Would you clarify the use of modifier KX for the fourth PET scan for subsequent treatment strategy? Are hospitals required to use this modifier, or is it just for physicians?


Both hospitals and physicians (and non-hospital imaging centers) need to add modifier KX (requirements specified in the medical policy have been met) to the fourth or greater subsequent treatment strategy PET scan claim. The modifier is used when the requirements for a fourth (or subsequent) PET scan for the same cancer have been met. For Medicare, the individual Medicare Administrative Contractor (MAC) will determine whether or not to pay for the service.


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