Background: Planning for the future care of adults with an intellectual disability after the main family carer ceases their care, continues to be a sensitive and difficult time posing challenges for service providers internationally. Limited research has been undertaken on this topic as until recently people with intellectual disability usually pre-deceased their parents. This study examined ageing carers’ preferences for future care and the support systems required to make such future plans. Methods: The study was conducted in one region of the United Kingdom with a high proportion of family carers. A mixed methods design was employed. In Stage 1, a structured questionnaire was used to collate information on the health, caregiving demands and future planning preferences of 112 parent and sibling carers; aged 60yrs to 94yrs. In Stage 2, 19 in-depth semi-structured interviews were undertaken with a sample of carers to explore a range of issues around future planning.Findings: Over half of the carers were lone carers, mainly female, with many reporting a wide range of health problems. A third of these carers reported that their caregiving resulted in high levels of anxiety. The main preference of the carers was for the person to remain in the family home, with either the family and/or paid staff to support them. A minority of parent carers preferred the person to move into the home of a sibling although some favoured the person moving to a residential facility with other people with intellectual disabilities. The majority of carers did not want their relative to move into an older people’s residential/nursing facility. In the qualitative data, four main themes were identified around future planning: unremitting apprehension, the extent of planning, obstacles encountered and solutions for future planning. Avoidance, lack of guidance and a lack of appropriate residential provision were cited as obstacles to making future plans compounded by the emotional upset experienced by carers in thinking about the future. Conclusion: Findings of this study clearly identify the emotional, informational and practical supports required by these ageing family carers. These findings have national and international relevance in influencing how governments and service providers support parent and sibling carers to proactively plan for the future, and in the development of both in-home and out-of-home options when a family carer can no longer provide care. This is more urgent than ever given the growing numbers of older persons with intellectual disabilities in future decades.