Background: After months of anticipation, CMS is planning to go forward with the mandatory Radiation Oncology Model. This bundled payment model, which was first announced in a proposed rule on July 10, 2019, with an anticipated start in January or April 2020, is notable for being one of the first mandatory models the industry has seen from CMS in years. While the model has been delayed, in part due to the complications presented by the COVID-19 public health emergency, CMS finally broke its silence on the future of the model in September with the publication of the RO model final rule. A revised start date was announced in the OPPS final rule in December: the RO model is anticipated to begin on July 1, 2021 and will run through 2025. Key facts: RO participants include freestanding radiation therapy centers, hospital outpatient departments and physician group practices with radiation oncologists that furnish radiation therapy services. The model is mandatory for selected participants.