical correction not described by specific CPT codes.
`C41.2`	Malignant neoplasm of mandible	Tumor resection with nonstandard reconstructive requirements may necessitate use of `21299`.
`T81.31XA`	Disruption of wound, initial encounter	Complicated wound management or revision reconstructions of the facial skeleton that lack a specific code.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`21120`	Reconstruction of mandible, partial, with bone graft (includes obtaining graft)	May be performed before or alongside an unlisted craniofacial procedure when bony reconstruction of the mandible is required.
`21248`	Reconstruction, zygoma, complex, with bone graft (includes obtaining graft)	Often used for specific zygomatic reconstruction; `21299` may be reported when the zygomatic reconstruction differs substantially from described procedures.
`21385`	Open treatment of malar and/or zygoma fractures with internal fixation	Commonly performed for facial fracture fixation; use alongside `21299` when additional atypical craniofacial techniques are required.
`15734`	Muscle, myocutaneous, or fasciocutaneous flap with microvascular anastomosis	Soft-tissue free flap reconstruction frequently accompanies complex craniofacial reconstruction and may be billed with `21299` for unlisted bony or contouring components.
`21086`	Reconstruction, mandible, contouring and augmentation (not including bone graft)	Used for contouring procedures; `21299` applies when the reconstructive technique is unique and not otherwise described.

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Clinical & Coding Specifications

Clinical Context

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	When the work, time, or complexity substantially exceeds the typical service for related procedures and documentation supports the increased work.
`50`	Bilateral procedure	When a bilateral craniofacial or maxillofacial procedure is performed and bilateral billing rules apply.
`52`	Reduced services	When the procedure performed is a reduced or partial service compared to the typical full procedure.
`53`	Discontinued procedure	When the procedure is started but discontinued due to extenuating circumstances documented in the record.
`59`	Distinct procedural service	When a separate and distinct procedure is performed on the same day at a different anatomic site or session.
`62`	Two surgeons	When two surgeons from different specialties are required to perform distinct portions of the case and both document their separate work.
`66`	Surgical team	When the procedure requires a team approach with documented roles for each team member.
`76`	Repeat procedure by same physician	When the same procedure is repeated at the request of the same physician within the global period (Note: `76` is not in the provided list; it is not used here.)
`78`	Unplanned return to the OR following initial procedure	When the patient returns to the operating room for a related procedure during the postoperative period.
`80`	Assistant surgeon	When an assistant surgeon participates and meets payer-specific assistant surgeon criteria.
`81`	Minimum assistant surgeon	When a minimum assistant is used per facility/payer rules.
`82`	Assistant surgeon (when qualified resident not available)	When a qualified resident is not available and an assistant is required.
`26`	Professional component	When reporting only the professional portion of a service if applicable (limited applicability to procedures but used for associated professional interpretations).
`73`	Discontinued outpatient hospital/ASC procedure prior to anesthesia	When an outpatient procedure is cancelled after patient preparation but before anesthesia is administered.
`59`	Distinct procedural service	(Included above; avoid duplication)

Taxonomy Code	Specialty	Notes
207P00000X	Plastic and Reconstructive Surgery	Commonly performs craniofacial reconstruction and complex soft-tissue procedures.
1223P0002X	Oral and Maxillofacial Surgery	Performs bony reconstruction, fracture fixation, and orthognathic interventions.
2080P0225X	Otolaryngology (Head and Neck Surgery)	Manages complex facial trauma, tumor resection involving airway and paranasal sinuses.
207L00000X	Neurological Surgery	Involvement when cranial vault or intracranial reconstruction is required.
310400000X	Surgical Oncology (Head & Neck)	Engaged for tumor extirpation and reconstructive planning.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`S02.4XXA`	Fracture of malar and maxillary bones, initial encounter	Midface fractures that may require atypical reconstructive or fixation techniques reported with `21299` when specific codes do not capture the work.
`S02.6XXA`	Fracture of mandible, initial encounter	Complex mandible fractures with unusual patterns or combined approaches may be reported with an unlisted craniofacial code.
`Q67.2`	Craniofacial dysostosis	Congenital craniofacial syndromes requiring bespoke surgical correction not described by specific CPT codes.
`C41.2`	Malignant neoplasm of mandible	Tumor resection with nonstandard reconstructive requirements may necessitate use of `21299`.
`T81.31XA`	Disruption of wound, initial encounter	Complicated wound management or revision reconstructions of the facial skeleton that lack a specific code.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`21120`	Reconstruction of mandible, partial, with bone graft (includes obtaining graft)	May be performed before or alongside an unlisted craniofacial procedure when bony reconstruction of the mandible is required.
`21248`	Reconstruction, zygoma, complex, with bone graft (includes obtaining graft)	Often used for specific zygomatic reconstruction; `21299` may be reported when the zygomatic reconstruction differs substantially from described procedures.
`21385`	Open treatment of malar and/or zygoma fractures with internal fixation	Commonly performed for facial fracture fixation; use alongside `21299` when additional atypical craniofacial techniques are required.
`15734`	Muscle, myocutaneous, or fasciocutaneous flap with microvascular anastomosis	Soft-tissue free flap reconstruction frequently accompanies complex craniofacial reconstruction and may be billed with `21299` for unlisted bony or contouring components.
`21086`	Reconstruction, mandible, contouring and augmentation (not including bone graft)	Used for contouring procedures; `21299` applies when the reconstructive technique is unique and not otherwise described.

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.