Starting April 1st, 2022, foreigners visiting Korea who have completed their COVID-19 vaccinations will be exempted from mandatory quarantine. Quarantine exemption will be available for those who have completed their third dose of the COVID-19 vaccine or received two doses (one dose for Janssen) at least 14 days prior but within 180 days.
Overseas visitors must enter their vaccine records to Q-CODE prior to arriving in Korea and scan the provided QR code upon immigration. Q-CODE will require personal information (passport number), entry information (departure country, airline, address in Korea, phone number), and vaccine records.
Q-CODE website: cov19ent.kdca.go.kr
For US-travelers, please refer to the link: https://kr.usembassy.gov/022420-covid-19-information/