Qualified domestic trust (QDOT)

If your spouse isn't a US citizen and your estate is large enough to risk being vulnerable to estate taxes, you can use a qualified domestic trust (QDOT) to allow your spouse to enjoy the benefit of the marital deduction until his or her own death.

In short, the marital deduction means that one spouse can leave the other all his or her assets free of estate tax. The inherited assets become part of the estate of the surviving spouse, and unless the combined value is less than the exempt amount, estate tax could be due at the death of that spouse.

The difference, with a QDOT, is that at the death of the surviving, noncitizen spouse, the assets in the trust don't become part of his or her estate, but are taxed as if they were still part of the estate of the first spouse to die. Income distributions from the trust are subject to income tax alone, but distributions of principal may be subject to estate tax.