CPT code 21705 denotes open surgical division of the scalenus anticus muscle with removal of a cervical rib to relieve scalenus anticus syndrome, a neurovascular compression disorder of the neck. The code captures a targeted decompression procedure that can be definitive therapy for patients with symptomatic nerve or vascular impingement due to anatomic variants. Nationally, accurate coding for this procedure matters for surgical quality measurement, payer coverage determinations, and appropriate aggregation of utilization and outcome data.

Key payers referenced in the analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise clinical context for the procedure, typical sites of service (hospital operating rooms and ambulatory surgery centers), and the procedural intent (nerve/vascular decompression). Readers will find benchmarks and coding guidance, discussion of common billing modifiers and documentation touchpoints, and a summary of policy considerations that affect coverage and payment. Where specific data elements were not supplied, the text notes that data are not available in the input. This national overview supports clinicians, coders, and policy analysts seeking clear, code-level context for 21705 without state-specific details.