The authors analyze health care plan and individual provider switches between prepaid and fee-for-service for a panel of depressed outpatients in the longitudinal part of the Medical Outcomes Study. The authors found that payment system switches occurred at an annual rate of about 11% in both the FFS and the prepaid sector. Married, nonwhite, and wealthier individuals were significantly less likely to leave prepaid than fee-for-service care. Patients of mental health specialists in fee-for-service had the lowest adjusted rate of plan switching (8.1%), compared to fee-for-service general medical patients (13.5%) and prepaid patients (10.1-11.7%). Patients in prepaid plans at baseline were significantly more likely to change individual providers (55% during two years) than were fee-for-service patients (31% during two years); older, sicker, and more satisfied patients were less likely to change providers. However, there was no difference in the probability of changing providers between patients switching payment types and patients staying in the baseline system. Among patients receiving prepaid care at baseline, those who switched both provider and system were significantly more likely to report dissatisfaction with their original provider as a major cause for changing providers than those who changed providers but stayed in the system. No such difference existed in fee-for-service. Patients switching from prepaid to fee-for-service became more satisfied with their health care, whereas patients switching from fee-for-service to prepaid became less satisfied. The authors found no evidence that plan switching or provider changes had any effect on functioning outcomes.