AbstractTreatment efforts for psychiatric patients traditionally are organized according to diagnosis, length of stay, age, and level of management difficulty. The current study, prompted by an attempt to reorganize services for 178 patients at a regional psychiatric hospital, examined the incidence of 72 problems exhibited either in the community prior to admission or within the institution. Factor and cluster analyses were used to identify clinically important subgroups of patients. Implications of the results for institutional organization also are discussed.