CPT code 21249 represents complex reconstructive surgery of the entire maxilla or mandible involving placement of a metallic implant into the jaw bone to restore form and function. Nationally, this code captures high-complexity maxillofacial reconstructive care used for large defects from trauma, tumor resection, or congenital anomalies and is relevant to hospital surgical services, oral and maxillofacial surgery departments, and payers managing high-cost surgical episodes. Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find clinical context for the procedure, typical sites of service, and the payer mix covered; benchmarks for utilization and reimbursement are not included in the input. The publication summarizes common billing considerations and operational settings for the service line, highlights where this code fits within maxillofacial surgical care, and identifies which payers are commonly involved in coverage and claims adjudication. Data not available in the input includes specific utilization metrics, payer-specific reimbursement rates, ICD-10 pairings, and associated taxonomies.