CPT code 36218 is an add-on selective catheterization code for advancing a catheter into additional first-, second-, third- or smaller-order thoracic or brachiocephalic branch vessels to perform angiography. Nationally, the code captures incremental procedural work when clinicians perform more distal or additional branch catheterizations beyond the primary selective catheterization, affecting documentation, billing granularity, and payment adjudication for vascular diagnostic procedures.

Key payers included in the analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise overview of the clinical context for 36218, the typical settings where the service is provided, and the implications for coding and claims submission. The publication summarizes common billing considerations, lists frequently used modifiers, and outlines benchmarking and policy topics relevant to payers and providers.

This report provides actionable reference material for coding staff, clinical teams, and revenue professionals seeking clarity on when 36218 is reported in addition to a primary selective catheterization code, how sites of service commonly align with the procedure, and what to expect in payer coverage and claims processing at a national level.