The effects of regional health insurance on access to ambulatory care are examined in this paper. Access is measured as use-disability ratios. The data are collected in a household interview survey at Hwachon county before and after the introduction of regional health insurance. Before the introduction of regional health insurance, low-income class has less contacts with physicians than high-income class. This disparity in accessibility among economic classes is reduced with the health insurance coverage, but not removed, even after adjusting for health need.