Is it being billed with any other services? Depending on what else it's being billed with, it could be hitting an NCCI edit.
88305 is a Column 2 code for a few CPTs and would need an NCCI-modifier (if applicable) to be reimbursed.
I'd also compare how many units are being billed to the MUEs. (In my experience, sometimes an MUE could show up as a modifier or other denials, because theoretically you could try billing a modifier to override the MUE. If there was sufficient documentation, of course.)