South Korea has ranked second among members of the Organization for Economic Cooperation and Development in terms of the burden arising from medical costs. The National Health Insurance Corporation, quoting an OECD survey, said South Koreans pay 41-point-three percent of their medical costs with the rest covered in insurance, placing the nation second after Mexico. The ratio is far higher than that of other countries in the 30-member group, which ranges from ten to 20 percent.