Background: The toll of suicide goes way beyond the death of an individual. Those exposed (defined as knowing the person) to a suicide death are at elevated risk for mental illness, physical disorders, impaired social functioning, and fatal and nonfatal suicide behavior. Conclusions from the handful of studies that have examined this topic among Veterans are limited by distinct samples, limited sample sizes and other methodological issues. Additionally, the numbers of women and minority race/ethnicity service members and Veterans in these studies were too small to examine what are likely critical differences by sex and race. Significance: This study will provide foundational information on an understudied risk factor for suicide in a cohort of Veterans at increased suicide risk – post 9/11 Veterans within six years following military separation. It will provide information to inform suicide postvention strategies that target the population of suicide bereaved post-9/11 Veterans as well as those targeting women and American Indian/Alaskan Native (AI/AN) Veterans. Innovation and Impact: (1) Use of VA data to provide the most reliable prevalence estimates for suicide exposure among Veterans to date; (2) Oversampling of vulnerable but understudied populations -- Women and AI/AN Veterans; (3) inclusion of two comparison groups to elucidate the common and unique contribution of suicide exposure to health outcomes and patterns of VA service utilization; and (4) Assessment of the formal and informal supports Veterans receive for mental health problems associated with suicide using both survey and VA healthcare utilization data. Specific Aims: (1) Evaluate differences in the prevalence of posttraumatic stress disorder (PTSD), prolonged grief disorder (PGD), and in suicidal ideation, attempts and planning among Veterans exposed to suicide compared with those exposed to other causes of sudden death and with unexposed Veterans. We will also evaluate differences by sex and race. (2) Identify modifiable moderating factors for the association between suicide exposure and negative outcomes and modifiable moderating factors for the association between suicide or sudden death exposure and negative outcomes relative to those with neither exposure. (3) Describe treatment experiences, interests, reported suicide attempts, and patterns of VA service utilization among those exposed to a suicide death compared to Veterans exposed to other sudden deaths and to unexposed Veterans. (4) Contextualize quantitative findings through interviews with a purposive sample of Veterans exposed to suicide. The interviews will focus on modifiable factors at each level of the socio-ecological model of suicide prevention to better understand targets for intervention. Methodology: This explanatory sequential mixed methods study examines outcomes associated with suicide exposure in a nationally representative sample of post-9/11 Veterans enrolled in VA healthcare. We will collect data in t...