Abstract: Objective: The Suicide Crisis Syndrome (SCS) has accumulated support as an indicator of suicide risk in patient settings; however, it has not been evaluated in military/veteran populations. The present study tested the factorial structure, measurement invariance, latent mean differences, and incremental validity of a SCS proxy variable developed from the Military Suicide Research Consortium's (MSRC) Common Data Elements (CDE). Method: A secondary data analysis of 6,556 adults (40.5% current service members, 27.0% veterans, 26.6% civilians) who participated in MSRC-funded studies was conducted. CDE items were selected to form a SCS proxy, which was tested in subsequent analyses. Results: A bifactor model exhibited superior model fit to alternative configurations. This model was partially invariant across those with differing histories of suicide and military service. Individuals with a history of suicidal ideation or attempts had more severe SCS symptoms than those without such history, and the SCS factor was incrementally related to lifetime suicide attempts and their characteristics above other relevant factors. Conclusions: These findings provide evidence for the generalizability of the SCS to military service member and veteran populations, as well as the potential utility of proxy measures as an assessment tool in settings in which lengthy measures may be prohibitive.