I have never thought about this before and have been working as a coder for many years, this came up today and I couldn't find a source of information for it. The question- when submitting a vaccine such as 90715 and medical necessity is not documented, we of course bill with the GZ modifier and it is a non-covered service, denied by Medicare, is it correct to submit the administration code such as 90471 without the GZ? In other words does Medicare allow payment for the administration of a non covered vaccine? I realize there is not a coverage policy for administration code 90471, however like I said I can't find policy on this. Appreciate any feedback.