Combined medical expenses at South Korea’s five largest general hospitals surged by more than 1 trillion won ($882 million) for the past five years, data showed Tuesday. The five are Seoul National University Hospital, Severance Hospital, Samsung Seoul Medical Center, Asan Medical Center and Catholic University of Korea Seoul St. Mary’s Hospital.

The National Health Insurance Service data, released by Rep. Kim Sang-hoon of the Liberty Korea Party, showed that the combined medical expenses at large medical institutions amounted to 21.11 trillion won in 2016, taking up 32.7 percent of the total medical costs of 64.57 trillion won in Korea.

Medical expenses at tertiary hospitals accounted for 51.8 percent of the total. Those at the big five took up 34.2 percent, or 3.7 trillion won, of the medical expenses at large general hospitals.

As of 2016, there were 89,919 medical institutions, including 298 general hospitals and 43 tertiary hospitals, which are designated by the government for treatment of acute diseases.

During the past five years, the total medical expenses went up 7.8 percent annually, whereas those at tertiary hospitals jumped 10 percent a year and the big five, 9.9 percent a year.

The five largest general hospitals saw their medical expenses quickly rising, compared to the growth of the number of patients. The number of patients who visited the five hospitals increased about 13 percent, from 1.96 million in 2012 to 2.22 million last year. However, their medical expenses went up 37 percent from 2.7 trillion won to 3.7 trillion won during the same period.

“Rather than expanding the health insurance coverage, the government should overhaul the medical service system excessively centered on large hospitals. If left uncorrected, the current regime will force mom-and-pop clinics to shut down, and primary care will be under greater threat. We urgently need follow-up measures,” Kim said.