Estate Tax Exemption Sunset 2026: The TCJA Cliff and the Closing 'Use It or Lose It' Gifting Window

If the sunset worries you, start with this one structural idea

For the past several years, no word has dominated estate planning conversations more than “sunset.” The mechanics are actually simple. The 2017 Tax Cuts and Jobs Act temporarily roughly doubled the federal unified exemption, and that increase was written to expire at the end of 2025. Without new legislation, the exemption is scheduled to revert to its pre-2018 baseline in 2026. Roughly half.

Here is my blunt take. This sunset is not an event where the rate goes up. It is an event where the amount you can shield goes down. And exemption is a use-it-or-lose-it right in the most literal sense. Only people who actually move assets out of their estate while the higher exemption is alive lock in the benefit. People who do nothing simply forfeit the difference the moment the number falls.

One caveat has to sit alongside all of this. Transfer tax law is politically volatile. Congress could extend the higher exemption, make it permanent, or let it revert on schedule. This article does not assert that any specific bill has been enacted. The figures used here are illustrative, and the binding number for any given year must be confirmed with a professional. On that footing, the goal is to understand the logic of the gifting window that the sunset structure creates.

👉 If you are weighing the timing of an equity event, the ISO AMT guide 2026 walks through the same kind of timing-tax tradeoff.

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What is the unified exemption, and why does it get cut in half?

A defining feature of the US system is that estate and gift taxes share a single unified credit. Whether you give during life or transfer at death, both draw from the same lifetime pool. Give a lot away now and the exemption remaining at death shrinks by the same amount.

For 2025, the per-person unified exemption sat near 13.99 million dollars. A married couple that fully uses each spouse’s amount approaches roughly 28 million dollars combined. If the sunset applies as scheduled, that per-person figure drops to the old five-million baseline plus inflation, landing somewhere in the seven-million range.

Item	Higher-exemption regime (e.g., 2025)	Illustrative post-sunset regime	Change
Per-person unified exemption	~13.99 million	~7-million range	About half
Married couple combined	~28 million	~14-million range	About half
Top rate on excess	40% bracket	40% bracket	Unchanged
GST exemption	Tied to unified exemption	Falls with it	Halved

A common misread hides here. The top rate stays at 40 percent; what changes is how much passes free of tax. Cutting the per-person exemption by roughly seven million dollars means a couple loses shelter on about 14 million dollars of value. Apply the top rate and you are looking at a potential tax difference measured in the millions. That is why the sunset is described as quiet but large.

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Why are 2025 and 2026 a genuine ‘use it or lose it’ window?

The exemption’s most counterintuitive feature is that gifts are treated as coming “off the bottom.” When you make a taxable gift, it uses up the lower part of your exemption first. Because of that rule, a person who gifts only up to the lower amount before the sunset locks in essentially nothing. The extra benefit is secured only by actually gifting into the band between the higher and lower exemption.

Work through an example. Suppose a couple gifts seven million dollars each, 14 million total. If the post-sunset exemption is in the 14-million-combined range, that gift is treated as sitting inside the lower exemption and produces little additional savings. Now suppose the couple instead gifts close to 28 million and drains the high exemption. The band between the two amounts is permanently removed from the taxable estate.

That band is the window. To benefit, you must transfer more than the lower exemption while the higher exemption is still in effect. Use only half and half evaporates. That asymmetry is the core reason wealthy families feel the deadline pressure.

But the deadline itself depends on legislation. If Congress extends or makes the exemption permanent, the window does not close. If it reverts on schedule, the window really does shut. Rather than acting as if a specific future is certain, the wiser move is to design for both outcomes.

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How do the annual exclusion, lifetime exemption, portability, and GST fit together?

Before discussing sunset moves, it helps to separate four distinct tools. Blurring them produces bad plans.

Annual exclusion. You can give each recipient a set amount per year (around 19,000 dollars in 2025) without touching your unified exemption. Give to three children and you multiply it; split gifts with a spouse and you double it again. It resets annually and is the workhorse for moving wealth quietly.

Lifetime gift exemption, which equals the estate exemption. Gifts above the annual exclusion draw down the unified pool. As noted, lifetime gifts and transfers at death share this one bucket.

Portability. A surviving spouse can inherit the deceased spouse’s unused exclusion, but it is not automatic; it must be elected on a Form 706 estate tax return, and critically, it does not carry over the GST exemption.

Generation-skipping transfer (GST) tax. A separate tax on transfers that skip a generation, such as gifts to grandchildren. The GST exemption tracks the unified exemption but must be allocated and tracked separately, which is central to building a long-term dynasty trust.

Tool	Nature	Resets	Sunset impact	Watch out for
Annual exclusion	Small recurring gifts	Yearly	Not directly cut	Excess draws the exemption
Lifetime exemption	Large transfers	Depletes	Halved	Shared with estate exemption
Portability	Inherit unused amount	—	Less to port if base falls	No GST carryover, must elect
GST exemption	Skip-generation	Allocated	Falls with it	Track and allocate separately

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When are a SLAT and an irrevocable trust the right answer?

The advice to “use the high exemption now” stalls most people at one fear: once you give it away, you cannot touch it again. The moment assets go into an irrevocable trust they leave your estate, but they also leave your control. The SLAT was designed to soften exactly that barrier.

Spousal Lifetime Access Trust. One spouse funds an irrevocable trust naming the other spouse as a beneficiary. The assets leave the donor’s estate and burn the high exemption, yet the beneficiary spouse can receive distributions if needed, so the household retains some access. It is the compromise of “we gave it away, but as a couple we are not entirely cut off.”

Two traps demand attention. First, if the beneficiary spouse dies or the couple divorces, that access path is severed. Second, if spouses create nearly identical SLATs for each other, the IRS can apply the reciprocal trust doctrine to unwind both trusts and erase the estate exclusion. That is why two SLATs must be deliberately different in timing, funded assets, beneficiary terms, and trust provisions.

Plain irrevocable trusts and outright gifts. You can also fund a trust for children or grandchildren directly, skipping the spouse. Access is lower, but there is no reciprocal-trust risk, and structured as a generation-skipping trust it can pre-allocate GST exemption so assets compound for decades without additional transfer tax.

The point is not the elegance of the tool but how much you can permanently part with. Chasing exemption use without liquidity headroom endangers your own retirement.

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Which assets should you gift, and how much?

The biggest lever in choosing gift assets is moving future appreciation out early. Gift an asset that is low now but expected to climb, and only today’s value draws down your exemption while all subsequent growth compounds outside the estate. Growth stocks, early-stage business interests, and developable real estate are classic candidates.

The essential counterweight is the step-up in basis. Assets passing at death get their cost basis reset to date-of-death value, effectively wiping out prior appreciation for income tax purposes. A lifetime gift, by contrast, carries over the donor’s low basis, so the recipient faces a large capital gains bill on a later sale. In other words, saving estate tax can raise income tax.

The rough dividing line is this. If your estate clearly exceeds the exemption and sits solidly in the 40 percent bracket, moving appreciating assets out often wins even at the cost of the step-up. If your estate hovers near the exemption, a hasty gift can lose the step-up while the estate tax was never going to apply, which is the worst of both worlds.

Valuation discounts are another powerful tool. Interests lacking control or marketability, such as a minority stake in a family limited partnership or a closely held business, can be gifted at a reduced appraised value using lack-of-control and lack-of-marketability discounts. The same exemption moves more economic value. But this is a favorite IRS battleground, so an independent appraisal plus genuine business substance and operating records are mandatory. An entity that looks like an empty tax shell invites the discount being disallowed.

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Why do state estate taxes need their own attention?

Looking only at the federal number is a common blind spot. Several states levy their own estate or inheritance tax separate from the federal system, and their exemptions are frequently much lower. You can have ample federal headroom and still owe a meaningful tax based on where you live.

State estate and inheritance taxes sound similar but hit different parties. An estate tax is settled by the estate on the total left behind; an inheritance tax is paid by each recipient based on relationship and amount. Some states have neither, some have one, and a few situations trigger both.

In practice, changing your domicile in retirement can itself be a serious planning move. But a domicile change is tested on substance, so it means genuinely relocating your center of life, not merely switching a mailing address. Fixating on the federal sunset while ignoring state exposure produces the irony of the real bill arriving from the state.

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What are the common mistakes and urgency traps?

The greatest danger a deadline creates is not the tax itself; it is moving fast and moving wrong. Here are the traps that recur in practice.

Over-gifting into illiquidity. Chasing a fully used exemption by pushing assets you actually need into an irrevocable trust is irreversible. You save tax and then find your own life pinched. The first rule of gifting is that it must be money you can live without.

Ignoring the lost step-up. As covered, rushing to gift appreciated assets when estate tax was never a real threat only inflates income tax.

Reciprocal trust doctrine. Mirror-image spousal SLATs can be unwound, erasing the exclusion.

Deadline-driven sloppy paperwork. Rushed appraisals, trust documents, and transfer records become targets later. For valuation discounts especially, document quality is the entire defense.

Going all-in against legislative risk. Making sweeping, irreversible decisions on the assumption the exemption will revert, when it might be extended or made permanent, is its own hazard.

Mistake	What you lose	Mitigation
Over-gifting	Retirement liquidity	Gift only spare assets; pair with a SLAT
Ignoring step-up	Future capital gains tax	Weigh estate size before gifting appreciated assets
Mirror SLATs	Estate exclusion	Differentiate terms, timing, and assets
Sloppy documents	Appraisal and trust defense	Independent appraisals, start early, document
Legislative all-in	Flexibility	Staged, conditional gifting

👉 If you are a high-earning self-employed person looking to maximize pre-tax savings elsewhere, the small-business defined benefit plan guide 2026 covers a very different tax lever.

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What should you check right now: a practical checklist

The takeaway is that sunset planning is not “gift the maximum no matter what.” It is “transfer as much as is genuinely worth locking in for your situation, knowing the decision is irreversible, and execute with proper documentation.”

Start by tallying your net worth honestly and asking whether it exceeds the exemption at all. If not, the sunset is not an urgent issue for you. If it does, ask whether you have both the means and the willingness to move assets into the band between the higher and lower exemption. Then work through liquidity backstops (whether a SLAT fits), the basis-step-up tradeoff by asset, which assets support valuation discounts, and your state-level exposure. Finally, build a conditional plan across legislative scenarios so you have few regrets whether the exemption is extended or reverts.

Above all, every one of these judgments turns entirely on your specific asset mix, family situation, and state of residence. Have the plan reviewed by an estate attorney and a CPA. Deadline pressure is the enemy of good design. Move with urgency, but do not let urgency make you careless.

👉 Curious about the separate world of taxing investment gains? See the stock capital gains tax guide 2026.

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Further reading

• 👉 ISO AMT Guide 2026: Exercise Timing and the Tax Traps
• 👉 Small-Business Defined Benefit Plan Guide 2026: Large Pre-Tax Savings
• 👉 Stock Capital Gains Tax Guide 2026: Strategy and Practical Filing

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This article is for general informational purposes only and is not tax or legal advice. US federal and state estate and gift tax rules are frequently amended and depend on pending legislation; the exemptions and figures mentioned here are illustrative and may differ from the binding amounts that actually apply. Estate and gift planning outcomes vary widely based on your asset mix, state of residence, and family situation, so consult a qualified estate attorney and CPA before acting.