You can hold dual citizenship in Korea and the US, but only under specific conditions set by Korean law. The United States allows dual nationality without restriction. South Korea generally does not, and it forces most adult dual citizens to pick one nationality by strict deadlines, with a narrow exception for people who were born into both citizenships and file the right paperwork on time. For Korean men, the choice is bound up with mandatory military service, and missing a single deadline before age 18 can lock in that obligation for years.
Why the US Side Is Simple and the Korean Side Is Not
US law does not prohibit holding a second nationality. You will not lose US citizenship by acquiring or using a Korean passport, and the government treats dual status as a routine fact rather than a legal problem.1Library of Congress. Afroyim v. Rusk, 387 U.S. 253 (1967) The one practical limit: when you are inside Korea, the US Embassy’s ability to help you is reduced, because Korea has every right to treat you as its own citizen and apply its own laws to you.2Travel.State.Gov (U.S. Department of State). Dual Nationality
Korea’s Nationality Act runs the other direction. The default rule is one nationality per adult. A Korean citizen who voluntarily naturalizes as a US citizen loses Korean nationality automatically, at the moment US citizenship is acquired. No application is needed for the loss to take effect. The former Korean citizen is required to report the loss to the Ministry of Justice with supporting documents, and the Minister then publishes notice in the official gazette.3Easy to Find, Practical Law. Nationality – Renunciation and Loss of Nationality4Statutes of the Republic of Korea. Enforcement Decree of the Nationality Act Filing this notification does not preserve the Korean citizenship — that is already gone — but it clears the records and prevents complications on future visits.
So if you are an adult Korean citizen thinking about naturalizing in the US, expect to lose your Korean nationality. The circumstances in which someone actually holds both come down almost entirely to people who were born with both, plus a few later-life exceptions.
Keeping Both Citizenships Through the Pledge of Non-Exercise
The main path to real dual citizenship is being born into it. A child born in the United States to Korean parents typically holds US citizenship by birth on US soil and Korean citizenship through parentage. These birthright dual nationals are not forced to choose right away, but they hit a hard deadline in early adulthood.
Before turning 22, a birthright dual citizen must file a Pledge of Non-Exercise of Foreign Nationality with the Korean Ministry of Justice.5KoreanLII. Dual Nationality The pledge is a written commitment not to exercise the rights of your foreign nationality while inside South Korea. Filing it lets you keep Korean citizenship without giving up your US passport. Missing it opens the door to a Ministry of Justice order forcing you to pick one nationality, and potentially stripping the Korean one.
The practical effect of the pledge is that on Korean soil, you are treated as a Korean citizen and nothing else. You use your Korean passport to enter and leave, you cannot invoke US consular protection against Korean authorities, and you are subject to every obligation Korean nationals face, including taxes and, for men, military service. Outside Korea, your US citizenship works normally.
Military Service: The Deadline That Traps Korean Men
For male dual citizens, the highest-stakes deadline in the entire system comes before the pledge deadline. All male Korean citizens are subject to mandatory military service, and dual citizenship does not create an exemption. The cutoff is March 31 of the year a male dual citizen turns 18. Before that date, he can renounce Korean nationality and permanently walk away from the service obligation.6Embassy of the Republic of Korea in New York. Multiple Nationals’ Renunciation of Korean Nationality
After that date, the picture changes sharply. A male dual citizen who did not renounce in time generally cannot give up Korean nationality until he has either completed military service or reached the age at which the obligation expires. He may also run into travel restrictions if he enters or stays in Korea during that window. Families who did not know the deadline existed often find out too late.
The 2022 Late-Renunciation Exception
A Nationality Act amendment that took effect on October 1, 2022 created a narrow way out for men who missed the pre-18 deadline. A dual citizen subject to military service can apply to renounce Korean nationality after the cutoff, but only if he shows reasonable grounds for missing it and meets one of two residency conditions:7Korea Immigration Service (Ministry of Justice). Amended Nationality Act – Special Cases on the Relinquishment of Korean Nationality
- He was born outside Korea and has lived abroad continuously since birth.
- He left Korea before turning six and has generally lived outside Korea since.
The Ministry of Justice weighs each application by looking at where the applicant was born, how often and how long he visited Korea, whether he ever used rights reserved to Korean citizens, and whether granting the waiver would be fair to men who did serve. Frequent extended visits to Korea, or use of Korean-only benefits, make approval much less likely.
Regaining Korean Nationality After 65
Former Korean citizens aged 65 and older can apply to reinstate Korean nationality while keeping their US citizenship, provided they intend to live in Korea. Unlike the standard reinstatement process, which requires giving up the other citizenship, this senior pathway allows real dual status. The application must be filed at an immigration office inside Korea, not at a consulate abroad.8Embassy of the Republic of Korea in the USA. Reinstatement of Korean Nationality for Korean Adoptees
Required documents include a reinstatement application, identity statements, a valid US passport and naturalization certificate, Korean family relationship certificates issued within three months, and an apostilled FBI background check. The fee is $200. As with birthright dual citizens, the restored dual national must sign a pledge not to exercise foreign nationality while in South Korea.
US Tax Obligations Follow You to Korea
US citizenship carries tax obligations no matter where you live. A dual citizen in Seoul owes US taxes on Korean salary, investment income, and everything else, exactly as if they lived in Ohio. Dual citizens raised in Korea who have never filed a US return are often surprised to learn this.
Avoiding Double Taxation on Income
Two tools prevent double taxation. The US-Korea income tax treaty allows a credit against domestic tax for income taxes paid to the other country, so Korean income tax paid on a Korean salary can usually be credited on your US return, often eliminating US tax on that income.9Internal Revenue Service. United States-Republic of Korea Income Tax Convention The Foreign Earned Income Exclusion also lets qualifying US citizens abroad exclude a substantial portion of earned income from US tax entirely; the amount is adjusted for inflation, and you qualify by being a bona fide resident of a foreign country for a full tax year or by being physically present abroad for at least 330 days in a 12-month period.10Internal Revenue Service. Foreign Earned Income Exclusion There is no estate or gift tax treaty between the two countries, so inherited assets can be exposed to tax on both sides without the same relief.
FBAR and FATCA Reporting on Korean Accounts
Beyond the income tax return, dual citizens with Korean financial accounts face two separate reporting rules. The FBAR (FinCEN Form 114) is required if the combined value of all your foreign accounts exceeds $10,000 at any point in the year. The threshold is cumulative, so two accounts holding $6,000 each together trigger the filing.11Internal Revenue Service. Comparison of Form 8938 and FBAR Requirements
FATCA adds Form 8938 at higher thresholds. For a dual citizen living in Korea and filing individually, the triggers are $200,000 on the last day of the tax year or $300,000 at any point during the year; joint filers face $400,000 and $600,000.12Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets The two obligations overlap. Meeting one does not satisfy the other.
Penalties are steep. Failing to file Form 8938 carries a $10,000 penalty, with up to $50,000 more if you still do not file after IRS notice, plus a 40 percent accuracy penalty on any tax underpayment linked to undisclosed foreign assets.13Internal Revenue Service. FATCA Information for Individuals FBAR penalties for non-willful violations can reach $16,536 per report for 2026, and willful violations bring the greater of $165,353 or 50 percent of the account balance, with no annual cap.
Dual citizens who have fallen behind without realizing the rules may qualify for the IRS Streamlined Filing Compliance Procedures. Taxpayers living abroad who certify the failure was non-willful can use the streamlined foreign offshore procedures, which waive penalties entirely for qualifying filers.14Internal Revenue Service. Streamlined Filing Compliance Procedures
Which Passport to Use When You Travel
Korean law requires dual citizens to enter and exit South Korea on their Korean passport. A dual citizen who enters on a US passport is coming in as a foreign tourist, which misrepresents their status. Under the Immigration Act, entering in violation of passport and visa rules can bring fines up to 30 million won or up to three years’ imprisonment, and false statements in an immigration application can carry an administrative fine up to 500,000 won.15Korea Legislation Research Institute. Immigration Act
The standard practice is to carry both passports: Korean for Korean immigration, US for US immigration, and whichever one matches the destination for airline checks and transit countries.
If You Cannot Be a Dual Citizen: F-4 Visa or US Renunciation
For people who lost Korean citizenship by naturalizing in the US and who do not qualify for the senior reinstatement pathway, the F-4 Overseas Korean visa offers a practical middle ground. It is available to former Korean nationals and their direct descendants, allows long-term stays, and comes with broad work authorization. As of February 2026, the F-4 was unified with the former H-2 visitor employment visa, expanding permitted work to include general labor in industries such as construction that were previously restricted. The F-4 does not restore citizenship or give you the legal standing of a dual national, but for many former citizens under 65 it is the most realistic way to live and work in Korea.
Going the other direction, a dual citizen who wants to keep only Korean nationality can renounce US citizenship at a US embassy or consulate abroad. The State Department charged $2,350 for the process from 2014 through 2025; a fee reduction took effect in 2026. Renunciation requires an in-person appearance, a formal oath, and an exit tax filing with the IRS if your income or net worth exceeds certain thresholds. It is irrevocable.
Dual citizens who prefer to keep both nationalities and do nothing on the US side face no US legal problem. The US will continue to recognize you as a citizen indefinitely. What does not go away are the tax filings and foreign account reports, every year, for as long as you hold the passport.