Do You Pay Tax on Korean Stock Gains in the U.S.?
한국 주식 양도소득의 미국 세금 — 환율 메커니즘과 대주주 기준 2026

Overview — Worldwide Gains, USD Calculation 전세계 양도소득 — 달러 기준 계산

A U.S. tax resident must report gains from selling Korean stocks as worldwide capital gains, calculated in USD using the exchange rates applicable to the purchase and sale — regardless of whether Korea taxed the gain, whether the funds stayed in a Korean brokerage account, or whether the stock traded only on KRX (KOSPI/KOSDAQ).

소액주주 vs. 대주주 — The Korean Exemption's Exact Limit 소액주주 vs. 대주주 — 한국 비과세의 정확한 한도

Korea exempts small shareholders (소액주주) from capital gains tax on listed stock sold on the exchange — but this exemption has a precise boundary. Crossing into 대주주 (major shareholder) status removes the exemption entirely for that stock, and the threshold is lower than many investors assume.

• Assessment date: December 31 of the prior year determines 대주주 status for sales during the following year. A Korean-American whose single-stock holding crosses KRW 5 billion at any year-end becomes subject to Korean capital gains tax (20%–30%, plus local surtax) on all sales of that stock during the following year — even sales executed on the exchange.
• Per-stock, not portfolio-wide: The KRW 5 billion threshold applies separately to each individual stock holding — diversifying across many stocks does not pool the thresholds together, but a single concentrated position can cross the threshold on its own.
• If 대주주 status applies, Korea DOES tax the gain — meaning the Foreign Tax Credit becomes available for that specific stock's sales, unlike the standard 소액주주 case where there is no Korean tax to credit.

The Currency Mechanism — Direction Matters 환율 메커니즘 — 방향이 핵심

Because Korean stock purchases and sales are converted to USD using the exchange rate on their respective transaction dates, currency movement between purchase and sale changes the USD gain relative to the KRW gain. The direction of this effect depends on which way KRW moved — it is not a one-directional phenomenon that always produces a larger USD gain.

Exchange Rate Method — More Flexible Than Assumed 환율 적용 방법 — 생각보다 유연함

• Transaction-date rates are the most precise and most commonly used method for individual stock sales — converting the purchase price at the purchase-date rate and the sale price at the sale-date rate produces the most accurate USD gain/loss for each specific trade.
• The IRS yearly average rate is also an accepted method, applied consistently — for taxpayers with numerous small trades throughout the year, using the published IRS yearly average rate for both the cost basis and proceeds calculations is administratively simpler and is an accepted alternative, provided it is applied consistently across the relevant transactions.
• Whichever method is chosen, consistency is required — mixing transaction-date rates for some trades and average rates for others within the same tax year, without a documented and consistent approach, risks inconsistent or incorrect reporting.
• For high-value or infrequent trades (e.g., a single large stock sale), the transaction-date rate is generally preferable for accuracy, since it reflects the actual economic exchange that occurred on that specific date.

Holding Period Rules 보유기간 규정

• Held more than 12 months: long-term capital gain — 0%, 15%, or 20% federal rates (2026 thresholds) depending on total taxable income.
• Held 12 months or less: short-term capital gain — taxed at ordinary income rates up to 37%.
• The holding period runs from the original purchase date, including any period held before the owner became a U.S. tax resident — a Korean stock purchased years before moving to the U.S. and sold afterward generally qualifies for LTCG treatment based on the full holding period.

Korean ETFs and Funds — PFIC 한국 ETF·펀드 — PFIC 규정

• FTC for PFIC distributions is narrow: Korean tax withheld on PFIC fund distributions may be creditable, but the credit mechanics under the §1291 regime are more limited than standard passive-basket FTC — consult a CPA for the specific PFIC computation.
• The most effective planning action remains pre-residency liquidation: Korean ETFs and funds sold before the U.S. residency start date generate Korean-source gains outside U.S. tax jurisdiction entirely — avoiding the PFIC regime altogether for those specific holdings.

Korean Dividends — Taxed Separately 한국 배당소득 — 별도 과세

• Korea withholds 15.4% on dividends(15% national + 1.4% local surtax for individual Korean residents and similar treaty-coordinated rates for U.S. persons) at the source.
• Report on Schedule B, converted to USD at the rate applicable on the payment date or the IRS yearly average rate (consistent with the method used elsewhere on the return).
• FTC available for the Korean withholding, Form 1116, passive basket — separate from any capital gains FTC analysis.
• Qualified vs. non-qualified dividend treatment: Dividends from Korean stocks held directly may qualify for preferential qualified dividend rates if specific holding-period and stock-type requirements are met; dividends from PFIC-classified Korean funds generally do not qualify for these preferential rates.

Korean ADRs 한국 ADR

• Korean American Depositary Receipts trade on U.S. exchanges in USD — this simplifies the currency conversion question for the ADR shares themselves (no purchase/sale currency conversion needed since the ADR is already USD-denominated), but does not eliminate the underlying Korean company's Korean tax characteristics.
• Korean withholding on ADR dividends still applies — the depositary bank typically passes through the dividend net of Korean withholding tax, and the U.S. holder still claims the FTC for that withholding on Form 1116, same as a directly-held Korean stock.
• ADR capital gains follow standard U.S. capital gains rules — since the ADR itself is the asset being sold (in USD), there is no separate currency conversion step for the gain calculation, unlike directly-held KRW-denominated shares.

Step-by-Step Process 단계별 절차

• Step 1 — Gather Korean brokerage records: trade confirmations, purchase/sale dates, KRW amounts, dividend statements, and any Korean withholding records (relevant primarily if 대주주 status applies or for dividends).
• Step 2 — Check 대주주 status for any single-stock position approaching or exceeding KRW 5 billion in year-end value, or the relevant ownership percentage thresholds.
• Step 3 — Convert each transaction to USD using transaction-date rates (most common for individual sales) or the IRS yearly average rate (applied consistently).
• Step 4 — Report each sale on Form 8949, then summarize on Schedule D.
• Step 5 — Claim FTC if Korean tax was paid(대주주 sales, or PFIC distribution withholding) — Form 1116.
• Step 6 — File PFIC forms (Form 8621) for any Korean ETF, mutual fund, or wrap account holdings.
• Step 7 — File FBAR/FATCA if Korean brokerage accounts exceed the applicable thresholds.

5 Fully Computed Examples 실제 계산 사례 5개

Common Mistakes 자주 발생하는 오류

• 1 Assuming currency depreciation always inflates the USD-reported gain. KRW weakening between purchase and sale reduces the USD value of sale proceeds relative to a flat exchange rate — this can turn a won-denominated gain into a dollar-denominated loss, not an inflated gain. The direction depends on which way KRW actually moved.
• 2 Not checking 대주주 status for a large, concentrated single-stock position. The KRW 5 billion per-stock threshold (or 1%/2%/4% ownership thresholds by exchange) is assessed at each year-end and can be crossed without the investor actively tracking it — converting the entire following year's sales of that stock from Korean tax-exempt to fully Korean-taxable.
• 3 Believing only transaction-date exchange rates are permitted for stock sales. The IRS yearly average rate, applied consistently, is also an accepted method — transaction-date rates are simply more precise and more commonly used for individual trades, not the only permitted approach.
• 4 Treating individual Korean stocks and Korean ETFs/funds identically. Samsung Electronics stock follows standard capital gains rules; KODEX 200 ETF is a PFIC subject to a fundamentally different and more punitive tax regime.
• 5 Not filing Form 8949 for each individual stock sale. Each transaction requires its own line entry with USD-converted proceeds and basis — not a single aggregated figure for all Korean stock activity during the year.
• 6 Assuming ADRs avoid Korean tax exposure on dividends. While ADR capital gains involve no separate currency conversion (since the ADR trades in USD), Korean withholding still applies to the underlying dividends — the FTC mechanics are the same as for a directly-held Korean stock.
• 7 Not reporting Korean dividends separately from capital gains. Dividends (Schedule B) and capital gains (Schedule D/Form 8949) are distinct income categories with separate FTC baskets and separate qualification rules (qualified dividend rates vs. LTCG rates).
• 8 Not liquidating Korean ETFs/funds before the U.S. residency start date. Sales completed while still a non-resident generate Korean-source gains entirely outside U.S. tax jurisdiction — avoiding the PFIC regime altogether for those specific holdings.

Hanmi CPA Insight