Background: Placement behaviours of families of adults with intellectual disabilities has received little or no attention of researches to date. Methods: A prospective design was adopted to examine changes in placement decisions of 75 family carers over a 12-month period. Factors associated with changes were also examined. Results: Over 12 months, 30 families moved closer to considering an out of home placement. Of these 14 had placed their relative in out of home care. Proactive coping strategies were significantly associated with an increased likelihood of continued home care. Conclusion: While the results were similar to studies with children with intellectual disability (ID) or autism spectrum disorder (ASD), a move out-of-home occurred more quickly for adults. This may reflect current social policy and societal attitudes where moving out of home is more normative for adults with ID. The lack of association with all but one carer or care recipient factors suggest that changes in placement tendencies for adults may differ from that of children.