Ask Dr. Z

This seems like a simple code issue, but I continue to debate with myself over it. "(AVF) Forearm native radial artery cannulated retrograde beyond arterial anastomosis. Retrograde brachial angiogram done, which shows patent brachial ulnar, interosseous, and radial artery. Native radial proximal and distal forearm stenosed. Sheath repositioned and fistulogram done." What is the proper use of code 36120? I research code 36120 and it states retrograde brachial access, but the physician is accessing the radial artery retrograde. Is code 36120 only for retrobrachial, or can it be used for retroradial access as well? And would I code for retrobrachial angio 75658, as well as 75710 and 75791? Thank you in advance for your time and expertise.