Portability is a valuable strategy for reducing federal gift and estate taxes, which enables a surviving spouse to use the unused portion of their deceased spouse’s gift and estate tax exemption. Currently, this exemption stands at $12.92 million, but it’s slated to revert to an inflation-adjusted $5 million on January 1, 2026.

Unfortunately, portability isn’t automatically available; it requires the deceased spouse’s executor to make a portability election on a timely filed estate tax return (Form 706). And many executors fail to make the election because the estate isn’t liable for estate tax and, therefore, isn’t required to file a return.

The Numbers Don’t Lie

When there’s a surviving spouse, estates that aren’t required to file an estate tax return should consider filing one for the sole purpose of electing portability. The benefits can be significant, as the following example illustrates:

Bob and Carol are married. Bob dies in 2023, with an estate valued at $3.92 million, so his unused exemption is $9 million. His estate doesn’t owe estate tax, so it doesn’t file an estate tax return.

Carol dies in 2026, with an estate valued at $15 million. For this example, let’s say the exemption amount in 2026 is $6 million. Because the exemption has dropped to $6 million, her federal estate tax liability is $3.6 million [40% x ($15 million – $6 million)].

Had Bob’s estate elected portability, Carol could have added his $9 million unused exemption to her own for a total exemption of $15 million, reducing the estate tax liability on her estate to zero. Note that, by electing portability, Bob’s estate would have locked in the unused exemption amount in the year of his death, which wouldn’t be affected by the reduction in the exemption amount in 2026.

Take Action Before Time Expires

If your spouse died within the last several years and you anticipate that your estate will owe estate tax, consider having your spouse’s estate file an estate tax return to elect portability. Ordinarily, an estate tax return is due within nine months after death (15 months with an extension), but a return solely for purposes of making a portability election can usually be filed up to five years after death. Contact us with any questions regarding portability.