Background: We describe current care arrangements in England for children, young people and adults with learning disabilities and behaviour that challenges, and estimate their comparative costs. Materials and Methods: A two-round Delphi exercise was performed in March and April 2014, followed by a costing exercise. Results: The study finds a mixed picture: participants reported that 60-87% of children, 66-88% of young people and 34-47% of adults were likely to be living within the community. Annual cost of care would range between £39 612 and £74 876 for children, between £35 235 and £52 832 for young people and between £81 478 and £94 799 for adults. Conclusion: While residential-based care may continue to be necessary for respite or for individuals with particular needs, community-based care may be an economically attractive alternative, supporting the inclusion of people with learning disabilities and behaviour that challenges within their communities, potentially at a lower cost. [This article was also written by the BC Delphi Group.]