Tools
Japan US Expat Tax Filing Checker
Are you a US citizen or green-card holder living in Japan and unsure what you have to file with the IRS? Answer a few questions and this free checker builds a personalized list of the US filing obligations that likely apply to you, from FBAR and Form 8938 to the NISA and iDeCo PFIC trap. It is general guidance based on your answers, not tax advice.
This checker gives general guidance from the answers you enter, not tax advice or a determination of your filing requirements. US filing obligations depend on your full situation, and the rules around PFICs (NISA, iDeCo, Japanese funds), foreign-corporation reporting, and catch-up filing are technical. Use it to see what to ask about, then confirm with a qualified cross-border professional. Thresholds shown reflect 2025 rules and can change.
What US expats in Japan actually have to file
Living in Japan does not end your US tax obligations. The United States taxes its citizens and green-card holders on worldwide income wherever they live, so most Americans in Japan must file a US return every year even when, after the Foreign Earned Income Exclusion or Foreign Tax Credit, they owe nothing. On top of the return itself, several information reports can apply, and the penalties for missing them are far larger than any tax usually at stake. The checker above flags which ones likely apply to you; this section explains the big ones.
FBAR and Form 8938: reporting your Japanese accounts
If your foreign financial accounts together exceed $10,000 at any point in the year, you file the FBAR (FinCEN Form 114), separately from your tax return. The threshold is an aggregate across all accounts, not per account, and it includes Japanese bank, brokerage, and many pension accounts. Form 8938 (FATCA) is a separate IRS filing with much higher thresholds for Americans abroad, $200,000 on the last day of the year or $300,000 at any time for single filers, and double those amounts for married filing jointly. Many expats must file both.
The NISA and iDeCo PFIC trap
This is the most expensive surprise for Americans in Japan. A Japanese NISA, iDeCo, or ordinary Japanese mutual fund or investment trust (toushin) is almost always a Passive Foreign Investment Company (PFIC) for US tax. PFICs carry a punitive US tax regime and require a separate Form 8621 for each fund, with calculations most consumer software cannot handle. The Japanese tax break does not carry over to the US side, and the US treatment can erase the benefit, so it is worth getting advice before you invest, not after.
Foreign companies and equity compensation
If you own 10% or more of a Japanese (or any non-US) company, you are likely a Form 5471 filer, an information return whose penalty starts at $10,000 per form per year, with possible GILTI tax on the company's profits. (Officers and directors can also be filers when a US person acquires a 10% or greater stake.) RSUs and stock options are US-taxable and interact with both Japanese tax and the Foreign Tax Credit, so timing and double-tax relief need care.
Behind on filing? There is a penalty-free path
If you have unfiled US returns from prior years while abroad and your failure to file was non-willful, the IRS Streamlined Filing Compliance Procedures usually let you catch up, often without penalties, by filing three years of returns and six years of FBARs. Coming forward through the right program is far cheaper than being found first.
Frequently asked questions
Do US citizens living in Japan have to file US taxes?
Yes. The US taxes citizens and green-card holders on worldwide income regardless of where they live, so moving to Japan does not end your filing obligation. The Foreign Earned Income Exclusion and the Foreign Tax Credit often reduce the tax owed to $0, but you generally must still file to claim them.
Is a Japanese NISA or iDeCo a PFIC for US tax?
Almost always. NISA and iDeCo accounts typically hold Japanese mutual funds or investment trusts, which are Passive Foreign Investment Companies under US rules. That triggers the punitive PFIC tax regime and a separate Form 8621 per fund, and the Japanese tax advantage does not transfer to the US side.
What is the FBAR threshold for an American in Japan?
$10,000 in aggregate across all of your foreign financial accounts at any point in the year. It is not a per-account threshold and is not based on year-end balances, and Japanese bank, brokerage, and many pension accounts count toward it.
I have not filed US taxes since moving to Japan. What should I do?
Do not simply start filing the current year and ignore the past. If your prior non-compliance was non-willful, the IRS Streamlined Filing Compliance Procedures can bring you current, usually penalty-free. Have a cross-border professional confirm the right path before you file.