Evaluations of large datasets preclude the ability to directly measure individual experiences, instead relying on proxies to infer certain constructs. Blast exposure is a construct of study currently in its infancy, resulting in diverse definitions and measurement across studies. The purpose of the present study was to validate Military Occupational Specialty (MOS) as a proxy for blast exposure in combat veterans. 256 veterans (86.33% male) completed the Salisbury Blast Interview (SBI) and Mid-Atlantic MIRECC Assessment of Traumatic Brain Injury (MMA-TBI). MOS was collected through record review and categorized into low and high risk for blast exposure. Chi-square analyses and t-tests compared SBI metrics between MOS categories. ROC analyses evaluated diagnostic accuracy of MOS category in determining blast exposure severity. Veterans in high-risk MOS were more likely to have experienced blast and deployment TBI (p's<.001) compared to low-risk MOS. ROC analyses indicated good specificity (81.29-88.00) for blast and TBI outcomes, suggesting that low-risk MOS is generally associated with an absence of blast and TBI outcomes. Sensitivity was low (36.46-51.14), indicating that MOS risk level was not a good predictor of the presence of these outcomes. Results demonstrate that high-risk MOSs will identify individuals with blast exposure and TBI history whereas low-risk MOSs will capture a highly variable group. Accuracy of MOS categorization was not acceptable for diagnostic-level tests; however, results support its use as a screening measure for a history of exposure to blast, use in epidemiological studies, and considerations for military policy.