CPT code 36406 identifies a pediatric venous access procedure involving needle insertion into a peripheral vein (excluding scalp, jugular, and carotid veins) for patients under three years of age. The code captures a focused clinical intervention commonly performed in emergency, inpatient, and outpatient pediatric settings and matters nationally because safe, timely vascular access in very young patients affects care delivery, procedural success rates, and resource use across health systems. Key payers in typical coverage analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. This publication provides a concise reference for clinical and billing staff about the code’s clinical context, typical sites of service, and where it fits within pediatric vascular access services. Readers will find benchmarks and coverage considerations where available, a description of common payment modifiers and coding relationships, and guidance on documentation elements relevant to reporting the service. Data not available in the input will be noted explicitly in applicable sections. The summary is intended for national audiences including clinicians, coding professionals, and policy analysts seeking a clear understanding of CPT code 36406 and its role in pediatric vascular access care.