The Centers for Medicare & Medicaid Services (CMS) has reissued guidance and billing instructions to Medicare Administrative Contractors (MACS) on its April adjustments to the National Coverage Determination for FDG-PET, set to take place later this month. <br / ><br / >Available on or after Oct. 19, providers will have two new modifiers to consider for initial treatment strategy or subsequent treatment strategy--by appending the modifiers PI or PS when submitting claims with a date of service on or after April 6 for the CPT codes for oncologic procedures: 78608 and 78811-78816. <br / ><br / >CMS described the modifiers as: <br / > <ul> <li>PI: PET or PET/CT to inform the initial treatment strategy of tumors that are biopsy proven or strongly suspected of being cancerous based on other diagnostic testing. </li> <li>PS: PET or PET/CT to inform the subsequent treatment strategy of cancerous tumors when the beneficiary's treating physician determines that the PET study is needed to inform subsequent anti-tumor strategy. </li> </ul> <br / >Until Oct. 19, CMS asks that claims continue to be submitted in accordance with past instructions. <br / ><br / >MACs have until Oct. 19 to implement these changes in their systems. PET facilities will likely have similar transition time, according to the American College of Radiology.