Since 1977, population coverage has expanded in South Korea; starting with salaried workers and employees, then advancing to more disadvantaged populations (including lower-income and unemployed), and finally self-employed and public workers. South Korea achieved universal health coverage in 1989, when coverage extended to the remaining urban and rural populations. In the following years, the government has continued to reform the health care system and delivery mechanisms in response to social and political changes, including adopting a single-pay system in 2000.

The National Health Insurance Service (NHIS) is the single-insurer in charge of operating and managing the national health insurance scheme. Along its journey toward UHC, the NHIS has experienced many reforms and challenges such as the enrollment of the informal sector workers, integration of multiple insurers, introduction of long-term care insurance to the aging, and integrated collection of four major social insurance contributions. The Health Insurance Review & Assessment Service (HIRA) evaluates medical fees, quality of care, and the adequacy of medical service.