I recently coded a pathology service with over 10 units of 88305. This was billed with all the units on 1 line. The carrier denied the entire amount stating 8 units is the limit and advised re billing with 8 units and adding modifier 91 on the next line with the remaining units. Has anyone used modifier 91 for the pathologist/professional component and what has your outcome been? Any thoughts, comments and suggestions would be appreciated!