How to Elect Portability (DSUE) on Form 706 in 2026
Portability lets the surviving spouse add the deceased spouse’s unused federal estate tax exemption (the DSUE amount) to their own. For 2026 that means a couple can shield $30 million instead of $15 million. But portability is not automatic — the deceased spouse’s estate must elect it on Form 706. This guide covers the mechanics, the deadline, and the common traps.
What portability does
The executor elects to let the surviving spouse use the deceased spouse’s unused exclusion (the DSUE). Without the election, the first spouse’s exemption is lost. With it, the combined federal shelter is $30 million in 2026.
The filing requirement
The executor files Form 706 (Estate Tax Return) and makes the portability election, even when no tax is due. Many estates that owe $0 still must file solely to lock in portability for the survivor.
Deadline and simplified filing
The general deadline is 9 months after death, with a 6-month extension available. The IRS permits a simplified Form 706 — without a full asset valuation — for estates below the filing threshold that only need the portability election. Late elections can be permitted for certain estates under Rev. Proc. 2022-32.
Traps to avoid
The biggest trap is simply forgetting to file: no Form 706 means no portability and a lost exemption. Also watch remarriage and a prior DSUE from an earlier spouse; states that do not recognize portability (Massachusetts is one) where a credit-shelter trust may still be needed; and the fact that the DSUE is fixed at the deceased spouse’s applicable exclusion and is not inflation-adjusted for the survivor.
Model the savings
Estimate the benefit with our Estate Tax Simulator, and review the underlying concept in What Is Portability (DSUE)?.