Abstract: In this scoping review of military service–related traumatic brain injury (TBI) studies, authors map the progress of TBI research from January 2015 through June 2025 and identify overlaps and gaps in specific areas. They also highlight areas that received the most-focused investment. Service-related TBI is a signature wound of war, affecting more than 500,000 service members since 2000, and special operations forces (SOF) are at particularly high risk because of frequent blast exposures and repetitive neurological stresses. Many TBIs go undiagnosed or are mild, yet they often co-occur with such conditions as posttraumatic stress disorder and depression and lead to significant long-term health impacts. Despite substantial federal and private investment, TBI research remains fragmented and siloed, highlighting the need for a comprehensive assessment of research efforts and funding in this critical area. By highlighting both research achievements and persistent gaps, this study provides a road map for policymakers, funders, and researchers to align priorities to close knowledge gaps. A more coordinated research agenda is essential to advance prevention, diagnosis, treatment, and long-term recovery and ensure comprehensive care and support for all service members and veterans living with TBI.