South Korea has a treaty and a totalization agreement, and rates high enough to make the credit win.
Korean income tax is progressive to 45% with a local surtax on top, and there is both a US income tax treaty and a totalization agreement. For most Americans working here the foreign tax credit produces a better result than the Foreign Earned Income Exclusion, and self-employment tax is usually relieved.
Tax snapshot — South Korea
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Sources: IRS Publication 54; IRS Publication 901; US–Korea income tax treaty (1979); US–Korea totalization agreement (2001); Rev. Proc. 2025-32. Checked 28 August 2026.
What that means on your return
Teachers arriving on a first contract are the exception worth naming: in a part-year arrival, with local tax low in the first months, the exclusion can still be the better answer. It is a genuine comparison, not a default, and it is decided on your figures.
The treaty contains a teaching and research provision that has been read too widely for years. It is narrow, it is time-limited, and claiming it where it does not apply creates a position I would have to defend rather than file.
The totalization agreement generally assigns coverage to one system. Where Korean coverage applies, US SECA falls away for self-employment income — with a certificate of coverage as the evidence.
If you are in South Korea as a…
Questions I get about South Korea
I teach in Korea. Is my salary exempt under the treaty?
Almost certainly not. The teaching provision is narrow and time-limited, and it does not exempt an ordinary school or hagwon salary. The exclusion or the credit is your route, not a treaty exemption.
Does the totalization agreement remove my self-employment tax?
Where it assigns your coverage to the Korean system, yes. That needs a certificate of coverage rather than an assumption, and it is one of the first things I check for self-employed clients here.
Should I claim the exclusion or the foreign tax credit in South Korea?
It turns on your effective local rate. Where local tax is high the credit usually beats the exclusion and leaves your income counted for IRA purposes; where it is low the exclusion usually wins. Revoking the exclusion binds you for five years without IRS consent, so it is decided deliberately — that comparison is what the position review is for.
When is my return due?
15 June, under the automatic extension for filers living abroad. Form 4868 moves it to 15 October, and I file the extension free.
Do I have to file an FBAR for my Korean bank account?
If your foreign accounts together passed $10,000 at any point in the year, yes. You can file it free through FinCEN's own system. The non-willful penalty for not filing is $16,536.
I have not filed for several years. What now?
The Streamlined Foreign Offshore Procedures: three returns, six FBARs and Form 14653 certifying non-willfulness. Penalties are waived. Note that the IRS terminated the separate Delinquent FBAR Submission Procedures around 1 July 2026.
Filing from South Korea this year?
Twenty minutes with the Enrolled Agent who will prepare and sign it. Complete return, $599.
An IRS Enrolled Agent working only on US tax for Americans living abroad. I prepare and sign every return myself — 17 years in practice, 12 of them as an Enrolled Agent.