CPT code 33259 denotes an extensive surgical ablation and reconstruction of the left and right atria performed at the same time as another cardiac procedure, with the patient on cardiopulmonary bypass. This code captures high-complexity, inpatient cardiothoracic surgery aimed at treating atrial fibrillation by destroying arrhythmogenic atrial tissue and reconstructing atrial chambers. Nationally, the code is relevant for hospitals, cardiothoracic surgeons, and payers managing high-acuity cardiac surgical case mixes and episode-of-care payments.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication outlines clinical context for the procedure, expected service line and site of service, and payer coverage considerations. Readers will find a concise explanation of the procedure captured by CPT code 33259, commonly used claim modifiers and how they relate to complex cardiac surgery (listed elsewhere), and a summary of typical reimbursement and utilization benchmarks where available. The content is intended to help coding staff, billing managers, and policy analysts understand the clinical intent and billing context for this high-complexity cardiac surgical code at a national level.