Question: How should I code for use of an endoscope during a neurosurgical procedure? California Subscriber Answer: Use of an endoscope during neurosurgical procedures is rare, and CPT does not include a code to describe this technique as it does, for instance, for use of an operating microscope (+69990, Microsurgical techniques, requiring use of operating microscope [list separately in addition to code for primary procedure]). However, you may try to receive additional reimbursement by appending modifier -22 (Unusual procedural services) to the primary procedure code if the endoscope is medically necessary. For example, if performing a third ventriculocister-nostomy with the aid of an endoscope, report 62200-22. Be sure to include thorough documentation supporting your use of the modifier. Explain the circumstances of the surgery that required the endoscope, and estimate the amount of extra work. Based on this information, the payer will determine the amount of extra payment it will allow. Although use of the endoscope is an advanced technique, it does not necessarily add "work," "effort" or "time" to the basic procedure in fact, while it requires additional training and expertise, it may make the procedure easier than a more open procedure. The additional training may need to form the basis of any appeal for additional payment using modifier -22. Be aware that the payer may choose not to reimburse anything extra for use of the endoscope. Code 69990, for example, is incidental to many neurosurgical procedures and often is not reimbursed separately even when performed. Most payers are likely to view the endoscope in the same way.