Adding or Removing HCPCS Modifiers CT, FX, or GY

The Reopening’s process allows you to request corrections to minor errors or omissions on previously processed claims through myCGS, over the phone or in writing. Requests to add or remove HCPCS modifiers CT, FX, or GY cannot be handled over the phone, as they may require additional documentation and/or result in an overpayment.

CT — Computed tomography services furnished using equipment that does not meet each of the attributes of the Nat. Electrical Manuf. Association (NEMA) XR-29-2013 standard.

GY — Item or Service Statutorily Excluded or does not Meet the Definition of any Medicare Benefit

FX–     X-ray taken using film

Source: https://www.cgsmedicare.com/partb/pubs/news/2017/05/cope3005.html