This project will explore and synthesise evidence on the implementation and sustainability of social care interventions for autistic adults. The findings will generate new information relevant to the growing policy emphasis on improving outcomes for autistic people and the persistent variability in social care support, which often lacks sustained implementation.The protocol is registered in PROSPERO (registration number CRD420261406788):Implementation and sustainability of social care interventions for autistic adults: a mixed-methods systematic review This is the first in a planned suite of mixed-methods reviews exploring implementation and sustainability of interventions across key social care groups co-led by NESSIE researchers Pauline Campbell and Julie Cowie. This article was published on Friday 1 August 2025