||This introduction begins a special issue on Military Service in the Life Course: Implications for Later-Life Health and Well-Being. It highlights the pressing need for a lifespan approach to the effects of military service that considers positive and negative effects. The first two articles focus on Vietnam veterans. Park et al. examine how captivity stressors, mental health, and individuals’ background characteristics were related to mental health 30 years after repatriation. Pless Kaiser et al. examine current health among women veterans in relation to warzone stress, and considered whether posttraumatic stress disorder symptoms mediated the effects of warzone stress on mental and physical health. In contrast, Jahn et al. examine a diverse group of veterans, drawing on theories of posttraumatic growth to explore whether the combination of combat exposure and posttraumatic stress disorder in early life affect coping with cancer in later life. Finally, Settersten, Jr., et al. examine how World War II veterans appraised specific dimensions of military service after the war and over 40 years later, as well as later-life reflections on the role of military service in their life course. In sum, these articles illustrate how the impact of potentially traumatic experiences in early life can reverberate throughout life, particularly their long-term effects (positive as well as negative) on physical and mental health. With the growing number of veterans in societies today, these articles reveal that some, but not all, may well carry their burdens of military service long after they have laid down their weapons.