Abstract: Why is this research important? Whilst most service personnel make a successful transition from military to civilian life, this transition can pose significant challenges for some ex-service personnel. Despite over 1000 servicewomen leaving the military annually in the United Kingdom (UK), research has largely focused on ex-servicemen, leaving a gap in our understanding of the experiences of ex-servicewomen. Studies have linked problematic military to civilian transitions in exservice personnel to adverse outcomes like financial instability, poor mental and physical health, and strained relationships. To address the lack of research that explores women’s needs in military to civilian transition, the King’s Centre for Military Health Research (KCMHR) was commissioned by the Forces in Mind Trust (FiMT) to examine the barriers and facilitators ex-servicewomen experience making a successful and sustainable transition to civilian life in the UK. The SUpporting Successful TrAnsItioN study, i.e. the ‘SUSTAIN’ study took place over 2022-2024 to address this gap in research.