@danab

I think the "cancer doctor" is called an oncologist. My husband will be seeing a UCLA hematologist/oncologist who's office is local and there is an UCLA infusion center in the same medical building so that's a good thing. I'll be sure to ask about insurance coverage re IVIG at hematologist consultation.
My husband had Medicare(and employer insurance) at time of his kidney transplant but no longer qualifies after 3 year post transplant. I remember the Mayo Az transplant coordinator telling me that with Medicare it's always easier/faster to get prior authorization than other insurance with respect to IVIG infusion work. Hubby continues to work full time so we have Anthem Blue Cross PPO and fortunately Mayo Clinic is in-network in our plan.