Family carers play an important role supporting individuals with intellectual and developmental disabilities (I/DD) into adulthood. Funders of services often desire this ongoing involvement by family members yet they rarely collect data about family carers. As policy makers and planners are increasingly recognizing the need for information related to indicators of system performance, a scoping review was conducted to identify system-wide information needed about family carers of adults with I/DD that would help improve the quality of service provided.