DSUE decisions after a spouse dies may not be automatic

When a client’s spouse dies, tax professionals often hear the same advice: preserve the deceased spousal unused exclusion (DSUE). In many cases, that advice is sound. A properly elected DSUE amount can give the surviving spouse access to the unused federal estate and gift tax exclusion of the first spouse to die, potentially reducing estate tax exposure or allowing larger lifetime gifts later.

But DSUE is not automatic, and it is not always a simple yes-or-no decision. The executor generally must file a timely, complete Form 706, United States Estate (and Generation-Skipping Transfer) Tax Return, to elect portability, even when the estate is below the federal filing threshold. If the return is timely filed and complete, portability is generally elected unless the executor affirmatively opts out.

For small-firm practitioners, the real question is not only “Should we do DSUE?”, but also “Do my clients fall into one of the situations where portability is unavailable or less valuable, and if the executor declines the election, is that decision documented carefully?”

Quick take for tax pros

In most cases, surviving spouses should at least consider preserving DSUE. The potential benefit can be substantial, especially when future asset growth, life insurance, remarriage, federal estate tax changes or unexpected inheritances could change the surviving spouse’s estate picture.

However, there are legitimate reasons an executor may not elect portability. The key is to identify those reasons early, explain the trade-offs and document the discussion.

Why DSUE gets so much attention

DSUE allows the executor of a deceased spouse’s estate to transfer unused federal estate and gift tax exclusion to the surviving spouse. If elected, the surviving spouse may use that DSUE amount in addition to their own basic exclusion amount for lifetime gifts or transfers at death.

That can be especially helpful when the surviving spouse’s financial picture changes. A client who seems comfortably below the estate tax threshold today may later inherit assets, sell a business, remarry, receive life insurance proceeds, experience rapid asset appreciation or face a reduced exclusion amount in the future.

This is why DSUE is often viewed as a protective filing. It can preserve flexibility before anyone knows exactly what the surviving spouse’s estate may look like years later.

The role of §2010(c) and Reg. §20.2010-2 in portability elections

The authority for portability comes from §2010(c), which allows a surviving spouse to use a deceased spouse’s unused exclusion when the executor makes a proper election. Under Reg. §20.2010-2, that election is generally made by filing a timely, complete Form 706, even when the estate would not otherwise be required to file. Rev. Proc. 2022-32 also gives certain estates a simplified way to make a late portability election within five years of death. And as the Estate of Minnie Lynn Sower et al. v. Commissioner shows, the IRS may later review the first spouse’s return to verify the DSUE amount.

When DSUE may not be the right move

A client may reasonably decide not to pursue DSUE when the expected benefit does not justify the complexity or cost. Common reasons include:

• No election to make or limiting factor
  • There is no surviving spouse, so there is no DSUE election to make.
  • The decedent was not eligible, such as when the decedent was a nonresident who was not a U.S. citizen at death.
  • A surviving spouse who is a nonresident and not a U.S. citizen generally may not use DSUE, except to the extent allowed by treaty.
  • A QDOT (qualified domestic trust) or noncitizen-spouse situation can delay the practical benefit of DSUE or make it less useful, because the DSUE may be only preliminary and may not be available for lifetime gifts until it is finally determined.
• Procedural or filing-related mechanics
  • The executor misses the filing deadline and cannot or does not obtain late-election relief.
  • The estate is required to file Form 706, but the executor affirmatively opts out.
• Benefit does not justify the filing
  • The expected DSUE amount is zero or very small because the first spouse used most or all of the exclusion through lifetime gifts or taxable transfers.
  • The Form 706 filing cost, valuation work and administrative burden outweigh the likely benefit.
  • The executor wants to avoid disclosure of estate details when a return would not otherwise be required.
  • The estate includes hard-to-value assets, valuation discounts or other issues that could increase audit concern.
• Planning factors may make portability less useful 
  • The surviving spouse is expected to remarry, and the last deceased spouse rule may reduce the practical value of the current DSUE.
  • State estate tax planning changes the analysis, because federal portability does not necessarily preserve a state estate tax exclusion.
  • GST planning is a priority, because the GST exemption is not portable.
  • The couple’s planning relies on trusts, QTIP planning, bypass trust planning, or other structures that better meet the family’s tax and non-tax goals.
  • The first spouse wanted control over where assets ultimately pass, especially in blended-family situations.

Should Daphne file Form 706 after Apollo's passing?

Daphne’s husband, Apollo, dies with an estate below the federal filing threshold. At first, Daphne assumes there is no reason to file Form 706 because no estate tax is due.

But Daphne owns a growing rental portfolio, and Apollo had life insurance. She may also inherit additional assets from a sibling and is considering remarriage. In that situation, DSUE may provide valuable protection, but it is not a checkbox decision. Her tax professional should review the estate size, prior gifts, life insurance ownership, state estate tax exposure, possible remarriage, and whether trust planning or lifetime gifts may be more appropriate.

The answer may still be to file. But if Daphne declines, the file should show that the DSUE option, deadline, potential benefit and reasons for declining were explained.

The role of tax professionals in DSUE decisions

The consequences of weighing the DSUE decision incorrectly can be substantial. A missed portability election can mean the surviving spouse loses access to the unused exclusion that could have sheltered future gifts or estate assets. On the other hand, filing Form 706 requires time, records, valuation decisions and professional judgment.

That is where small-firm tax professionals add value. You may be the first trusted advisor a surviving spouse contacts after death. You may also be the person who spots the issue before the filing window closes.

Mastering the DSUE checklist

Use NATP’s DSUE checklist, available to members, as a client conversation tool and file documentation aid. Review whether the estate is eligible, whether Form 706 is required or optional, whether late-election relief may be available, and whether any factors make DSUE unavailable, unnecessary or less useful.

If the executor or surviving spouse chooses not to proceed, document the discussion in writing. The strongest DSUE advice is not “always file” or “never file.” It is a clear, well-documented recommendation based on the client’s facts.