Korea is regarded as a country that provides a high level of medical services despite a low burden of public health insurance premiums. However, patients face the burden of covering the costs of medical services that are not covered by health insurance, and providers face difficulties because the price of the medical service guaranteed by the health insurance system is very low. In this situation, the government is trying to expand health insurance coverage in the form of the ‘preliminary coverage system’ also known as the ‘selective coverage system’. In this system the government sets the price for a particular health care service not covered by health insurance and then the patient pays for the majority (50% to 90%) of the cost. Although it is possible to manage information about the amount of medical service usage at the national level through this system, it still places a high economic burden on patients with low incomes. In addition, since medical providers are forced to receive uniformly undervalued prices, specialized technologies that have been optimized by medical research institutions are threatened with extinction. Therefore, the preliminary coverage system needs to be reviewed before implementation of expanded coverage within this framework. First, the concept of essential medical care should be established. Based on this concept, the percentage of the cost to be paid by patients should be derived. If the preliminary coverage system is applied to medical services that are not covered by health insurance, a reasonable classification system should be developed and applied along with pricing considering customary market prices.