In Ireland state funded support services provide Continuing Professional Development (CPD) for teachers and school leaders. These services are staffed with teachers seconded from their schools on an annual basis for up to a maximum of five years. This study investigated the learning and experience of teachers seconded to a national cross-sectoral support service, the Professional Development Service for Teachers (PDST) and how this influences their postsecondment career. It employed qualitative interviews to explore this from the perspective of teachers previously seconded to the PDST. The theoretical framework was rooted in the field of career dynamics setting out three stages (Entry, Experience, Exit) navigated by teachers from entering the service through to their departure. This article focusses primarily on the study findings for the Experience stage while necessarily providing some key insights from the Entry phase. In the context of a considerably under-researched area both in Irish and international teacher education, the findings bring due attention to the distinct role and identities of teachers seconded as what this study calls “Continuing Teacher Educators” (CTEs). Findings show that the learning acquired by these teachers is extensive while also revealing tensions encountered in managing hybrid identities as teachers/teacher educators. Notably they expose precarious tensions between the catalytic impact of secondment and the uncertain nature of its tenure. For most, this eventuates in a premature departure from the service to other careers, paradoxically having reached proficiency as teacher educators. Recommendations centre on career pathways for teachers seconded to support services and a review of current secondment stipulations within a need to privilege transformative CPD models in the system.