Abstract: Introduction: Veterans face elevated risk of suicide and homelessness, with housing instability being a significant, independent risk factor among this population. Addressing housing instability through primary, secondary, and tertiary prevention services is crucial for improving health and mortality outcomes, though research remains limited. The objective of this study is to assess the association between receipt of primary, secondary, and tertiary homelessness prevention services and risk of suicide and all-cause mortality among Veterans within 24 months of experiencing housing instability. Methods: Data were extracted from national U.S. Department of Veterans Affairs electronic health records, 2014–2019, and mortality data from National Death Index. Logistic regressions conducted in 2024 modeled suicide and all-cause mortality using a time-discreet survival framework with person-month as the unit of analysis. Cohort included 662,682 Veterans with indicators of housing instability in electronic health records. Results: Veterans who received homeless services across the 3 levels of public health prevention had reduced odds of suicide compared to nonparticipants, while Veterans exiting these programs had higher odds of suicide (p-value ranges <0.001–0.05). Consistent results were found for all-cause mortality. Conclusions: Continued receipt of services to address housing instability is associated with reduced mortality risk. Exiting programs to address housing instability may be a vulnerable period for Veterans, and investment in homelessness prevention is crucial to reduce mortality and improve outcomes among Veterans. Ongoing support is essential to mitigate risks associated with program exit.