Purpose: The purpose of this study is to generate an understanding of becoming an assistant practitioner (AP) through a work-based learning programme so that work-based learning programmes are designed and delivered to enable practitioners to develop the knowledge, skills and attitudes to undertake new roles from within. Design/methodology/approach: The study, based on the lived experience of developing from a health-care assistant to an AP, was based on the philosophical assumption of understanding an experience at a particular time. Constructivism (Denzin and Lincoln, 2008) provided the conceptual framework and phenomenology of the theoretical perspective. Experiential learning, action, reflection and professional knowledge framed the literature review to inform understanding at the commencement of the study. Eight participants were selected, through purposive sampling, from one acute NHS Trust in South East England. Their matron and mentor were interviewed for contextualisation. Interviews occurred at 3 stages, 4 months after commencing the foundation degree (FD), 16 months after commencing the FD and 6 months after completing the FD. Each transcript was considered before moving to the next transcript, this allowed super-ordinate themes to be considered within groups before ascertaining similarities and differences across groups. The emergent and super-ordinate themes were synthesised to inform three over-arching super-ordinate themes. Findings: The following over-arching super-ordinate themes emerged from the analysis of the participants' transcripts from the three phases of the study: recognising the transition; the transition was not linear but was complex and influenced by the individuals' behaviour, their ability to reflect and take action and to demonstrate professional knowledge. Supporting the journey; the workplace culture needed to support experiential learning and provide time and space to facilitate reflection. Being an AP; a change in professional knowledge and behaviour resulted in enhanced confidence and self-belief and the ability to be an AP. Originality/value: This study, based on the lived experience of developing from a health-care assistant to the AP, where participants remained in their place of work rather than undertake placements which is a requirement of regulated programmes, demonstrated that individuals need to recognise the consequences of the behaviours, engage in experiential learning, take action and demonstrate a change in professional knowledge.