This study examines the effects both of introducing and of removing copayment charges under a universal public medical care and hospital insurance program. For a period between 1968 and 1971, the Province of Saskatchewan imposed user charges of approximately 33 per cent and 6 per cent on medical and hospital services, respectively. The effects of these charges are analyzed using pooled cross-section samples of families and using both multivariate methods and experimental/control groups designs. Diagnostic- and procedure-specific analysis is also performed on the hospital data using the individual as the unit of observation. The findings of the study indicate a copayment effect of 5.6 per cent for physicians' services. No evidence could be adduced that would support the conclusion of a copayment effect for hospital services.