Otolaryngology Coding Alert

Question: I am getting a denial for an add-on code, saying it was not billed with the correct primary code. Is there a list online of add-on codes with their corresponding primary codes? Louisiana Subscriber Answer: There is not a crosswalk for add-on codes. The CPT manual often lists the primary codes with which you are supposed to use the add-on code. For example, when you are looking to code +95920 (Intraoperative neurophysiology testing, per hour [List separately in addition to code for primary procedure]), it states directly beneath the code: "(Use 95920 in conjunction with the study performed, 92585, 95822, 95860, 95861, 95867, 95868, 95870, 95900, 95904, 95925-95937)." Similarly, for +69990 (Microsurgical techniques, requiring use of operating microscope [List separately in addition to code for primary procedure]), fewer codes are listed to go with the add-on code, but the CPT manual states: "The surgical microscope is employed when the surgical services are performed using the techniques of microsurgery. Code 69990 should be reported (without modifier 51 appended) in addition to the code for the primary procedure performed. Do not use 69990 for visualization with magnifying loupes or corrected vision." The CPT manual then lists numerous codes with which +69990 may not be used.