Persons who terminated membership in a prepaid group practice when compared with continuing members have less health problems as measured by bed disability and psychologic well-being, report access difficult and inconvenient, and are less likely to have established a stable relationship with a physician in the plan. Access is perceived as a problem by continuing members, as well as by a large proportion of disenrollees. Enrollees who join the plan on the basis of more direct knowledge of its actual operation are more likely to continue in the plan, but this is not accounted for by satisfaction levels. They are also more successful in establishing stable physician relationships.