A qualified domestic trust (QDOT) is a United States estate-planning structure that allows the United States estate-tax marital deduction to apply where the surviving spouse is not a United States citizen. Normally the unlimited marital deduction defers estate tax on property passing to a spouse, but that deferral is denied for a non-citizen spouse unless the property passes through a QDOT.
A QDOT must meet statutory requirements, including having at least one United States trustee, and it imposes a deferred estate tax on certain distributions of principal during the surviving spouse's lifetime and on the property remaining at that spouse's death. The structure is relevant in mixed-citizenship Canada-United States estates, where one spouse is a United States citizen and the other is not, and cross-border planning seeks to manage exposure to United States estate tax.