Abstract: Introduction: Transitioning from the military can be a stressful time in a military member?s life. Although evidence shows several factors are associated with a difficult transition, little is known about the long-term association of adjustment to civilian life and long-term mental health. Methods: Using the 2013 and 2019 longitudinal components of the Life After Service Survey, this study assessed the association between self-reported adjustment to civilian life in 2013 and self-reported mental health in 2019. Results: The logistic regression analysis showed that participants who reported a difficult transition in 2013 were 2.50 times more likely to report fair or poor mental health in 2019 (N = 2,015). In addition, participants who screened positive for posttraumatic stress disorder and those who reported fair or poor mental health in 2013 were 2.75 and 4.61 times more likely, respectively, to report fair or poor mental health in 2019. Discussion: The findings emphasize the importance of examining perceptions of the transition experience as a factor in long-term Veteran mental health.