U.S. Tax Rules for Income Earned in Korea — 2026

Hanmi CPA · Cross-Border Tax Guide

U.S. Tax Rules for Income Earned in Korea — 2026
한국에서 발생한 소득의 미국 세금 규정 완전 정리

Every category of Korean-source income — salary, rental, business, stock gains, severance, and pension distributions — including how Korean retirement plans are treated differently from a U.S. 401(k), with employer pension contributions sometimes taxed at the time contributed rather than at withdrawal.

7 Income Categories Korean Pension ≠ 401(k) FTC Mechanics

Section 01

Master Reference Table — All Income Types 전체 소득 유형 한눈에 보기

U.S. tax residents must report every category of Korean-source income as worldwide income. The table below is the quick-reference summary; each category is explained in detail in the sections that follow.

Income Type	U.S. Form	FTC Available?	Special Issue
Korean salary 근로소득	Form 1040, Line 1a	YES general basket	Treaty Article 15 — Korea has primary rights
Korean rental income 임대소득	Schedule E	YES passive basket	U.S. depreciation rules apply (27.5/39 yr)
Korean business income 사업소득	Schedule C	YES general basket	SE tax applies unless Totalization Agreement exception
Korean stock gains (listed, individual)	Schedule D / Form 8949	USUALLY NO	Korea exempts small shareholders (소액주주) — no Korean tax to credit
Korean ETFs/mutual funds (PFIC)	Form 8621 + Schedule D	COMPLEX	Punitive excess distribution regime unless QEF/MTM elected
Korean interest/dividends 이자·배당소득	Schedule B	YES passive basket	15.4% standard withholding (14% national + 1.4% local)
Korean severance 퇴직금	Form 1040 (wages/other income)	YES general basket (if post-residency)	Taxable ONLY if received after residency start date
국민연금 (National Pension) distributions	Generally analogous to Social Security treatment	N/A — generally not federally taxable like SS	Treaty pension/social security provisions apply
IRP / 연금저축 / DC 퇴직연금 — employer contributions	Form 1040, Line 1a (potentially, at contribution)	Limited — Korea doesn't tax contributions, so no Korean tax to credit at that point	NOT treated like a 401(k) — may be currently taxable when contributed, not deferred until withdrawal

Section 02

Korean Salary 근로소득 근로소득

Employment Income

Form 1040, Line 1a · General FTC Basket

Report gross Korean salary on Form 1040 Line 1a, converted to USD
Korean income tax withheld (소득세 + 지방소득세) creditable via Form 1116, general basket
Korean social insurance (건강보험, 국민연금 employee contribution) NOT creditable
Only salary earned/received during the U.S. residency period is reportable

Treaty Article 15: Korea has primary taxing rights on employment exercised in Korea. The U.S. still requires worldwide reporting; the FTC (not exclusion) prevents double taxation.

Section 03

Korean Rental Income 임대소득 부동산 임대소득

Real Property Rental Income

Schedule E · Passive FTC Basket

Report gross rent and deduct Korean expenses (property tax, repairs, management fees) on Schedule E
U.S. depreciation rules apply: 27.5 years (residential) or 39 years (commercial) — NOT Korean depreciation schedules
Depreciation basis: Korean purchase price converted to USD at the acquisition-date exchange rate
Korean rental tax withheld creditable via Form 1116, passive basket

Treaty Article 6: Korea has primary taxing rights on income from Korean real property. U.S. depreciation often creates a U.S. tax loss even when Korean cash flow is positive.

Section 04

Korean Business Income 사업소득 개인사업·프리랜서 소득

Business Profits / Self-Employment

Schedule C · General FTC Basket

Report net Korean business/freelance income on Schedule C
Subject to U.S. self-employment tax (15.3%) UNLESS the U.S.–Korea Totalization Agreement exception applies (Certificate of Coverage from Korean NPS for those contributing to 국민연금)
Korean business tax (종합소득세) creditable via Form 1116, general basket

Treaty Article 8 — Permanent Establishment: Korea has primary taxing rights if a PE exists in Korea (office, factory, branch, etc.). The PE concept matters most for incorporated Korean businesses, not typical sole-proprietor freelance income.

Section 05

Korean Stock Gains 주식 양도소득

Capital Gains — Listed Stocks

Schedule D / Form 8949

Fully taxable in the U.S. at LTCG/STCG rates based on total holding period (from original Korean purchase date)
Korea exempts small shareholders (소액주주) from capital gains tax on KRX-listed stock sales — this means there is usually NO Korean tax to credit
Cost basis and proceeds must each be converted to USD at the respective transaction-date exchange rates

Treaty Article 13: Generally exempts capital gains from taxation by the source country (Korea) for residents of the other country, except for real property and PE-connected gains — which aligns with Korea's domestic exemption for small shareholders.

⚠ Korean ETFs and Mutual Funds Are a Completely Different Category — PFIC: Individual Korean company stocks (Samsung, Hyundai, etc.) are not PFICs and follow the standard capital gains treatment above. Korean ETFs (KODEX, TIGER) and mutual funds (펀드) are almost universally Passive Foreign Investment Companies (PFICs) — subject to a separate, punitive tax regime requiring Form 8621. The default §1291 excess distribution regime taxes gains at the highest ordinary rate (37%) plus compound interest dating back to acquisition, unless a timely QEF or Mark-to-Market election was made. The single best action: liquidate Korean funds before the U.S. residency start date — sales while still a non-resident are Korean-source gains not subject to U.S. tax at all.

Section 06

Korean Interest & Dividends 이자·배당소득 이자소득 · 배당소득

Interest and Dividend Income

Schedule B · Passive FTC Basket

Report Korean bank interest and dividends on Schedule B
Standard Korean withholding: 14% national + 1.4% local = 15.4% total — creditable via Form 1116, passive basket
Schedule B Part III: must check "Yes" to the foreign account question if Korean accounts exist, regardless of balance
Triggers FBAR (>$10,000 aggregate) and potentially FATCA (>$50,000+ depending on filing status/residence)

Section 07

Korean Severance 퇴직금 퇴직소득

Severance Pay

Form 1040 · General FTC Basket

Received BEFORE the U.S. residency start date: Not taxable in the U.S. — Korean-source income of a non-resident alien.
Received AFTER the U.S. residency start date: Fully taxable in the U.S. — even though the entire underlying employment was performed in Korea before the move. Payment date (not work-performance date) controls for cash-basis taxpayers.
Korean severance tax withheld (퇴직소득세) creditable via Form 1116, general basket
Request 퇴직소득 원천징수영수증 from the Korean employer before departure — this is the primary FTC documentation

Section 08

Korean Pension Income — How It's Actually Taxed 한국 연금소득 과세 방식

❌ Common Assumption

"Korean retirement plans work like a U.S. 401(k) — contributions go in tax-deferred, grow tax-deferred, and are only taxed when withdrawn (distributed). So IRP and 연금저축 distributions are simply 'taxable when received,' just like a 401(k) withdrawal."

✓ Actual U.S. Tax Position

Korean retirement plans were not designed to meet U.S. tax-qualification standards. The IRS does not automatically grant 401(k)-style deferred treatment to Korean IRP, 연금저축, or DC-type 퇴직연금 plans. Employer contributions to these plans may be treated as currently taxable compensation to the employee in the year contributed — not deferred until the eventual distribution — depending on the plan's vesting and funding structure under U.S. nonqualified deferred compensation principles.

⚠ This Is Not a Settled, Simple Rule — and Getting It Wrong Risks Double Taxation: If an employer's contributions to a Korean IRP or DC pension plan were properly treated as currently taxable to the employee in the contribution year (because the U.S. tax analysis determined the arrangement doesn't qualify for deferral), and the taxpayer ALSO reports the eventual distribution as fully taxable income when received — without accounting for the basis already taxed — this results in taxing the same dollars twice. Conversely, treating the contributions as automatically tax-deferred (assuming 401(k)-style treatment that doesn't actually apply) and then reporting the full distribution as taxable income later may UNDER-report income in the contribution years. Both errors are common because most general guidance defaults to the (incorrect) assumption that foreign pension plans work like U.S. qualified plans.

By Pension Type

국민연금 (National Pension) distributions: Generally treated analogously to U.S. Social Security under treaty principles (Article 20-adjacent social security provisions) — employer and employee contributions are not currently taxed, and distributions in retirement follow social-security-like treatment rather than ordinary pension income treatment. This is the one Korean pension category where the "simple" treatment is largely correct.
IRP (개인형 퇴직연금) — employer-funded: Requires case-specific analysis of vesting and funding. If treated as a funded, vested arrangement without U.S. qualified-plan status, employer contributions may be currently taxable to the employee in the contribution year. If correctly identified and taxed at contribution, the basis (already-taxed amount) should not be taxed again upon distribution — only the subsequent investment growth would be taxable at distribution.
연금저축 (personal pension savings) — self-funded: Contributions made by the individual from their own after-(Korean)-tax income are generally treated more straightforwardly — since the individual is contributing their own funds (not receiving an employer benefit), there is less of the deferred-compensation characterization issue. Growth within the account, however, may still raise PFIC concerns if invested in Korean funds (연금저축펀드) — see Section 5.
퇴직연금 DC (defined contribution, employer-funded): Same analysis as IRP — employer contributions require examination of whether U.S. principles treat the arrangement as funded/vested at the time of contribution.

What to Do: Any Korean-American or Korean national who is a U.S. tax resident with an employer-sponsored IRP, DC 퇴직연금, or similar plan should have a CPA review the specific plan documents — vesting schedule, employer contribution structure, and whether the employee has an unconditional right to the contributed amounts — in the first year that contributions begin (or the first year of U.S. residency, if contributions predate it). This is not an area where generic "taxable when withdrawn" guidance can be safely applied without plan-specific review.

Section 09

5 Fully Computed Examples 실제 계산 사례 5개

Case 01 — Korean Salary, General Basket FTC

FTC Calculation

Korean salary: 40,000,000 KRW ÷ 1,370	$29,197
Korean tax withheld: 6,160,000 KRW ÷ 1,370	$4,496
U.S. tax on same income (general basket limitation)	$5,000
FTC = smaller of $4,496 or $5,000 → fully credited	Net U.S. tax: $0 (no carryover since Korean tax was less than the limit)

Note: $4,496 (the actual USD-converted Korean tax) is less than the $5,000 limitation, so there is no excess in this case. Always verify which number (Korean tax or limitation) is actually larger before describing a carryforward.

Case 02 — Korean Rental Income, Passive Basket FTC

FTC Calculation

Net Korean rental income (after U.S. depreciation)	$10,000
Korean rental tax paid	$2,000
U.S. tax on same income (passive basket limitation)	$1,500
FTC = smaller of $2,000 or $1,500	$1,500 credited; $500 carryforward (passive basket only)

Case 03 — Korean Listed Stock Gain, No FTC

Why No FTC

Gain on Korean listed stock: 5,000,000 KRW ÷ 1,370	$3,650
Korean tax: $0 (소액주주 exemption applies)	No Korean tax paid → no FTC possible
U.S. LTCG tax at 15% (if held >12 months)	$548 — paid entirely without offset

Case 04 — Korean Severance, Timing Determines Taxability

Before vs. After Residency Start Date

Severance paid before residency start date	Not taxable in U.S. — $0
Same severance paid after residency start date	Fully taxable. Korean tax withheld ($8,000) credits against U.S. tax ($6,000) — limited to $6,000; $2,000 carryforward (general basket)

Case 05 — IRP Employer Contribution, Potential Current Taxation

A Korean employer contributes KRW 4,000,000/year to an employee's IRP. The IRP is a funded, vested arrangement under the plan terms (employee has an unconditional right to the contributed amount once made).

U.S. Tax Treatment — Not "Wait Until Withdrawal"

Korea: contribution is tax-deferred (no current Korean tax)	$0 Korean tax in the contribution year
U.S. (if vested/funded under U.S. principles): contribution is currently taxable compensation	4,000,000 KRW ÷ 1,370 = $2,920 added to Form 1040 Line 1a in the contribution year — no FTC available (no Korean tax was paid on it)
At eventual distribution: only the GROWTH since contribution (not the already-taxed $2,920 basis) should be taxable	Requires tracking the U.S.-taxed basis across years to avoid double taxation at distribution

Section 10

Common Mistakes 자주 발생하는 오류

1 Assuming Korean IRP/연금저축/DC pension distributions are "simply taxable when received," like a 401(k) withdrawal. Korean retirement plans do not automatically receive U.S. tax-deferred treatment. Employer contributions to funded, vested arrangements may be currently taxable in the contribution year — making the later distribution partially or wholly a return of already-taxed basis, not new taxable income.
2 Treating individual Korean stocks and Korean ETFs/funds the same way. Samsung Electronics stock is not a PFIC; KODEX 200 ETF is. Applying capital gains treatment to a PFIC (or PFIC treatment to an individual operating stock) produces incorrect tax results in either direction.
3 Mixing general and passive basket FTC calculations. Korean salary/business/severance taxes (general basket) and Korean interest/dividend/rental/capital gains taxes (passive basket) require separate Form 1116 limitation calculations. They cannot offset each other.
4 Reporting severance based on when the work was performed rather than when it was paid. For cash-basis taxpayers, the payment date controls. Severance for 15 years of Korean employment, paid after the U.S. residency start date, is fully taxable — even though virtually all the underlying service was performed pre-residency.
5 Expecting Korean tax credit on listed stock gains. Korea's small-shareholder exemption (소액주주 면세) means most individual Korean stock sales generate no Korean tax — and therefore no FTC. The full U.S. capital gains tax applies without offset.
6 Not liquidating Korean PFIC funds before the U.S. residency start date. Sales completed while still a non-resident are Korean-source gains, entirely outside U.S. tax jurisdiction. The same funds held into the residency period become subject to the punitive PFIC excess distribution regime.
7 Crediting Korean social insurance contributions as if they were income taxes. 건강보험 and 국민연금 employee contributions are not creditable on Form 1116 — only 소득세 and 지방소득세 (actual income taxes) qualify.
8 Not getting a CPA review of IRP/DC pension plan documents before assuming any tax treatment. This is a genuinely complex, fact-specific area of U.S. international tax law. Generic guidance — including this guide — cannot substitute for review of the actual plan structure, vesting terms, and funding mechanics by a CPA with cross-border deferred compensation experience.

Section 11

Hanmi CPA Insight

Practitioner's Note

The seven categories of Korean-source income in this guide share underlying mechanics — worldwide income reporting, FTC by basket, treaty primary-taxing-rights provisions — but each has distinct traps. The capital gains category is the most counterintuitive: Korea's generous small-shareholder exemption, which is genuinely good news for Korean residents, becomes a U.S.-only tax burden once the same person is a U.S. tax resident, because there is no Korean tax left to credit. Meanwhile the severance category rewards precise timing — the same payment, identical in every respect, is either fully taxable or entirely tax-free in the U.S. depending solely on which side of the residency start date it falls.

The Korean pension treatment is one of the more consequential points relative to commonly circulated guidance. The assumption that Korean retirement plans work "just like a 401(k) — taxed only when withdrawn" is the default mental model most people bring to this topic, and it is not reliably correct. The U.S. tax system's treatment of foreign retirement plans depends on whether the specific plan, examined under U.S. funding and vesting principles, qualifies for deferral — and Korean IRP and DC pension plans were never designed with that U.S. framework in mind. The practical consequence is that some Korean-American employees with employer pension contributions may have unreported current income in the contribution years, which compounds each year the issue goes unaddressed, while others may be at risk of double-counting income if they treat both the contribution and the eventual distribution as fully taxable without basis tracking.

The throughline across all seven categories is that the U.S. tax treatment of Korean income rarely mirrors Korea's own domestic treatment — sometimes more favorably (the FTC often zeroes out U.S. tax on salary), sometimes less favorably (PFIC, the listed-stock no-FTC trap, and potentially the pension contribution issue). A CPA-driven category-by-category review, rather than a single blanket assumption that "Korea already taxed it so it's handled," is what actually protects against both double taxation and under-reporting.