95018 drug allergy testing

I billed 99213-25, 3 units 95017, 20 units 95018. I am not getting paid for the 95018. The practice is in Illinois, NGS is our processor for Medicare. My denial remark is frequency, and number exceeds max. Yet I cannot find any documentation for limiting units amt for this code submission to Medicare. Any ideas?

re: 95018 drug allergy testing

You can only bill up to 19 units for that code. You can find the MUE on cms.gov website. Put in excel spreadsheet and use it for the future..