Abstract: Little is known about preservice depressive symptoms, their linkages to subsequent depressive symptoms, and the role of sociodemographic factors in shaping depressive symptoms of those who serve in the military. Using data from the National Longitudinal Study of Adolescent to Adult Health (n n = 18,910), we modeled depressive symptom trajectories from baseline ( M age = 15.67) through midlife and compared differences in depressive symptoms between participants who did and did not enter military service. Those who served in the military went on to develop lower levels of depressive symptoms than civilians during their prime military service years, even after accounting for sociodemographic factors that shape pathways into military service. Differences in depressive symptoms by military affiliation were no longer significant by their mid-30s. Results provided a more complete account of depressive symptom patterns associated with military service by including data on individuals before and during military service.