There exists a wide body of research showing that deinstitutionalization results in significant improvements in quality of life and functioning, and this has helped to sustain government policies related to deinstitutionalization. However, far less work has considered the changes that occur in the status of individuals in the time preceding their transition to the community. This study examines the changes in functional abilities, physical health, mood, behaviour, and family involvement among persons who remain in one of Ontario’s three remaining specialized institutions after the first year of deinstitutionalization. Analyses are based on information from the interRAI Intellectual Disability (interRAI ID) instrument, which has been used to assess all residents on an annual basis since 2005. Specifically, analyses are based on 826 individuals who have both a baseline (2005) and follow-up (2006) assessment. The results indicate that significant changes in functional abilities, health, and behaviour occurred over the course of one year, and that many of these differed according to the person’s age and level of cognitive impairment. Implications of findings for individual-level transition planning are discussed, as is the role of the interRAI ID in the evaluation of transitions to the community.