United Statesの税務居住ルール：183日テスト
183日のしきい値
United Statesにおける183日ルールの仕組み
The US uses the Substantial Presence Test: 31 days in the current year plus a weighted 183 day count over three years. Green card holders are always resident.
ローリング12カ月ウィンドウ. これは、暦年の区切りだけでなく、任意の日付から遡って計算されることを意味します。ローリングウィンドウは数字が毎日変わるため、手動での追跡が難しくなります。
183日を超えると、United Statesは税務居住者としてあなたの全世界所得に課税する可能性があります。具体的な影響は、個人の状況、適用される租税条約、所得の種類によって異なります。
日数のカウント方法
The Substantial Presence Test reaches three years back. It counts every full day you spent in the US this year, plus one third of your days from last year and one sixth of the year before that. If that weighted total crosses 183 and you were also in the US for at least 31 days this year, you are a US tax resident under domestic rules. Green card holders are tax residents regardless of where they spend the year.
1日とみなされる条件
Any day you were physically inside the US for any portion of it counts as a full day, arrival and departure included. The IRS carves out limited exceptions for transit through certain airports, medical conditions that prevented you from leaving, and days as a teacher, student, or government related individual.
日数以外の判定基準
Even when the day count says you are caught by the Substantial Presence Test, the Closer Connection Exception (filed on Form 8840) can pull you back to non resident status. You need fewer than 183 days in the current year, a tax home in another country, and a closer connection to that country than to the US. Treaty tiebreakers can also help if you would otherwise be dual resident.
特別税制
US citizens and green card holders are taxed on worldwide income no matter where they live. The Foreign Earned Income Exclusion (FEIE) shelters more than $130,000 of foreign earned income from US tax when you meet the bona fide residence test or the physical presence test, but the filing obligation itself never goes away.
租税条約
US treaties typically include a "saving clause" that prevents citizens from using the treaty to claim non resident status, no matter where they live. Non citizens caught in dual residency can still use the tiebreaker tests in any applicable treaty to assign residency to the other country.
よくある質問
Do I file US taxes if I am a citizen living abroad full time?
Yes. The US taxes citizens on worldwide income regardless of where they live. You may end up owing nothing after the Foreign Earned Income Exclusion or foreign tax credits, but the filing obligation itself stays in place.
How does the Closer Connection Exception work?
If you stayed under 183 days in the current calendar year, kept a tax home in another country, and had a closer connection to that country than to the US, you can file Form 8840 to be treated as a non resident, even when the Substantial Presence Test would otherwise classify you as resident.
Does a green card make me a US tax resident?
Yes. The green card test applies from the day the card is issued until it is officially abandoned or revoked, even if you live abroad full time.
公式情報源: https://www.irs.gov/individuals/international-taxpayers/substantial-presence-test