This bill reauthorizes federal programs focused on traumatic brain injury (TBI) prevention, surveillance, and treatment support through fiscal years 2027 to 2031. It expands the Centers for Disease Control and Prevention's TBI surveillance program to better identify populations at higher risk, such as those affected by domestic violence, sexual assault, or certain occupations, and requires the agency to make aggregated TBI data publicly available online. The bill also updates state grant programs that fund TBI outreach, treatment, and protection and advocacy services, extending eligibility to Tribal organizations and refining the legal definition of traumatic brain injury. Additionally, it directs the Secretary of Health and Human Services to report to Congress within two years on efforts to reach high-risk populations and to conduct a study examining the long-term health effects of TBI, including links to dementia and mental health conditions. Overall, the legislation affects TBI survivors, public health agencies, state programs, and researchers by ensuring continued federal funding and improved data collection through 2031.