New Hampshire Estate Tax Portability: Should You File Form 706 When the First Spouse Dies?

When the first spouse dies in New Hampshire, surviving spouses should strongly consider filing Form 706 — even when no federal estate tax is owed and even when the estate is nowhere near the $15 million threshold. The reason is the portability election: a provision in the federal tax code that allows the surviving spouse to "inherit" the deceased spouse's unused federal estate tax exemption. Used correctly, portability can shield an additional $15 million (in 2026) from federal estate taxes when the surviving spouse eventually dies. Skipping it costs nothing today and can cost millions in the future.

This is the most underused planning decision in New Hampshire estate administration — partly because New Hampshire's reputation as a tax-free state leads executors to assume Form 706 simply does not apply to them.

What Portability Is and Why It Matters

The federal estate tax exemption in 2026 is $15 million per individual. A married couple, properly structured, can effectively shelter $30 million — but only if the first spouse's unused exemption is preserved through the portability election.

Without portability: When the first spouse dies with an estate well below the $15 million threshold, the unused portion of that spouse's exemption is lost. When the surviving spouse dies with a combined estate large enough to trigger federal estate tax, only the surviving spouse's own $15 million exemption is available.

With portability: The executor files Form 706 on the first spouse's death (even though no tax is owed). This "locks in" the first spouse's Deceased Spousal Unused Exclusion (DSUE) — the portion of their $15 million exemption they did not use. The surviving spouse can then add this DSUE to their own exemption, effectively doubling their protection.

Example in the New Hampshire context:

The first spouse dies in 2026 with a total gross estate of $3 million. No federal estate tax is owed — the estate is well below the $15 million threshold. The remaining unused exemption is $12 million. If the executor files Form 706 and makes the portability election, the surviving spouse can use their own $15 million exemption plus the $12 million DSUE — a combined shelter of $27 million when they die.

If the executor does not file Form 706, the $12 million DSUE is gone. The surviving spouse has only their own $15 million exemption. Any estate above $15 million at the surviving spouse's death is taxable at the federal estate tax rate (beginning at 18% and reaching 40% on amounts over $1 million above the threshold).

For New Hampshire residents — who often own appreciated real estate, retirement accounts, life insurance, and investment portfolios accumulated over decades — the combined estate at the second death can easily exceed a single exemption. Portability is what prevents that outcome.

Who Should File Form 706 for the Portability Election

Filing Form 706 for portability is worth evaluating when:

• The decedent was married and had a surviving spouse. Portability applies only to married couples — it cannot be transferred to children, siblings, or other heirs.
• The combined estate of both spouses could exceed $15 million at the surviving spouse's death. This includes real estate (appreciated values, not purchase prices), retirement accounts, life insurance death benefits, investment portfolios, and any business interests. People routinely underestimate combined estate values because they focus on liquid assets rather than the full gross estate that the IRS counts.
• The surviving spouse is relatively young or in good health and likely to accumulate additional assets over their remaining lifetime.
• The estate includes significant life insurance. Life insurance death benefits count toward the gross estate at full face value. A $2 million term policy plus $3 million in other assets is already a $5 million estate — in a surviving spouse situation where their own assets may already be substantial.
• The surviving spouse may receive substantial inheritances in their own lifetime. Inherited assets can push a previously modest estate above the threshold by the second death.

Who Probably Does Not Need the Portability Election

The portability election is unlikely to produce significant benefit if:

• The combined net worth of both spouses — now and projected forward — is substantially under $10 million with no realistic path to exceeding the threshold
• The decedent was not married (portability applies only to surviving spouses)
• The estate is structured through irrevocable trusts that already shelter assets from the surviving spouse's taxable estate (AB trust structures accomplish similar goals through different means)

Even if you are in the "probably not needed" category, consider: Form 706 preparation for a portability election on a non-taxable estate typically costs $1,000–$2,500 with a CPA. The cost of not filing — if the surviving spouse's estate does end up above the threshold — is a tax rate starting at 18% on amounts above the exemption. For most New Hampshire families, that math strongly favors filing.

The Critical Deadline: 9 Months

The portability election must be made on a timely filed Form 706. The deadline is 9 months from the date of death, with a possible 6-month extension (filing Form 4768 by the original 9-month deadline). That means the total window, with extension, is 15 months.

This deadline runs whether or not you think the estate is taxable. Many executors of non-taxable estates simply do not open Form 706 because they believe it has nothing to do with them — and by the time someone advises them to consider portability, the deadline has passed.

Late portability elections: IRS Revenue Procedure 2022-32 provides a simplified procedure for certain estates to make a late portability election if:

• The estate was not required to file Form 706 (i.e., non-taxable)
• The election is made within 5 years of the decedent's death

This provides a safety net for executors who miss the original deadline. But relying on it means additional complexity, professional fees, and the risk that the IRS does not accept the late election in all cases. Filing on time is significantly simpler.

What Form 706 Involves for a Non-Taxable NH Estate

For a portability-only filing on a non-taxable estate, Form 706 is primarily a valuation exercise:

1. Identify and value all gross estate assets. This includes everything the federal estate tax would count: real estate at fair market value, checking and savings accounts, brokerage accounts at date-of-death values, life insurance proceeds (even if paid directly to beneficiaries), retirement account balances, business interests, and jointly held property.

2. List allowable deductions. Funeral expenses, debts owed by the deceased, and certain administrative expenses reduce the taxable estate (though for a portability-only filing, reducing the taxable estate is not the primary goal — calculating the DSUE amount is).

3. Calculate the DSUE amount. The DSUE is the unused portion of the decedent's applicable exclusion amount — essentially the $15 million 2026 exemption minus any taxable gifts made during the decedent's lifetime.

4. Make the portability election. By completing and timely filing Form 706, the executor is automatically making the portability election — no separate form or election statement is required.

5. Provide the completed Form 706 to the surviving spouse. The surviving spouse will need this document to claim the DSUE on their own estate tax return when they die. Keep it permanently — it is an irreplaceable document.

New Hampshire Context: Why This Is Often Overlooked

New Hampshire's complete absence of state estate and inheritance taxes leads many executors — and even some local professionals — to conclude that estate tax planning is simply not a concern. For most NH estates, this is correct in the immediate term: no state estate tax owed, federal estate tax owed only above $15 million, and the whole administration moves forward without Form 706 ever being opened.

The problem emerges at the second death. New Hampshire residents who have benefited from decades of no state income tax on wages or capital gains, no state estate tax, and no inheritance tax may have accumulated wealth that seemed modest in annual terms but compounds into a substantial estate over time. Appreciated White Mountains vacation properties, lakefront homes in the Lakes Region, decades-long investment portfolios — these assets can produce combined estate values at the surviving spouse's death that nobody anticipated at the first death.

The portability election is the inexpensive insurance policy against that outcome. At the time of the first death, the cost is one Form 706 preparation. At the time of the second death, the benefit can be up to $15 million in additional federal estate tax shelter.

The New Hampshire Final Tax and Estate Tax Guide includes a Portability Decision Worksheet designed to help executors and surviving spouses evaluate whether the portability election makes sense for their specific situation — covering the combined estate calculation, the deadline analysis, and the interaction between portability and existing trust structures.

Comparison: Filing Form 706 vs. Skipping It

FAQ

Does New Hampshire impose any state estate tax that affects the portability analysis? No. New Hampshire has no state estate tax and no inheritance tax. The portability election is a federal concept — it relates only to the federal estate tax. The analysis is entirely about whether the combined estate of both spouses might ever exceed the federal exemption ($15 million per individual in 2026), and whether sheltering the first spouse's unused exemption is worth the cost of filing Form 706.

What counts toward the "gross estate" for Form 706 portability purposes? The federal gross estate includes everything of value owned or controlled by the decedent: probate assets (bank accounts, investment accounts, real estate titled solely in the decedent's name), jointly held assets (the decedent's fractional share of jointly owned property), retirement account balances, life insurance proceeds (if the decedent owned the policy), and assets in a revocable living trust. This is broader than probate assets alone — many NH residents are surprised to learn that their IRAs, jointly held home, and life insurance all count.

We have a living trust. Does that eliminate the need for portability? Not necessarily. Revocable living trusts are included in the gross estate and do not independently shelter assets from estate tax. AB trust structures (also called "bypass" or "credit shelter" trusts) accomplish goals similar to portability but through different mechanics — they are typically set up before death as part of estate planning. If the decedent had an AB trust, consult an estate attorney or CPA before concluding that portability is unnecessary, because the interaction between existing trust structures and portability can affect the optimal strategy.

Can the surviving spouse use the DSUE immediately, or only at their death? The surviving spouse can use the DSUE during their lifetime for gift tax purposes, as well as at death for estate tax purposes. The DSUE is available for taxable gifts made by the surviving spouse while alive — which can be relevant for families doing active estate planning after the first death.

If the estate attorney handles the portability election, do I still need the guide? The guide and an estate attorney serve complementary roles. The guide explains NH-specific estate tax obligations in plain English so you understand the full picture — including the RETT, the Medicaid clearance requirement, the I&D Tax repeal, and the Form 1041 threshold. An estate attorney handles legal strategy and return preparation. Many executors use the guide to understand what questions to ask and which decisions matter before their first attorney meeting, then engage the attorney for the portability filing specifically.

See more New Hampshire guides →