ICD 10 B96.89

[JillG186]

ICD10 book states this is a supplemental code and cant be used as a primary code. We have billed with this code before and never got denials.  I received denials from United Healthcare. My provider doesnt understand that I need the dx code for the infectious agent.  He gave me pseudomonas, pyoderma,which still falls within the B96 range.  Help!  what can I tell provider? I am not a certified coder so am flying by the seat of my pants, LOL. TIA