This chapter introduces practicing non-Department of Defense (DoD)/Veterans Administration (VA) affiliated mental health clinicians to traumatic brain injury (TBI). It describes the epidemiology of brain injury, typical signs and symptoms, and offers suggestion for assessment and intervention. The Defense and Veterans Brain Injury Center (DVBIC) is the Department of Defense's (DoD) Office of Responsibility for tracking TBI data in the US military. Mental health clinicians working with Veterans who have m-TBI should assess for how well individuals are carrying out their activities of daily living (ADLs). Veterans with m-TBI may complain of difficulties with concentration, short-term memory, problem-solving, and other cognitive challenges. The mental health professional working with Veterans who have m-TBI can make skillful and effective interventions with family members and caregivers. These interventions can include emotional support, encouragement, and, most importantly, education about m-TBI and the course of recovery from the injury.