The authors examined psychiatric diagnoses in administrative records for 13,201 United States military veterans who were screened for traumatic brain injury (TBI) in Department of Veterans Affairs facilities. Over 80% of the veterans with positive TBI screens had psychiatric diagnoses. Compared to veterans with negative TBI screens, those with positive screens, but without confirmed TBI status, were three times more likely to have a posttraumatic stress disorder (PTSD) diagnosis and were two times more likely to have depression and substance-related diagnoses. Among veterans with positive TBI screens, those with clinically confirmed TBI status were more likely than those without confirmed TBI status to have diagnoses for PTSD, anxiety, and adjustment disorders. These findings have implications for health care delivery and provider education.