Does cpt code 99396 require a 59 modifier?
Modifier 59 is used to represent a different session or patient encounter, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same physician. You would not use modifier 59 on an E&M service such as 99396.