Portability can allow a surviving spouse to use a deceased spouse’s unused federal estate-tax exclusion. It is a valuable planning tool, but the unused amount does not transfer automatically just because the couple was married.
What portability transfers
The unused amount is commonly called the deceased spousal unused exclusion, or DSUE. An effective election can make that amount available to the surviving spouse for applicable federal gift- and estate-tax purposes. The amount must be calculated under the governing rules, including the deceased spouse’s taxable estate and relevant lifetime gifts.
The basic exclusion for a U.S. citizen or resident dying in 2026 is $15 million. That figure is not a blanket promise that every married couple can transfer twice that amount free of tax. Ownership, prior gifts, deductions, elections, and the circumstances of each spouse affect the analysis.
The election matters
The executor generally makes the portability election on a complete and properly prepared federal estate-tax return, Form 706. The ordinary return deadline is nine months after death, with an extension available under the applicable procedures. A return may be needed to elect portability even where the estate would not otherwise have to file because of its value.
Specified estates that were not otherwise required to file may qualify for simplified late-election relief under Revenue Procedure 2022-32, generally by filing within five years after death. That is not a universal extension for every estate or every missed filing. Eligibility should be checked promptly rather than assuming relief will be available.
Portability is not the whole plan
Portability does not transfer an unused generation-skipping transfer-tax exemption. It also does not determine who receives property, protect an inheritance from every creditor, or provide management for beneficiaries. The rules concerning a surviving spouse’s last deceased spouse and remarriage can require additional analysis.
A trust may still be useful for family, asset-management, creditor, or tax reasons. The comparison should account for future appreciation, possible basis adjustments, the survivor’s circumstances, and any state estate tax. Choosing between trust planning and reliance on portability is not simply a question of which document is shorter.
We can coordinate estate planning with your tax advisers and help identify the post-death filings needed to preserve the choices available to a surviving spouse.
Sources: IRS Form 706 instructions; IRS Revenue Procedure 2022-32; IRS current estate-tax thresholds.
Updated October 26, 2026.