The purpose of this article was to collate evidence to describe where people with mental retardation or developmental disabilities live in five developed countries: United States, Canada, England, Wales, and Australia. Family homes are important dwelling places for people with mental retardation. They are the home of the great majority of children with mental retardation and a considerable proportion of adults with mental retardation. The likelihood of placement outside the family home increases with adulthood and progressively as people age. Adults with mental retardation live in a wide variety of settings, with formal residential provision frequently dependent on the arrangements that the authorities responsible for providing service support have chosen to make. There has been a considerable move away from accommodating people in large segregated and geographically isolated institutions in the countries considered. However, the current range of accommodation includes much with a distinctively different character to the homes where other citizens live. Many people still live in larger groups than would be ordinarily found in typical homes and this may necessitate departure from the architectural norm. In all of the countries considered, there has been a recent trend towards small community settings, compatible with typical housing architecture. This appears furthest advanced in the U.S. but is discernible elsewhere. Availability of residential services at a national level varies between 100 and 155 places per 100,000 total population. Regional variation within countries is even greater. In no case is the national availability considered adequate to meet the demand arising from changing need or expectations.