CPT code 36405 identifies percutaneous venipuncture of a scalp vein in patients under three years of age for blood collection or medication administration. This pediatric vascular access code matters nationally because it captures a specialized procedure used in neonatal and infant care where peripheral limb access may be limited; appropriate coding affects clinical documentation, claims processing, and pediatric care workflows. Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for scalp vein access in young children, common payer coverage considerations, and what elements typically appear in claims lines for this service. The publication also outlines available benchmarks and policy-relevant notes where data exists and flags areas where information is not provided. Data not available in the input is explicitly noted. The goal is to equip coding professionals, pediatric clinicians, and billing managers with a clear, national-level reference for recognizing and documenting CPT code 36405 in relevant care settings.