https://www.aapc.com/discuss/forums/pathology-clinical-laboratory.504/

Hi Victoria,

Thanks for your question.

When your lab uses an immunohistochemistry, you have to know when to report multiple units of CPT 88342. The following expert tips will help you get your 88342 coding right every time.

Tip 1: Heed the code definition and bill per antibody:- The 88342 description says, "each antibody," so you should report multiple units of the code if the lab performs more than one antibody stain on a single specimen. You should list each stain as one unit of...

https://www.aapc.com/discuss/forums/pathology-clinical-laboratory.504/