Since the 1960s the Korean society has undergone a rapid transformation under government policies to achieve maximum economic growth. With the improvement of income level due to rapid economic development, the needs of populations were increased and various medical security schemes have become necessary. The medical security system is made up of two major programs: Medical security system is made up of two major programs: Medical Insurance and Medical Aid. Medical Aid is a form of public assistance, providing medical care services for low-income people. This paper addresses structural situations and problems in the programs, and then recommends its reforms. In a historical context, Korea has achieved a remarkable development in the area of medical security. nevertheless, health care benefits are not available to all. Groups of individuals belong to different insurance funds which have different cost levels and change different premiums. Premium differentiation can be interpreted as a failure to achieve one objective of universal health insurance. As far as the human aspect of care is concerned in Kores, there are the inter-related issues of high copayments, fee-for-service reimbursement, the generally low level of services, etc. Thus we need equitable measures for universal health protection. Reforms of the medical security system should concentrate on extending insurance coverage to the uninsured, equalizing differences in premium/benefit package between health plans, guranteeing equity of access to care, integrating regional insurance funds, providing free care for vulnerable groups, and containing cost.