The Registry Partners March 2020 CTR Coding Break discusses Radiation. Coding for radiation treatment has changed significantly for cases beginning with a diagnosis date of 01/01/2018 to provide NCDB with a more complete and accurate description of contemporary radiation treatment. The following is a brief description with several examples taken directly from the CTR Guide to Coding Radiation Therapy Treatment v2.0, February 2020. The NCDB clarification for coding I-131 is addressed along with the radiation treatment volume code of 86 Pelvis (NOS, non-visceral). Phase terminology is explained replacing the terms regional and boost. The total dose is further clarified reinforcing doses should only be summed across phases to create a Total dose when all phases were delivered sequentially not simultaneously. Finally, phase dose and total dose are clarified for any treatment modality coded between 07 and 16 which consists of brachytherapy, radioisotopes, and infusion therapy. An explanation is provided when the dose should be coded in cGy or coded to 999998.