I have a new physician in the office and she does PSI (potassium sensitivity index) testing. This is new to me, I am a little unsure exactly how to bill it. She tells me her old office billed 51700, and 51701, and then J3480 for the supply code of the potassium chloride. Unfortunately my OB/GYN coding companion doesn't have the 51700 code in it so I am unsure if the 51701 is inclusive (my best guess is that it is). I am having a hard time finding the documentation to answer my question. Can anyone help?