Military Service Members, Veterans, and other patient populations who experience traumatic brain injury (TBI) may have increased risk of early neurodegenerative diseases relative to those without TBI history. Some evidence suggests that exposure to psychotropic medications may play a role in this association. The Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) prospective longitudinal study provides an ideal setting to examine the effects of psychotropic medication exposure on long-term neurological health of those with and without mild TBI history. In this study, we sought to develop and pilot test a self-report electronic survey instrument to measure participants' psychotropic medication histories for use across LIMBIC-CENC study sites. We developed a new survey instrument measuring psychotropic medication history and fielded it among Service Members and Veterans enrolled in a single site of the LIMBIC-CENC study to evaluate response rates and patterns, and to compare survey responses to prescription data extracted from participants' Veterans Affair (VA) records. Descriptive statistics estimated survey respondents' lifetime psychotropic medication exposures by their TBI history and other demographic and clinical characteristics of interest. We also compared survey responses to participants' VA outpatient prescription records to estimate sensitivity and negative predictive values (NPVs) for participants' self-reported medication exposures relative to this single prescription data source. Among 310 Veterans enrolled at the study site, 249 completed the survey (response rate = 80%), of whom 248 also had VA health records and were included in the analysis. Most (69%) had a history of mild TBI. Over three-fourths of survey respondents (78%) reported ever having used prescription opioids, 26% reported benzodiazepines, 50% reported muscle relaxants, 42% reported antidepressants, 13% reported non-benzodiazepine sedative-hypnotics, 15% reported stimulants, 7% reported mood stabilizers, and 6% reported antipsychotics. Veterans with, versus without, a history of mild TBI were more likely to self-report psychotropic medication history as well as have confirmed receipt of VA prescriptions for each medication class. Using VA records as a criterion standard, the sensitivity of the survey for detecting VA prescriptions ranged from 19% to 84%, while the NPVs ranged from 64% to 97%. Sensitivity and NPVs were similar for participants with, versus without, mild TBI history. Service Members and Veterans may receive psychotropic medications from multiple sources over their lifetimes. Valid methods to examine and quantify these exposures among those with a history of TBI are important, particularly as we evaluate causes of neurodegenerative disorders in this population over time. The measurement of Veterans' lifetime psychotropic medication exposures using a self-report survey, in combination with health care records, holds promise as a valid approach, but further testing and refinement are needed.