Spousal Lifetime Access Trust (SLAT) After OBBBA: Why the $15 Million Exemption Still Demands Action in 2026

For nearly a decade, estate planners watched the calendar tick toward January 1, 2026, bracing for the Tax Cuts and Jobs Act exemption to halve overnight. Then the One Big Beautiful Bill Act, signed into law on July 4, 2025, rewrote the script. The federal gift, estate, and generation-skipping transfer (GST) tax exemption did not collapse. Instead, it stepped up to $15 million per person and $30 million per married couple, indexed for inflation starting in 2027, and the new figure was made permanent.

If your first reaction is "great, I can stop worrying about a SLAT," pause. Permanent in tax law is a relative term, the underlying mechanics that make a Spousal Lifetime Access Trust valuable have not changed, and the strategic case for funding one in 2026 may actually be stronger than it was during the pre-sunset scramble. Here is what high-net-worth families need to understand about SLATs in the new exemption landscape, the planning traps that catch couples who move too fast, and the structural choices that determine whether a SLAT survives IRS scrutiny.

What a SLAT Actually Does

A Spousal Lifetime Access Trust is an irrevocable trust funded by one spouse (the donor) for the benefit of the other (the beneficiary spouse), often along with children, grandchildren, or other descendants. Once the trust is funded, the donor spouse uses some or all of their lifetime gift exemption to cover the transfer, and the trust assets, including all future appreciation, sit outside both spouses' taxable estates.

Three properties make the structure powerful:

1. Estate freeze. The transferred value, plus every dollar of growth that follows, escapes the 40 percent federal estate tax that would otherwise hit the donor's estate above the exemption.
2. Indirect access. Because the donor's spouse is a discretionary beneficiary, the family can still tap the trust for support during the marriage. That access is what differentiates a SLAT from an outright gift to children, where the donor permanently severs all benefit.
3. GST leverage. Allocating GST exemption to the trust lets assets pass to grandchildren and beyond without a second layer of transfer tax. Multi-generational compounding is where SLATs do their heaviest lifting.

The trust is typically structured as a grantor trust, meaning the donor pays the income tax on trust earnings personally. That is a feature, not a bug. Every dollar of tax the donor pays effectively transfers additional wealth to the trust beneficiaries free of gift tax.

How OBBBA Changed the Calculus

Before July 2025, the planning world was racing the clock. The TCJA exemption was scheduled to drop from roughly $13.99 million per person in 2025 to about $7 million on January 1, 2026, depending on inflation adjustments. Couples with $20 million to $40 million in net worth faced a "use it or lose it" decision: either gift the high exemption away before the sunset or watch a chunk of it disappear forever.

OBBBA replaced that cliff with a $15 million per person exemption ($30 million per couple) effective January 1, 2026, indexed annually thereafter. Headlines treated this as an all-clear. The reality is more nuanced.

The case for funding a SLAT anyway

• "Permanent" is political. OBBBA made the $15 million exemption permanent in the same way TCJA was supposedly permanent in 2017. A future Congress with different priorities can reduce the figure with a single statute, and there is no constitutional protection against it. Wealthy taxpayers who locked in the higher TCJA exemption with anti-clawback protection are sitting comfortably; the next round of taxpayers may not get the same window.
• Compounding is unforgiving. Every year an asset stays in your estate is another year of growth taxed at 40 percent on the back end. A $5 million gift today that doubles over twenty years removes $10 million from the taxable estate. Waiting five years to fund the same trust removes only the post-2031 appreciation.
• State estate taxes have not moved. Twelve states plus DC impose their own estate tax with much lower thresholds, sometimes as low as $1 million in Massachusetts and Oregon. A SLAT removes assets from both the federal and the state taxable estate.
• Asset protection. Properly drafted SLATs sit beyond the reach of future creditors and divorce claims against the beneficiary spouse, depending on state law. That benefit exists regardless of where the exemption sits.
• Anti-clawback rule still applies. Treasury regulations confirm that gifts made under a higher exemption are not later subject to estate tax if the exemption falls. Lock in today's number and you have it.

The strategic question is no longer "do we beat the sunset?" It is "do we use 2026 to compress a generation of growth out of our estate?"

Who Should Consider a SLAT

A SLAT only earns its complexity when the family has a real estate tax problem. As a rough screen:

• Combined net worth above $30 million. Couples below the joint exemption have nothing to remove. Below $30 million, simpler tools (annual exclusion gifting, 529 plans, Roth conversions) usually deliver better risk-adjusted value.
• Assets with significant growth potential. Founder stock, pre-IPO equity, real estate in appreciating markets, and concentrated positions in early-stage businesses are ideal SLAT fuel. Mature, slow-growing assets produce less estate freeze upside.
• Stable marriage. Divorce is the silent killer of SLAT planning. If the marriage ends, the donor spouse loses indirect access through the beneficiary spouse, and depending on the trust language, the donor may be looking at trust assets they can no longer reach.
• Adequate retained wealth. Never fund a SLAT with assets you might need for your own retirement. The standard planner's rule is that the donor spouse should keep at least enough outside the trust to fund expected lifestyle for life with margin.

If you live in a state with its own estate tax, the threshold drops. A New York couple with $8 million in real estate might still benefit from a SLAT even though they are well under the federal exemption.

Single SLAT vs. Dual SLATs

Couples often want to set up two SLATs, one funded by each spouse for the benefit of the other, so that both halves of the marital exemption get used. That is where most of the planning danger lives.

The IRS challenges identical or near-identical mirror trusts under the reciprocal trust doctrine, originating in United States v. Estate of Grace (1969). If two trusts leave the spouses in approximately the same economic position they would have been in had each created a trust for themselves, the IRS can "uncross" the trusts and pull the assets back into both estates under Internal Revenue Code sections 2036 and 2038. The result is a complete failure of the planning, often discovered only at the death of the second spouse, when the estate tax bill arrives.

There is no bright-line test, but courts and the IRS look at the substance of the trusts side by side. Mirror image trusts signed on the same day with identical assets, identical trustees, identical beneficiaries, and identical distribution standards are highly vulnerable.

Building meaningful differences

Practitioners who fund dual SLATs typically vary as many of these dimensions as they reasonably can:

• Beneficiaries. One trust might benefit the spouse, children, and grandchildren; the other might benefit the spouse and children only, or include charity. Adding a sibling, a parent, or a class of nieces and nephews to one but not the other helps.
• Distribution standards. One SLAT might use the strict ascertainable HEMS standard (health, education, maintenance, support); the other might add discretionary distributions for "best interest" subject to an independent trustee, or limit the spouse to distributions under HEMS only.
• Trustees. Different individual trustees, or one trust with a corporate trustee and the other with a non-spouse family member as trustee.
• Powers of appointment. Granting the beneficiary spouse a limited power of appointment in one trust but not the other, or framing those powers with different scopes, materially distinguishes the two.
• Funding assets. One SLAT might hold marketable securities; the other might hold real estate, closely held business interests, or insurance. Identical brokerage accounts on both sides is a red flag.
• Timing. Separate the funding by a meaningful interval. Federal cases suggest fifteen days is likely insufficient. Several months, or splitting funding across calendar years, is safer.
• Investment policy. Different trustees making genuinely different investment decisions reinforce that the trusts are not running in lockstep.

The goal is not to make the trusts unrecognizable to one another. It is to ensure that, looked at as a whole, the spouses are not left in the same economic position they would occupy if each had created a trust for themselves.

Funding Strategy: What Belongs in a SLAT

Once the structure is decided, asset selection drives long-term outcomes.

Best candidates:

• Pre-IPO equity, founder shares, and concentrated stock with significant runway
• Investment real estate, especially in appreciating markets or with strong cash flow
• Interests in family businesses, particularly where minority interest valuation discounts apply
• Carried interest and partnership interests with appreciation potential
• Hard-to-value assets where qualified appraisals support discounts of 20 to 40 percent

Generally avoid:

• Personal residences (control issues and possible inclusion under section 2036 if the donor lives there)
• Retirement accounts (transfer triggers immediate income tax)
• Assets the donor expects to need for living expenses
• Highly liquid cash positions with no growth narrative

Under-discussed: valuation discounts. Transferring minority interests in family LLCs or partnerships often qualifies for combined lack of control and lack of marketability discounts. A $10 million underlying asset can sometimes be transferred at a $6 million to $7 million reported gift value, stretching exemption further. The discount must be supported by a defensible appraisal; aggressive positions invite IRS challenge.

The Tax Mechanics Founders Most Often Miss

A few details routinely surprise donors who learned about SLATs from a one-page summary.

Gift tax return required. Any transfer to a SLAT that uses lifetime exemption must be reported on Form 709 in the year of the gift, even though no tax is due. Filing the return starts the three-year statute of limitations on IRS challenges to the gift, so adequate disclosure is essential. Skipping the return leaves the gift exposed indefinitely.

Grantor trust status. Most SLATs are intentionally drafted as grantor trusts so the donor pays the income tax on trust earnings. This is a wealth transfer accelerator: the trust grows untaxed inside, and every dollar of tax the donor pays is effectively a gift-tax-free transfer. The trade-off is cash flow planning. Founders with concentrated low-basis stock should model the tax impact carefully before pulling the trigger.

No step-up at death. Because SLAT assets are outside the donor's estate, they do not receive a basis step-up under section 1014 when the donor dies. Heirs inherit the donor's original basis. For low-basis assets that beneficiaries plan to hold long-term, that is fine. For assets the family expects to liquidate soon after death, a SLAT may be the wrong vehicle. Many families use a hybrid approach, leaving the lowest-basis assets in the estate to capture step-up and pushing higher-basis growth assets into the SLAT.

Loans and exchanges between spouses and the SLAT. Properly structured loans from the trust to the donor, or substitution of assets between donor and trust under a swap power, can refresh basis or move appreciated assets back into the donor's estate before death. These post-funding maneuvers are legal and routine but require care to avoid blowing up grantor status or triggering deemed gifts.

Common Mistakes That Unwind the Planning

The technical paperwork rarely fails. The behavioral discipline is what creates problems.

• Treating the SLAT as a joint piggy bank. Distributions to the beneficiary spouse must follow the trust standard. If the donor and beneficiary spouse pool everything and pay shared expenses out of trust assets, the IRS may argue that the donor retained a beneficial interest, pulling assets back under section 2036.
• Naming both spouses as trustees. The donor spouse should never be a trustee with discretion to make distributions to the beneficiary spouse. That control ends the planning under section 2036.
• Same trust company, same documents, same date. This is the reciprocal trust doctrine alarm bell.
• No trust accounting. Trustees who do not maintain separate books, file fiduciary income tax returns, or document distributions invite both IRS and beneficiary challenges.
• Funding with assets the donor still operates. Active business interests where the donor retains effective control after the gift can be included in the donor's estate under section 2036(a)(2).
• Missing the marriage risk. SLATs do not survive divorce gracefully. Pre-funding marital agreements addressing what happens to trust access if the marriage ends are increasingly standard for high-stakes funding.

Cost and Timeline

Expect SLAT planning to cost between $15,000 and $50,000 in legal fees for couples implementing dual structures, plus appraisal costs for non-marketable assets ranging from $5,000 to $25,000 per appraisal. Annual administrative costs run from $5,000 to $25,000 depending on trustee fees, accounting complexity, and asset management.

Implementation typically takes three to six months from initial planning to fully funded trust. Rushed funding at calendar year-end is one of the highest-risk patterns; the IRS regularly succeeds against December 30 SLAT funding that lacks paper trail and appraisal support.

Why Records Beat Theory at Audit

Almost every successful IRS challenge to an estate planning structure begins the same way: missing or inconsistent records. The trust paperwork looks good, but the day-to-day administration tells a different story. Distributions that should have flowed through the trustee went straight from a personal account. Tax returns reported the trust's income on the donor's individual return for years before anyone noticed. Loans between the donor and the trust never made it into a written note.

Disciplined record-keeping is not optional once a SLAT is funded. Every distribution, every loan, every basis adjustment, every income tax payment by the donor needs to be tracked separately for the trust and reconciled annually. Tax preparers, trustees, and accountants all rely on those records to produce defensible returns. Families that treat trust accounting as an afterthought routinely discover the gap during audit, when reconstruction is expensive and exposure is unbounded.

Keep Your Wealth Transfer Records Audit-Ready

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