What Is the Estate Tax Exemption for a Noncitizen Spouse?

The federal estate tax exemption for a non-citizen spouse is the same amount that applies to any other beneficiary — $15 million for deaths in 2026 — but the unlimited marital deduction that lets citizen spouses inherit any amount tax-free is not available.¹ Anything a citizen spouse leaves to a non-citizen spouse above that $15 million exemption is subject to federal estate tax at rates up to 40%, unless the assets pass through a Qualified Domestic Trust (QDOT), which defers the tax rather than eliminating it.²

Why the Marital Deduction Doesn’t Apply

Federal law is blunt: if the surviving spouse is not a U.S. citizen at the time of the decedent’s death, no marital deduction is allowed.² Permanent residency doesn’t change the result. A green card holder who has lived in the United States for decades is treated the same as someone who has never set foot in the country. The reasoning behind the rule is practical. After the first spouse dies, a non-citizen surviving spouse could leave the United States with the inherited wealth, and the IRS would have no way to collect estate tax when that second spouse eventually dies.

The decedent’s own exemption still works normally. Up to $15 million in 2026 can pass to anyone, including a non-citizen spouse, without federal estate tax.¹ It’s the excess that creates the problem. At the top 40% rate, a $25 million estate passing to a non-citizen spouse would owe roughly $4 million in tax — tax that would have been zero if the spouse were a citizen.

Portability makes the gap wider. The transfer of a deceased spouse’s unused exemption to the surviving spouse, which effectively doubles the combined exemption to $30 million for citizen couples in 2026, is generally unavailable when the surviving spouse is not a U.S. citizen.³ That makes using the first spouse’s full exemption through direct bequests, rather than routing everything to the surviving spouse, an important part of the plan.

The Qualified Domestic Trust Workaround

The only way to claim the marital deduction for property passing to a non-citizen spouse is to route it through a QDOT.² The QDOT doesn’t erase the estate tax. It holds the assets inside a trust structure the IRS can monitor, deferring the tax until the surviving spouse receives principal or dies. Miss a compliance requirement, and the entire deferred tax comes due immediately.

Trustee Rules

At least one trustee must be a U.S. citizen or a domestic corporation. This U.S. trustee is personally responsible for withholding and paying the deferred estate tax whenever principal leaves the trust, and the trust document must give the trustee that withholding power.⁴ Without it, the trust fails to qualify. The surviving spouse receives all trust income, paid at least annually, and income distributions are not taxable events under the QDOT rules.⁵

Security for Larger Trusts

QDOTs holding more than $2 million (valued at the decedent’s date of death, before debts on those assets) must meet one of three added security conditions:

At least one trustee is a U.S. bank or other domestic financial institution.
The U.S. trustee furnishes a bond to the IRS equal to 65% of the trust’s fair market value.
A qualified financial institution issues an irrevocable letter of credit for the same 65% amount.

Trusts at or below $2 million face lighter rules: an annual statement reporting assets and their location, with notice to the IRS if the trust later crosses the $2 million threshold.

The Election Deadline

Structural compliance isn’t enough. The deceased spouse’s executor must make an irrevocable QDOT election on Form 706, the federal estate tax return, by its due date including extensions.² Property can be transferred or irrevocably assigned to the trust on or before that deadline. Missing the filing date is one of the most costly mistakes in non-citizen spouse planning, because the estate tax then becomes due with no chance to establish the trust after the fact.

When the Deferred Tax Comes Due

The QDOT creates a holding pattern. Three events end it. The first and most common is a distribution of principal to the surviving spouse — any non-income distribution triggers estate tax on the amount distributed.⁵ The second is the death of the surviving spouse, when remaining principal is taxed at its value on that date. The third is the trust ceasing to qualify — for example, the U.S. trustee resigns without replacement, or required security lapses. When qualification fails, the entire remaining principal becomes immediately taxable.

One narrow exception exists. Principal distributions made on account of hardship are exempt if the need is immediate and substantial and relates to the surviving spouse’s health, maintenance, education, or support (or the same needs of anyone the spouse is legally obligated to support).⁶ The spouse must also show the funds cannot be obtained from other reasonably available sources. Liquid assets like publicly traded stocks or certificates of deposit count as available; closely held business interests, real estate, and tangible personal property do not.

The tax itself is calculated using the first deceased spouse’s rates and unified credit, as if the marital deduction had never been claimed.⁵ Each taxable distribution stacks on prior ones, so spreading distributions across years does not lower the rate.

Jointly Owned Property Is a Trap

Married couples often hold real estate and accounts jointly, and the usual rules change when the surviving spouse is not a citizen. Normally, when citizen spouses hold property as joint tenants or tenants by the entirety, only half the value is included in the first spouse’s estate. That 50/50 rule does not apply here.⁷

The IRS instead presumes the entire value of jointly held property belongs to the decedent’s estate. The executor can reduce that amount only by proving, with records, how much of the original purchase price the surviving spouse actually contributed. This is the “consideration furnished test.” If a couple bought a home for $800,000 using a joint account where the decedent earned 60% and the surviving spouse 40%, then 60% of the current value is included in the estate. Only the portion included in the decedent’s gross estate can be transferred to a QDOT.⁷

The lesson is documentation. Keep clear records of each spouse’s financial contributions to jointly held assets: bank statements, deposit records, proof of separate earnings used for purchases. Without a paper trail, the IRS will include 100% of the asset’s value.

Ways to Reduce or Avoid the Problem

The QDOT deferral works, but it locks the surviving spouse into a compliance structure that runs for the rest of their life. Several strategies shrink the amount that has to pass through a QDOT, or eliminate the need for one.

Naturalization Before the Filing Deadline

The cleanest fix is for the surviving spouse to become a naturalized U.S. citizen before the deceased spouse’s Form 706 is filed. If that happens, the unlimited marital deduction applies as though the citizenship limitation never existed, but only if the surviving spouse was a U.S. resident at all times between the decedent’s death and naturalization.² A spouse who leaves the country for an extended period between death and citizenship does not qualify. Portability of the deceased spouse’s unused exemption can also be elected on that Form 706 once citizenship is in hand.

If the surviving spouse becomes a citizen after a QDOT is already in place, the trust can escape the distribution tax going forward, but conditions apply. The spouse must have been a U.S. resident continuously after the decedent’s death, and either no taxable distributions were made from the QDOT before citizenship, or the spouse elects to treat prior taxable distributions as taxable gifts for their own gift and estate tax calculations.⁸ The residency piece trips up spouses who split time between the U.S. and their home country.

Annual Gifting to a Non-Citizen Spouse

The annual gift tax exclusion for transfers to a non-citizen spouse is far more generous than the standard exclusion. For 2026, a citizen spouse can give up to $194,000 per year to a non-citizen spouse without gift tax, compared to $19,000 for gifts to any other individual.⁹ Gifting over years shifts wealth, and all future appreciation on those assets, out of the taxable estate. A couple with a decade of runway could move nearly $2 million this way, with no gift tax and none of the compliance load of a QDOT.

Life Insurance Owned Outside the Estate

Life insurance proceeds are not subject to estate tax if the deceased didn’t own the policy. An irrevocable life insurance trust (ILIT) owns the policy instead of either spouse, keeping the death benefit outside the taxable estate. For non-citizen spouse planning, the ILIT provides liquid, tax-free cash the surviving spouse can access without the restrictions of a QDOT. The proceeds can also fund the estate tax bill on assets that do pass through a QDOT, so the trust doesn’t have to sell illiquid property like real estate or a family business to pay tax.

Treaty Benefits

The United States has estate tax treaties with a handful of countries that modify the standard rules. The U.S.-Canada treaty, for example, provides a nonrefundable marital credit against U.S. estate tax for certain property passing to a surviving spouse who is a U.S. or Canadian resident.¹⁰ Claiming that credit requires the executor to waive the domestic marital deduction, so it’s an either/or choice. Other countries with U.S. estate tax treaties include Germany, the United Kingdom, Japan, and France. Whether a treaty credit or a QDOT produces a better result depends on the specific numbers in the estate.

1
Internal Revenue Service. What’s New — Estate and Gift Tax
2
Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse
3
Internal Revenue Service. Frequently Asked Questions on Estate Taxes for Nonresidents Not Citizens of the United States
4
Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust
5
Internal Revenue Service. Instructions for Form 706-QDT
6
eCFR. 26 CFR 20.2056A-5 – Imposition of Section 2056A Estate Tax
7
eCFR. 26 CFR 20.2056A-8 – Special Rules for Joint Property
8
Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust
9
Internal Revenue Service. Frequently Asked Questions on Gift Taxes for Nonresidents Not Citizens of the United States
10
Internal Revenue Service. 4.25.4 International Estate and Gift Tax Examinations