Ryan Kelty, Meredith Kleykamp, and David Segal examine the effect of military service on the transition to adulthood. They highlight changes since World War II in the role of the military in the lives of young adults, focusing especially on how the move from a conscription to an all-volunteer military has changed the way military service affects youths' approach to adult responsibilities. The authors note that today's all-volunteer military is both career-oriented and family-oriented, and they show how the material and social support the military provides to young servicemen and women promotes responsible membership in family relationships and the wider community. As a result, they argue, the transition to adulthood, including economic independence from parents, is more stable and orderly for military personnel than for their civilian peers. At the same time, they stress that serving in the military in a time of war holds dangers for young adults. The authors examine four broad areas of military service, focusing in each on how men and women in uniform today make the transition to adulthood. They begin by looking at the social characteristics of those who serve, especially at differences in access to the military and its benefits by socio-demographic characteristics, such as age, gender, race and ethnicity, social class, and sexual orientation. Military service also has important effects on family formation, including the timing of marriage and parenthood, family structure, and the influence of military culture on families. Family formation among servicemen and women, the authors observe, is earlier and more stable than among civilians of the same age. The authors then consider the educational and employment consequences of service. Finally, they scrutinize the dangers of military service during times of war and examine the physical and psychological effects of wartime military service. They also note the sexual trauma endured both by male and female military personnel and the physical and symbolic violence women can experience in a male-dominated institution. Kelty, Kleykamp, and Segal conclude by seeking policy lessons from the military's success in facilitating the transition to adulthood for young men and women in uniform. (Contains 1 figure, 1 table, and 123 endnotes.)