This study aimed to (1) explore views of known experts leading on transition, (2) gather insights on the essential features of transitional care models and (3) highlight opportunities for and barriers to change: to inform core elements of benchmarks for transitional care. We held three workshops ( n = 20) and used a telephone interview ( n = 1) with health and social care professionals with expertise working with young people with a range of health conditions and disabilities. The workshops included individual brainstorming and group discussion. Data were analysed using qualitative content analysis. The general consensus from stakeholders' discussions about transition was that 'things have become stuck'. Themes included: professionals' attitudes towards and knowledge about young people and transition, organizational barriers and 'lack of joined-up thinking' between services. Our work offers further insight into experts' perceptions of transition services within the United Kingdom. It is clear that there is still much to be done to improve transition, to better meet the needs of young people and parents and begin to offer equitable access to transitional care programmes. The benchmarks offer a starting point for professionals seeking to improve transition through enabling the identification of gaps in services and providing a platform to share successful practice initiatives.