In 1977 a survey was conducted of all state-licensed, state-contracted, and state-operated residential facilities serving mentally retarded people in the United States. The survey was replicated in 1982 and this report summarizes and compares the results of the two surveys. Results indicate that the overall size of the residential service system for mentally retarded individuals remained stable between 1977 and 1982; however, the characteristics of the population served changed, with residents in 1982 being slightly older and more severely handicapped than 1977 residents. The number of smaller facilities increased substantially and trends indicate that public facilities are being replaced by smaller community-based programs that serve severely/profoundly handicapped individuals. Changes in the Intermediate Care Facilities for the Mentally Retarded program (ICF-MR) generally paralleled those of the residential care system as a whole. (CL)