Abstract: People who serve in the United Kingdom's (UK) Armed Forces and their families are, at some point in their lives, expected to undergo a transition from military to civilian life. The civilian environment into which Service leavers and their families transition is, however, evolving, and may present various challenges as well as opportunities in relation to making a successful transition to civilian life. As part of broader research on the contemporary transition process and experiences thereof, this report examines the nature of the evolving external environment, what trends define it now and may do so in the future, and what the implications are for Service personnel, their families and support organisations. The external environment was defined as including all factors that may affect a Service leaver's or a family member's transition outcomes and experiences, but which do not relate to either (a) the Service person's characteristics, skills, behaviours or capabilities or (b) the nature of the military environment, military culture and in-Service experiences. We examined the transition environment through the lens of different dimensions of transition – education, employment, housing, social relationships, finance and health – in addition to considering cross-cutting trends such as technological innovation.