CPT code 93588 covers catheter-based venous imaging performed during the same session as heart catheterization to identify and assess venovenous collaterals originating below the heart in patients with congenital cardiac defects. The code matters nationally because it documents a specific diagnostic technique used to clarify venous anatomy during invasive cardiac evaluation, which can influence subsequent interventions and care planning. Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, typical sites of service, and which payers are relevant to coverage discussions. The publication outlines expected billing practices, common modifiers submitted with the service, and how the code fits within cardiac interventional service lines. It also summarizes where to look for policy and coverage guidance, and highlights implications for claims processing and clinical documentation. Data not available in the input is noted where appropriate for areas such as associated taxonomies, ICD-10 diagnoses, and related codes.