CPT code 33904 is an add-on code for endovascular stent placement in the pulmonary arteries, reported when one or more additional stents are deployed beyond the primary vessel or lesion during the same encounter. This code captures incremental procedural work and device-based intervention for pulmonary artery stenosis or related vascular lesions and is relevant for facilities and clinicians billing complex interventional cardiothoracic and interventional radiology services. Nationally, accurate use of this code affects case mix reporting, reimbursement bundling, and quality measurement for pulmonary vascular interventions.

Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find: a concise explanation of the clinical and billing intent of the code; typical settings where the service is delivered; common modifiers associated with procedural reporting (input provided); and guidance on where data were not available in the input. The publication outlines benchmarks and payment-policy considerations where available, clarifies the code’s role as an add-on service, and provides clinical context for when additional stents would be reported. Data not available in the input are explicitly noted for items such as associated taxonomies, ICD-10 diagnoses, related codes, and payer-specific fee schedules.