Yes, in most cases. US citizenship is kept for life, regardless of where you live. If you are a US citizen by birth, by descent or by naturalization, if you hold a green card or if you regularly spend time in the United States, you remain required to report your worldwide income to the IRS. French nationals born in the United States who never lived there, sometimes called accidental Americans, are legally in the same position. Only a formal and costly renunciation of citizenship ends this obligation.

FATCA is a 2010 US law that requires your French bank to report your accounts to the IRS, and requires you to report them on Form 8938. FBAR, the FinCEN Form 114, is a separate filing, due as soon as your foreign accounts together exceed 10,000 dollars at any point in the year. The penalties for non-reporting are heavy, up to half of the account balance for willful violations. A voluntary disclosure remains possible, provided it is started before the authorities contact you.

The 1994 France-United States tax treaty provides a tax credit mechanism for most types of income. Your salaries, dividends, capital gains and real estate income declared in one country give rise to a tax credit in the other. Double taxation arises mainly on poorly characterized income (Roth IRA, RSUs, trusts) or on structures that one authority does not recognize. A precise reading of each item of income under both regimes avoids most problem situations.

Potentially, yes. The French authorities apply to US trusts a framework that does not match the American categories (revocable, irrevocable, grantor). Poorly characterized, or with no clearly determined beneficiary or share, a trust can be taxed at gift and inheritance transfer duties of up to 60%, regardless of its nature in the United States. The characterization is prepared in advance, ideally before the trust is set up or before you become a French tax resident, and in coordination with your US trustee.

In principle, these US retirement plans fall under the 1994 treaty: the amounts received, whether as an annuity or as a lump sum, are taxable in the United States, and France grants a tax credit that neutralizes its own taxation, keeping only an effect on the rate applied to your other income. The risk therefore does not come from automatic double taxation, but from the characterization of each plan. The Roth IRA, already tax-free on the US side, is a debated point in this respect, and not all vehicles enjoy the same recognized treatment. It is this reading, done ahead of any withdrawal, that secures your retirement accounts and avoids an unfavorable re-characterization.

The Article 155 B impatriate regime can significantly lighten your taxation on return: a partial exemption on certain income, and on your investment income from foreign sources, for eight years. But it is more demanding than people think: it requires returning to take up salaried employment or a company director’s role in a business established in France. A return without that kind of professional framework, or settling back as a self-employed worker, does not open this right. Hence the value of a French-American audit six to twelve months before the return: it tells you whether this regime can be activated and, if not, how to structure your wealth, your sales and your retirement accounts differently before the options close.