Portability Election Calculator (DSUE)

The portability election lets a surviving spouse inherit the deceased spouse's unused federal estate-tax exemption, known as the Deceased Spouse Unused Exclusion (DSUE). For example, if the first spouse to die had a $13.99M exemption and used only $2M of it, the surviving spouse can add the remaining $11.99M DSUE to their own exemption. This effectively doubles the shelter available to a married couple. The election must be made on a timely-filed Form 706 even if no estate tax is owed. This is general education, not legal or tax advice.

The estate must file IRS Form 706 (the federal estate tax return) within 9 months of the date of death to elect portability. A 6-month extension is available by filing Form 4768, extending the deadline to 15 months. Under IRS Rev Proc 2022-32, estates that were not required to file a return (because they were below the exemption) may make a late portability election up to 5 years after the date of death by filing a complete Form 706 with "Filed Pursuant to Rev Proc 2022-32" noted at the top. Confirm current procedures with an estate attorney.

Missing the original 15-month deadline used to permanently forfeit the DSUE. IRS Rev Proc 2022-32 (effective July 2022) now provides a simplified procedure for late portability elections for estates not otherwise required to file Form 706 - the executor can file up to 5 years after death without a private letter ruling. For estates that were required to file but missed the deadline, relief may be available by requesting a private letter ruling, which costs $10,000+ and has no guaranteed outcome. Acting promptly after a spouse's death is strongly advisable.

DSUE = deceased spouse's applicable exclusion amount minus the amount used to offset the taxable estate. If Spouse A had a $13.99M exemption and a $3M taxable estate, the DSUE is $10.99M. The surviving spouse adds this to their own $13.99M exemption for a combined $24.98M shelter (at 2026 levels). If the exemption sunsets as scheduled in 2026 to roughly $7M per person, the calculation uses whatever the applicable exclusion is at the date of the first death. The DSUE is indexed to the surviving spouse's date of death exemption, not the deceased spouse's.