Types of environmental support provided to adults with mental retardation in group homes after transfer from a large state institution were compared. Substantial differences in the functioning of the group homes were found even though the service structure was held constant. Community adjustment was compared for matched groups of residents of the group homes. Differences in community adjustment occurred for residents in group homes with significantly different functional features. The findings indicate that resident outcome was generated by the interaction of several factors in combination. Both structural and functional features of facilities must be considered in any evaluation of the effectiveness of community programs.