This bill, known as the Radiology Outpatient Ordering Transmission (ROOT) Act, amends Title XVIII of the Social Security Act to revise data collection and compliance requirements for appropriate use criteria (AUC) related to applicable imaging services under Medicare. Beginning January 1, 2026, it mandates that qualified clinical decision support mechanisms (CDSMs) directly transmit specific patient and order information to the Secretary. This change aims to streamline the reporting process and enhance oversight of imaging service utilization. The legislation introduces several new exemptions from AUC requirements, including imaging services ordered as part of clinical trials and those ordered by professionals in small practices (15 or fewer ordering professionals) or practices located in rural health professional shortage areas. Additionally, specific preventive and screening services such as mammography , CT lung cancer screenings, and CT colonographies are now exempt. Furnishing professionals will also be required to include the ordering professional's National Provider Identifier (NPI) on claims for applicable imaging services. The bill redefines "outlier" ordering professionals as "low compliant" and directs the Secretary to annually determine these professionals based on their compliance rates, which measure adherence to CDSM consultation requirements. The Secretary must conduct regular studies, starting by January 1, 2031, to assess compliance rates, the impact on imaging utilization, and propose mechanisms for improvement, such as prior authorization for low compliant professionals. The bill also requires adherence to existing regulatory approaches for specifying AUC and CDSMs.