Are NISA and iDeCo PFIC problems for Americans in Japan?
Short answer: Japan's tax-free treatment of NISA and iDeCo has no bearing on US tax: both accounts can still hold Passive Foreign Investment Companies, and most Japan-domiciled mutual funds and ETFs are PFICs for US taxpayers. NISA generally only lets US persons buy Japanese securities in practice, while iDeCo contribution options may be restricted to Japanese funds — so Americans typically use these accounts narrowly, if at all, rather than assuming either one is automatically safe.
Written and reviewed by Anthony Walsh, Selanis. Last reviewed 2026-10-09.
Why it works this way
A PFIC is a foreign company where most income is passive or most assets produce passive income; nearly every Japanese investment trust, Japan-domiciled ETF and J-REIT meets that test, regardless of whether the wrapper around it is tax-free in Japan.
Most Japanese brokerages that offer NISA restrict US-taxpayer clients to Japanese securities because of their Qualified Intermediary agreements with the US, which in practice limits a NISA account to individual Japanese shares (not funds) for Americans at most providers, though a small number of brokers have begun allowing US-domiciled ETFs inside NISA.
iDeCo is a defined-contribution pension; its underlying fund menu is reviewed for PFIC exposure separately from the pension wrapper itself, and the investment options available often have no non-PFIC fund choice, which is why many Americans hold iDeCo in cash-equivalent options where that is available.
The expensive mistake: Assuming a 'tax-free' Japanese account is automatically US-tax-free
NISA and iDeCo are not recognised by the IRS. Japanese tax-free status is irrelevant to whether a fund inside the account is a PFIC requiring Form 8621.
What to do
- Check what your NISA or iDeCo provider actually allows — Confirm whether individual Japanese stocks, cash, or US-domiciled ETFs are available to a US-taxpayer account.
- Screen every fund for PFIC status before buying — Treat any Japanese investment trust or ETF as a PFIC until confirmed otherwise.
- Keep the bulk of investable savings in US-domiciled holdings — Use a broker that still serves US persons in Japan for the core portfolio.