ASTRO submitted an official comment letter September 16 on Medicare’s proposal to require more than 1,000 radiation oncology practices to participate in a new alternative payment model. The comments outline significant flaws and recommended reforms that must be made before the Centers for Medicare and Medicaid Services (CMS) finalizes the Radiation Oncology Model (RO Model) this Fall and implements the changes as early as January 1, 2020. ASTRO’s comments address mandatory participation, excessive payment cuts, and unnecessary administrative burden among other concerns with the model. ASTRO will continue advocacy on multiple fronts to improve the model.