Spousal Lifetime Access Trusts head into 2026 with a tailwind few estate planners projected three years ago. The One Big Beautiful Bill Act, signed July 4, 2025, made the federal estate, gift, and generation-skipping transfer tax exemption permanent at $15 million per individual and $30 million per married couple, effective January 1, 2026. Fidelity Investments, Charles Schwab, and Commerce Trust each refreshed their SLAT guidance in Q1 to reflect the new math: with no sunset clause, married couples can shift up to $30 million out of their taxable estate while one spouse keeps economic access through the other, locking future appreciation outside the gross estate.
Key takeaways
- OBBBA set the federal estate, gift, and GST tax exemption to $15 million per person / $30 million per couple on January 1, 2026, with no sunset (indexed for inflation from 2027).
- A SLAT is an irrevocable trust where one spouse gifts assets for the benefit of the other, removing principal from the donor’s gross estate while preserving indirect economic access.
- The reciprocal trust doctrine remains the single biggest planning trap: two SLATs that mirror each other will be collapsed by the IRS and pulled back into both estates.
- Assets transferred to a SLAT do not receive a step-up in cost basis at the grantor’s death, so highly appreciated low-basis assets are often the wrong fuel.
- South Dakota ($500+ billion in trust assets) and Nevada remain the preferred situs jurisdictions thanks to no income tax, perpetual dynasty rules, and 2-year fraudulent-transfer limits on Domestic Asset Protection Trusts.
What Changed for Estate Planners on January 1, 2026
The pre-OBBBA world ran on a clock. The 2017 Tax Cuts and Jobs Act doubled the federal exemption to roughly $13.99 million per person for 2025, but the law contained a sunset that would have reverted the exemption to $5 million (indexed) on January 1, 2026. Wealthy clients spent most of 2024 and 2025 doing what the planning community called “use-it-or-lose-it” gifting, often through SLATs, to lock in exemption before it disappeared.
OBBBA removed the cliff. The exemption is now permanent at $15 million per individual, indexed for inflation starting in 2027. The Tax Adviser, in a March 2026 estate planning review, noted that the change reframes SLATs from a defensive last-minute play into a long-horizon wealth-transfer instrument.
The number that matters for advisors is the spread. A married couple worth $25 million in 2024 might have rushed through a single SLAT to use one $13.99 million exemption before the sunset. The same couple in 2026 has $30 million of combined exemption against the same $25 million estate. The planning question shifts from “how much can we move out before the law changes” to “how do we structure the transfer for income, control, and basis trade-offs.”
Why Are SLATs Surging in the Post-OBBBA Environment?
Three factors explain the renewed interest, according to guidance from Fidelity and Commerce Trust:
Couples can now stack two exemptions. Before OBBBA, a single SLAT used one spouse’s exemption while the other spouse retained access. Splitting gifts between two SLATs (one from each spouse) was theoretically possible but constrained by the looming sunset. With $30 million permanent and indexed, two-SLAT structures become a baseline option for couples in the $10 million to $40 million range.
Appreciation moves out of the estate. Schwab’s 2026 SLAT note makes the point bluntly: a $10 million gift to a SLAT today that grows to $25 million over 15 years removes the entire $25 million from the donor spouse’s gross estate. The forgone appreciation outside the estate is often a larger tax saving than the exemption itself.
Permanence improves trustee planning. Trustees can now design discretionary distribution standards, accumulation rules, and investment policies on a multi-decade horizon rather than racing a sunset. Wickersham & Bowers, in its 2026 SLAT memo, flagged this as the single biggest structural change for trust departments at private banks.
The flow is visible in the data. South Dakota trust companies, which dominate the dynasty-trust market, hold over $500 billion in assets according to the South Dakota Division of Banking. The state ranked first in trust-jurisdiction rankings for the ninth consecutive year and has captured a disproportionate share of post-OBBBA SLAT business because of its perpetual-trust rule, no state income tax on trust income, and short fraudulent-transfer limit.
The Reciprocal Trust Doctrine: Where Most Plans Fail
The textbook SLAT misstep has not changed. If both spouses create SLATs for each other that are too similar in terms, trustees, beneficiaries, and distribution standards, the IRS applies the reciprocal trust doctrine and treats both trusts as if each spouse created the trust for their own benefit. The result is that both trusts get pulled back into both estates, defeating the entire structure.
Commerce Trust’s 2026 practitioner guide lists the variables planners should differentiate between the two trusts:
- Timing. Stagger the funding by at least 6 to 12 months. Fund Spouse A’s SLAT in January, Spouse B’s in July or the following year.
- Asset composition. Use distinct assets. One trust holds operating-company stock, the other holds marketable securities. One holds real estate, the other holds private equity interests.
- Beneficiary classes. Vary the beneficiary list. One trust includes only the spouse and adult children; the other includes the spouse, children, and a charitable remainder beneficiary.
- Distribution standards. One trust uses HEMS (health, education, maintenance, support). The other uses a broader independent-trustee discretionary standard with a Crummey power.
- Trustees. Use different individual or corporate trustees. A South Dakota trust company on one, a Nevada trust company on the other.
Fiduciary Trust’s analysis adds a fifth variable that often gets overlooked: the donor spouse’s economic dependence on the beneficiary spouse. If the donor relies on distributions to the beneficiary spouse for joint household expenses, the IRS can argue the donor retained enjoyment of trust assets under Section 2036, regardless of how well the reciprocal doctrine is sidestepped.
What Do Advisors and Clients Lose With a SLAT?
The SLAT is not free of trade-offs, and 2026 planning conversations need to surface three losses explicitly.
Loss of step-up in basis. Assets contributed to a SLAT receive carry-over basis, not the fair-market-value step-up that would occur if the asset stayed in the gross estate until the grantor’s death. For a client with $5 million of low-basis stock that has a $500,000 cost basis, transferring the stock to a SLAT permanently locks in the $4.5 million unrealized gain inside the trust. When the trust eventually sells the stock, it owes capital gains tax on the full $4.5 million plus subsequent appreciation. Mercer Advisors, in its 2026 estate tax memo, flagged this as the most frequent post-OBBBA misjudgment: clients with appreciated low-basis assets often get better after-tax outcomes by holding the asset, taking the step-up at death, and using portability to shelter the $30 million combined exemption.
Loss of economic control. The donor spouse no longer owns the asset. Distributions are at the trustee’s discretion within the trust terms, even if the trustee is the beneficiary spouse acting under an ascertainable HEMS standard. If the marriage ends in divorce, the donor spouse has no claim on the assets in the trust. If the beneficiary spouse dies first, the donor’s indirect access can disappear depending on the remainder structure.
Loss of simplicity. A SLAT requires annual trust accounting, separate trust tax returns (Form 1041), formal trustee distributions, and arms-length recordkeeping. The cost runs $5,000 to $20,000 per year for compliance and trustee fees on a moderately funded trust, which compounds over a 30- or 40-year horizon.
South Dakota vs Nevada: The Situs Decision
OBBBA reshuffled situs decisions because the GST exemption is now durable enough to support multigenerational dynasty trusts without amendment risk. South Dakota and Nevada remain the two dominant choices, with Delaware in third place.
South Dakota eliminated its rule against perpetuities in 1983 and allows trusts to last indefinitely. The state has no income tax, no capital gains tax on trust income, no premium tax on private-placement life insurance held inside trusts, and a 2-year statute of limitations on fraudulent-transfer claims for Domestic Asset Protection Trusts. The state ranks first in trust assets and trust-jurisdiction rankings.
Nevada allows trusts to last up to 365 years (long enough for most practical dynasty planning), has no income tax, allows directed trusts that separate investment and distribution decisions, and offers a 2-year fraudulent-transfer limit. Stuart Green Law’s 2026 comparison noted that Nevada’s slightly stronger creditor-protection statutes can be preferable for clients in litigation-prone professions, while South Dakota’s perpetual rule wins for clients focused on multigenerational dynasty planning.
For a SLAT specifically, the perpetuity rule matters less in the first generation and more if the trust is designed to roll into a dynasty trust after the beneficiary spouse’s death. Advisors increasingly draft SLATs with optional dynasty-trust provisions that activate at the beneficiary’s death, using the donor’s GST exemption to keep assets out of the gross estate of every subsequent generation.
What to Watch in the Second Half of 2026
Three signals worth monitoring through year-end:
IRS guidance on OBBBA portability mechanics. The portability election remains unchanged in statute, but several practitioner groups have asked Treasury to clarify how surviving spouses elect portability when the deceased spouse used SLAT structures that consumed part of the exemption. Expect proposed regulations by Q4 2026.
State-level dynasty trust competition. Wyoming and Tennessee both updated their trust statutes in early 2026 to compete with South Dakota and Nevada on perpetuity duration and DAPT seasoning periods. Trust assets are migratable, and the situs competition is likely to intensify as OBBBA’s permanence attracts more multigenerational planning flow.
Carried-interest and PIK note SLAT funding. Private equity general partners are increasingly funding SLATs with carried-interest profits interests and payment-in-kind notes, capturing the low entry valuation while moving future appreciation out of the estate. Treasury has signaled interest in revisiting the valuation methodology for carried-interest gifts, and any guidance would directly affect SLAT funding strategies for this client segment.
Questions Advisors Should Bring to Their Estate Counsel Before Year-End
Three concrete questions for the next client review:
- What is the optimal funding asset mix for a SLAT in this client’s portfolio? Specifically, which assets have appreciation potential that justifies forgoing the step-up, and which assets should be held for the step-up at death and sheltered through portability?
- Has the reciprocal trust doctrine been stress-tested? If both spouses create SLATs, list the five reciprocal-doctrine variables (timing, asset composition, beneficiaries, distribution standards, trustees) and confirm that each trust differs on at least three.
- Does the trust document include an optional dynasty-trust conversion at the beneficiary spouse’s death? With OBBBA’s GST exemption now permanent, omitting this provision wastes one of the most valuable transfer-tax shelters available.
For advisors and clients re-examining estate strategy under the new permanent exemption, the related 2026 OBBBA analysis on the $15 million estate tax exemption planning framework covers the broader portability and basis-step-up trade-offs, while the Roth conversion strategy under OBBBA’s permanent rates addresses the income-tax side of the same multigenerational planning equation.
As of May 2026. Tax law and trust strategies depend on individual circumstances and state law. This article is informational, not legal or tax advice.
Associate Editor of financial news at Market signals where he writes and edits original analysis in and around the wealth management, as well as other parts of the financial markets and economy. He has more than five years of experience editing, proofreading, and fact-checking content on current financial events and politics.
