Although eliminating financial barriers to care is a necessary condition for improving access to health services, it is not sufficient. Given the contrasting health systems with regard to financing and organization of health insurance in the United States and Canada, there is a long history of comparing these countries. We extend the empirical studies on the Canadian and US health systems by comparing access to ambulatory care as measured by hospitalization rates for ambulatory care sensitive conditions (ACSC) in Montreal and New York City. We find that, in New York, ACSC rates were more than twice as high (12.6 per 1000 population) as in Montreal (4.8 per 1000 population). After controlling for age, sex, and number of diagnoses, significant differences in ACSC rates are present in both cities, but are more pronounced in New York. Our findings are consistent with the hypothesis that universal, first-dollar health insurance coverage has contributed to lower ACSC rates in Montreal than New York. However, Montreal's surprisingly low ACSC rate calls for further research.