Cross-Border Families: Non-Citizen Spouses, QDOTs, and Foreign Account Reporting

If your spouse is not a United States citizen, one of the most important assumptions in American estate planning does not apply to you. The unlimited marital deduction, which lets a citizen leave any amount to a spouse free of federal estate tax, is unavailable when the surviving spouse is not a citizen. Without planning, assets left to a non-citizen spouse above the available exemption can face federal estate tax at rates reaching 40%, due within months of death. The standard solution is a qualified domestic trust, or QDOT, which restores the marital deferral by ensuring the assets remain within reach of U.S. taxing authority. Lifetime gifting is also restricted: a citizen may give a non-citizen spouse up to $194,000 in 2026 free of gift tax, generous compared with the $19,000 annual exclusion for others but far from unlimited. Separately, families with foreign accounts face annual reporting obligations under FBAR and FATCA that carry severe penalties for non-filing, even when no tax is owed.

Why does the marital deduction not apply?

The reasoning is administrative rather than punitive. The unlimited marital deduction does not exempt assets from estate tax; it defers the tax until the surviving spouse's death, on the assumption that the assets will be taxed in the survivor's estate. That assumption fails if the surviving spouse is not a U.S. citizen, because a non-citizen might return to their home country with the assets, placing them beyond the reach of U.S. estate tax permanently. Congress responded by denying the deduction outright rather than risk losing the deferred tax.

Note that citizenship, not residency, is the test. A green card holder who has lived in the United States for decades and pays U.S. tax as a resident is still a non-citizen spouse for this purpose. Many families are surprised by this, because in almost every other respect a long-term permanent resident is treated as a U.S. taxpayer.

The exposure is real even at today's high exemption levels. The federal estate and gift tax exemption is $15,000,000 per person in 2026 under the One Big Beautiful Bill Act, discussed in the $15 million estate tax exemption, so a couple whose combined wealth sits below that amount may face no federal tax regardless. Above it, the difference between having a QDOT and not having one can be very large.

What is a QDOT, and how does it work?

A qualified domestic trust is a trust designed to hold assets passing to a non-citizen surviving spouse so that the marital deduction becomes available. Assets pass into the QDOT rather than outright to the spouse, the marital deduction applies, and estate tax is deferred rather than owed at the first death.

Several requirements govern it. At least one trustee must be a U.S. citizen or a domestic corporation, which is the mechanism ensuring assets remain subject to U.S. jurisdiction. That U.S. trustee must have the right to withhold estate tax on distributions. For larger trusts, generally those exceeding $2,000,000, additional security is required, such as a U.S. bank serving as trustee or a bond or letter of credit. The executor must affirmatively elect QDOT treatment on the estate tax return.

The trade-off is what happens to distributions. The surviving spouse may receive income from the trust without estate tax, but distributions of principal are generally subject to estate tax at the time of distribution, at the rate that would have applied at the first spouse's death. There is an exception for distributions made on account of hardship. Whatever remains in the trust is taxed at the surviving spouse's death. So a QDOT defers the tax and preserves the assets' productivity; it does not eliminate the tax the way a marital deduction does for citizens.

A QDOT can be created in the deceased spouse's estate plan in advance, which is the better approach, or in some circumstances established after death by the executor or the surviving spouse before the estate tax return is filed. The cleanest fix of all is often simpler: if the surviving spouse becomes a U.S. citizen before the estate tax return is filed, the unlimited marital deduction generally becomes available and the QDOT becomes unnecessary. For couples where naturalization is realistic, that path deserves serious consideration.

What are the lifetime gifting limits?

Gifts between spouses are unlimited when both are citizens. When the recipient spouse is not a citizen, an annual cap applies. For 2026 that limit is $194,000, indexed annually. Gifts above the cap are taxable gifts that consume the donor's lifetime exemption.

The cap is considerably larger than the $19,000 annual exclusion available for gifts to anyone else in 2026, and it creates a useful planning opportunity. A couple with meaningful assets and a non-citizen spouse can shift substantial wealth over time by using the annual limit each year, gradually equalizing their estates and reducing what would otherwise be exposed at the first death. Done consistently over many years, this can materially reduce the need for a QDOT to carry the full burden.

Care is required with joint accounts and joint property, because contributions to jointly held assets can constitute completed gifts to a non-citizen spouse in ways that would not apply between citizens. Titling should be reviewed deliberately rather than assumed.

What reporting obligations apply to foreign accounts?

These obligations apply to any U.S. person with foreign financial accounts, regardless of citizenship questions, and the penalties for failure are severe enough that compliance deserves attention even when no tax is due.

FBAR.A U.S. person must file FinCEN Form 114 if the aggregate value of all foreign financial accounts exceeds $10,000 at any point during the year. The threshold is aggregate, not per account, and it is triggered by a single moment during the year rather than a year-end balance. Signature authority over an account, even without ownership, can create a filing obligation. Penalties for non-willful violations are significant, and willful violations can reach far higher.

FATCA Form 8938.Filed with your income tax return, this reports specified foreign financial assets, a broader category than FBAR that includes certain foreign investments not held in accounts. Thresholds vary by filing status and residence, beginning at $50,000 for a single filer living in the United States and rising substantially for married filers and for those living abroad, with the highest thresholds for married couples residing overseas.

Many families must file both, since the forms serve different agencies and cover overlapping but not identical assets. Other filings may apply as well, including forms for interests in foreign corporations, partnerships, and trusts, and for the receipt of large foreign gifts or inheritances. Because these obligations are technical and the penalties disproportionate, they belong with a cross-border tax specialist rather than a generalist.

What else should cross-border families consider?

A few additional issues arise repeatedly.

Non-resident, non-citizen individuals who own U.S. situs assets, such as U.S. real estate or shares of U.S. corporations, face U.S. estate tax with an exemption of only $60,000 rather than $15,000,000, a dramatic difference that catches foreign investors in U.S. property unaware. Estate and gift tax treaties exist with a number of countries and can modify these rules significantly, so the applicable treaty should always be checked.

Foreign trusts and foreign pensions carry their own complex U.S. tax treatment, and investments that are perfectly ordinary abroad, such as non-U.S. mutual funds, may be treated as passive foreign investment companies with punitive U.S. tax consequences. Families should also confirm that estate documents drafted in one country will be recognized and administered in the other, since a will valid in one jurisdiction may not operate as intended in another.

The general point is that cross-border planning is an area where reasonable assumptions from domestic planning frequently do not hold. The foundational documents everyone needs are covered in the estate planning checklist and do I need an estate plan, but for cross-border families those documents should be drafted with specialist input.

A worked example: the cost of the assumption

The following is a hypothetical illustration. A U.S. citizen married to a long-term green card holder dies with $25,000,000 in assets, leaving everything outright to his spouse. He had assumed, as most couples do, that a spouse inherits free of estate tax.

Because his wife is not a citizen, the unlimited marital deduction is unavailable. His $15,000,000 exemption shelters part of the estate, but the remaining $10,000,000 is exposed to federal estate tax at rates reaching 40%, potentially several million dollars due within months, possibly requiring the sale of assets to pay it.

Had his estate plan directed the assets into a QDOT, the marital deduction would have applied, deferring the tax and leaving the full amount invested for his wife's benefit, with tax due only on principal distributions and on the remainder at her death. Alternatively, had she completed naturalization before the estate tax return was filed, the unlimited marital deduction would generally have been available and no QDOT would have been needed. And had the couple used the annual gifting allowance to a non-citizen spouse over the preceding fifteen years, a substantial portion of the wealth would already have been in her name. Any of the three would have improved the outcome; doing nothing produced the worst one. The example is hypothetical and simplified.

Frequently asked questions

Can I leave everything to my non-citizen spouse tax-free?Not through the unlimited marital deduction, which is unavailable when the surviving spouse is not a U.S. citizen. Amounts above your available exemption can face federal estate tax unless the assets pass into a qualified domestic trust or your spouse naturalizes before the return is filed.

Does a green card make my spouse a citizen for this purpose?No. The test is citizenship, not residency or immigration status. A long-term permanent resident who pays U.S. tax as a resident is still treated as a non-citizen spouse for the marital deduction.

What is a QDOT?A qualified domestic trust that holds assets for a non-citizen surviving spouse so the marital deduction applies and estate tax is deferred. It requires a U.S. trustee with withholding authority, additional security for larger trusts, and an election on the estate tax return.

How much can I give my non-citizen spouse each year?$194,000 in 2026, indexed annually. That is far more than the $19,000 annual exclusion for other recipients but is not unlimited, and consistent use over many years can meaningfully equalize the spouses' estates.

When do I have to file an FBAR?When the combined value of your foreign financial accounts exceeds $10,000 at any point during the year. The threshold is aggregate across all accounts and can be triggered by a single day's balance, and signature authority alone can create the obligation.

What is the difference between FBAR and Form 8938?FBAR is filed with FinCEN and reports foreign financial accounts above $10,000 in aggregate. Form 8938 is filed with your tax return under FATCA, covers a broader set of foreign assets, and has higher thresholds that vary by filing status and whether you live abroad. Many people must file both.