This report presents selected statistics gathered on residential facilities designated as mental retardation facilities and on the residents of those facilities as part of the Institutional Population Component of the 1987 National Medical Expenditure Survey (NMES). The report is divided into 4 parts. Part 1 presents general background to and overview of the National Medical Expenditure Survey, and of the data available from it. It discusses previous efforts to conduct census or sampling surveys representing all persons in residing in mental retardation facilities. It briefly summarizes the design of the NMES Institutional Population Component, limitations evident within its sample frame, and some of the cautions that derive from these limitations. Part 2 presents statistics on the characteristics of mental retardation facilities and of the residents of those facilities from the National Medical Expenditure Survey. The data analyzed and reported come from the NMES Baseline (resident) and Facility Questionnaires. Data are summarized according to three recurring groupings of facilities: (1) by operation (private for-profit, private nonprofit, and public) and size (15 or fewer and 16 or more residents); (2) by ICF-MR certification (ICF-MR certified or not certified) and size (15 or fewer and 16 or more residents); and (3) by size alone (1-6, 7-15, 16-75, 76-299, 300-799, and 800 or more residents). A brief discussion is provided on the findings presented in each of the 32 tables included in this summary. Part 3 briefly examines an alternative method of using the population estimates from NMES that may compensate for certain of the limitations in the NMES sample frame and resulting underestimation of the population of small mental retardation facilities to yield a somewhat more realistic picture of mental retardation facilities and their residents in 1987. The report ends with a brief "Summary and Conclusions" regarding the NMES study and the relevance of its findings to current issues in residential services for persons with mental retardation and related conditions.