The number of foreign subscribers, including South Koreans living abroad, stood at 971,199 as of end-December last year, or 1.9 percent of the total subscribers tallied at 51.07 million, according to the data by the National Health Insurance Service.
The figure represents a 68.4 percent surge from six years earlier.
The sharp increase came as more foreigners visited South Korea to study or work.
The number of foreigners staying in South Korea came to 2.37 million as of end-December last year, up 8.6 percent from the previous year.
Chinese citizens, including ethnic Koreans, were the largest at 1.08 million (45.2 percent), followed by Thais with 197,764 (8.4 percent) and Vietnamese with 196,633 (8.3 percent).
With the number of foreign subscribers rising fast, the government has decided to strengthen the management of subscriber requirements to prevent foreigners from receiving medical treatment and leaving without paying insurance fees.
Starting in July, all foreigners who stay in South Korea for six months or longer will be required to sign up for the health insurance program.
In December last year, Seoul raised the minimum stay requirement to receive benefits from the program to six months from three months. (Yonhap)