Military organizations often demonstrate contrasting features compared to civilian ones, including indoctrination of military identity and mind-set. Therefore, on returning after retirement, military personnel undergo acculturation to reconnect to the civilian world. Many military retirees face difficulty readjusting in multiple professional and personal life domains, and report decreased life satisfaction due to this transition. The present review conducted a thematic meta-synthesis of 28 studies that had qualitatively assessed military to civilian transition experiences. The aim was to understand the military-civilian culture gap and identify the challenges faced during this transition. The analysis led to six themes - "Military Institutionalization, Military-Civilian Cultural Contrast, The Three S's of Transition Challenges - Stereotypes, Skills, and Support, The Losses of Identity, Reconnecting with Family, Friends, and Civilian Counterparts, and Facilitators in Transition - Covering the Military-Civilian Gap." Based on these findings, the review further presents possible intervention suggestions for retirement adjustment and future research direction.