Background Improvements in care and treatment have led to more young adults with life-limiting conditions living beyond childhood, which means they must make the transition to adult services. A systematic review highlighted an acute lack of evidence on transition services for young people with palliative care needs.

Methods A realist evaluation approach using a mixed methods design with four phases of data collection was employed. Phase one involved the development and distribution of a questionnaire survey to health, social, educational and charitable organisations providing transition services to young adults with 104 individual responses from 29 organisations. Phase two involved interviews with eight young adults; phase three consisted of two focus groups with parents/carers and phase four involved interviews with 17 service providers. Data were thematically analysed seeking to identify organisational factors influencing the quality of care.

Results Eight interventions were identified associated with an effective transition. How interventions are considered to work were inferred and contextual factors were identified.

Conclusions Transition should be acknowledged as a key need for young adults with life-limiting conditions.An effective transition should be seen as a core responsibility for both children's and adult services. In addition to the transition interventions, there should be consideration for how the interventions work and the contextual factors that could influence whether the interventions are effective.