CPT code 33427 represents mitral valvuloplasty performed with cardiopulmonary bypass — a complex open-heart surgical repair of the mitral valve and subvalvular apparatus. Nationally, this code captures procedures intended to correct mitral stenosis, subvalvular fibrosis, and annular dilatation-related insufficiency, including intraoperative ring or band placement when indicated. The procedure is clinically significant due to its role in preserving native valve function, reducing the need for prosthetic replacement, and affecting perioperative resource use and outcomes.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context, typical site of service, and the service type associated with the code. The publication also outlines commonly applied modifiers and governance-relevant considerations for coding and billing workflows. Policy and benchmarking content highlights how this code is treated across major national payers and in Medicare coverage frameworks, offering readers a clear picture of reimbursement posture, utilization considerations, and documentation expectations tied to mitral valve repair with cardiopulmonary bypass.

This executive summary is intended for clinical coders, revenue cycle professionals, and policy analysts looking for a national-level briefing on coding, billing, and clinical implications for CPT code 33427.