Q: When patients have a true Medicare secondary insurance we've always billed other Medicare non-covered codes such as G0283 for electric stimulation with modifier GY because we are aware Medicare will not pay for that service but the secondary insurance does. We just were notified by our MAC that GY is not a valid modifier and I have to enter a GP or other therapy modifier. What is the new proper modifier to enter?
 
A: Medicare recently released an article stating that in order to track physical therapy caps, one of three therapy modifiers (i.e., GN, GO, or GP) needs to be added to the code on the claim. There are some MACs which have required modifier GP in this situation. All of the following codes are on that list:
97012, 97016, 97018, 97022, 97024, 97026, 97028, 97032, 97033, 97034, 97035, 97036, 97039, 97110, 97112, 97113, 97116, 97124, 97139, 97140, 97150, 97530, 97533, 97535, 97537, 97542, 97750, 97755, 97760, 97761, 97762 (this code was deleted and replaced by 97763 for 2018), 97799, G0281, G0283
Your MAC likely updated their claim editing to to reflect this update and are now requiring this modifier since of the three modifiers, GP is the most appropriate in a chiropractic setting. Click here to review the Medicare article.