From May 23, 2022(KST), a supervised negative COVID-19 Rapid Antigen Test (RAT) result will be additionally accepted for all travelers entering Korea.

Either a supervised Rapid Antigen Test (RAT) taken at a hospital or clinic, or DNA amplification-based PCR test is valid. The test must be performed and the PCR negative certificate must be issued within 48 hours (two days) before the departure date. Additionally, a supervised negative COVID-19 RAT result must be issued within 24 hours prior to the departure date.

For more information, 

Immigration Guides