This study set out to explore which practices in alternative provision (AP) settings in England made a difference to post-16 transition success into further education, training or employment. APs provide education for pupils who have been permanently excluded from mainstream schools and those directed there to improve their behaviour. In 2016, 56% of young people transitioning from AP maintained a stable placement in the following year. This study took an approach which combined the analysis of official statistics, freedom of information requests and targeted semi-structured interviews. Findings suggest that practices which increased sustained transitions included; effective and ongoing tracking of ex-students; a high-quality, core academic offer; and opportunities for students to increase their independence by taking well-measured steps outside of their main placement. Additionally, the views of staff and their involvement in, or awareness of, the broader context within which they worked were found to be important. This study evidences the value of comparing outcomes across similar types of setting to improve our understanding of effective practice.