CPT code 33946 denotes initiation of venovenous extracorporeal circulation — the placement of a venous cannula to drain and return blood within the venous system to provide respiratory support. This procedure is used when conventional ventilation is insufficient, including severe acute respiratory distress syndrome (ARDS), cardiopulmonary insufficiency with predominant respiratory failure, or as a bridge to lung transplantation. Nationally, the code is important for documenting advanced respiratory support and resource-intensive critical care interventions.

Key payers in the coverage landscape include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context for use of the code, typical settings of care and service type, and operational details relevant to billing. The publication outlines benchmarks and payer policy patterns where available, summarizes coding considerations tied to service lines and sites of service, and highlights recent policy activity and clinical developments that affect documentation and billing for advanced extracorporeal support.

The report is intended for clinicians, coding professionals, and policy analysts seeking a concise reference on CPT code 33946, its clinical role, and implications for billing and coverage in high-acuity respiratory care.