"Earning an Extra 60 Million Won Monthly While Working Full-Time... Where Do 4,500 People Get Their Side Income?"

Interest, Rental Income, and More Beyond Salary
Separate Health Insurance Premiums Apart from Salary-Based Premiums
Monthly Non-Salary Premiums Alone Reach 4.24 Million KRW

Among salaried workers enrolled in health insurance, nearly 5,000 high-income earners were found to have earned more than 59.81 million KRW per month solely from secondary income last year. These individuals generate additional income from sources such as interest, dividends, and rental income, in addition to their monthly salaries from their workplaces.

According to data titled 'Status of Subjects Subject to the Maximum Monthly Income-Based Insurance Premium by Year' received on the 21st from the National Health Insurance Corporation by Kim Seon-min, a member of the National Assembly's Health and Welfare Committee (Innovation Party for Justice), in 2024, 4,494 workplace subscribers earned more than 59,812,553 KRW per month (71,775,636 KRW annually) from interest, dividends, rental income, and other sources excluding their salaries. This accounts for just over 0.02% of the total 19,883,677 workplace subscribers.

In addition to the health insurance premiums levied on their salaries, these individuals paid a separate monthly insurance premium of 4,240,710 KRW. Health insurance premiums imposed on salaried workers are divided into two types based on the source of income: the 'monthly wage-based insurance premium' (calculated by dividing the total annual wage by the number of months worked) applied to salaries received as compensation for labor, and the 'monthly income-based insurance premium (non-wage premium)' applied to income other than salaries, such as interest, dividends, and rental income.

Both types of insurance premiums have a set maximum limit. Unlike taxes, health insurance is a social insurance system designed to prevent premiums from increasing indefinitely regardless of how high income or assets may be. The maximum limit is adjusted annually based on Article 32 of the Enforcement Decree of the Health Insurance Act, reflecting socio-economic changes such as wage increases. It is linked to 30 times the average insurance premium of workplace subscribers two years prior to the year the premium is imposed (15 times for regional subscribers) and is applied for one year.

Office workers are commuting near Gongdeok Five-way Intersection in Mapo-gu, Seoul.

Last year, the maximum monthly income-based insurance premium was 4,240,710 KRW, which translates to a monthly income of 59,812,553 KRW. This maximum monthly income-based insurance premium increased from 4,240,710 KRW last year to 4,504,170 KRW this year. When converted to monthly income, the maximum limit of 4,504,170 KRW corresponds to 63,528,490 KRW. This means earning more than 63.52 million KRW per month from secondary income such as financial or rental income, excluding salary. Annually, this amounts to over 762.34 million KRW.

The criteria for imposing health insurance premiums have gradually expanded and were restructured to focus on income starting in 2018. Initially, the threshold applied to income exceeding 34 million KRW annually, but from September 2022, the standard was lowered to income exceeding 20 million KRW annually. Accordingly, in 2023, 804,951 salaried workers recorded secondary income exceeding 20 million KRW annually.