On the hospital side, during an MAA mapping study, the doctors are using a device called a TriNav catheter to temporarily occlude the vessel. To be clear, they are not performing an embolization at this point. Historically, we have billed for catheterization and imaging, but with the release of the C9797 code, we are now being instructed to bill C9797 during the MAA mapping, even when no true embolization is performed. The patient returns a few weeks later for the Y90 treatment, which also involves the use of the TriNav catheter. At that time, I billed the procedure with C9797. What is the correct way to bill for the MAA mapping session on the hospital side?