The tax benefits of a spendthrift trust come from three places: pulling assets and their future growth out of the grantor’s taxable estate, shifting investment income to beneficiaries who pay at lower rates, and locking in a generation-skipping transfer tax exemption that can carry wealth across multiple generations without another federal tax bite. Whether you actually capture those benefits depends on two structural choices made when the trust is drafted, namely whether it is irrevocable and whether it is treated as a grantor or non-grantor trust for income tax purposes.
Removing Assets From the Taxable Estate
The largest tax savings a spendthrift trust can produce come from estate tax exclusion, and this only works if the trust is irrevocable. An irrevocable trust cannot be revoked, amended, or materially changed by the grantor after it is created.1Internal Revenue Service. Abusive Trust Tax Evasion Schemes – Questions and Answers Permanence is the price of admission.
Done correctly, every dollar transferred into the trust, plus all future appreciation, is excluded from the grantor’s gross estate. A $5 million stock position that grows to $20 million by the grantor’s death drops out of the estate entirely. The federal estate tax rate on amounts above the exemption is 40%, so the savings on the appreciation alone can run into millions.
For 2026, the federal estate tax exemption is $15 million per individual, made permanent by the One, Big, Beautiful Bill Act.2Internal Revenue Service. Whats New – Estate and Gift Tax Married couples can effectively shelter $30 million. If your estate sits comfortably below those numbers, this benefit is theoretical for you. If it does not, moving appreciating assets into an irrevocable spendthrift trust while they are still relatively undervalued locks in the exclusion at today’s numbers.
The exclusion collapses if the grantor holds onto too much. Retaining enjoyment of the property or keeping the right to control who benefits from it will pull the full value of the trust back into the estate as if the transfer never happened.3Office of the Law Revision Counsel. 26 U.S. Code 2036 – Transfers With Retained Life Estate That means no living in trust-owned property rent-free, no collecting the income, no swapping beneficiaries at will. An independent trustee with no family or business relationship to the grantor is the standard safeguard.
Gift Tax on the Funding Transfer
Funding an irrevocable spendthrift trust is a completed gift. The grantor has parted with dominion and control, which triggers the gift tax rules.1Internal Revenue Service. Abusive Trust Tax Evasion Schemes – Questions and Answers In practice, the grantor applies the $15 million lifetime exemption to cover the transfer, so no gift tax is actually owed. Because the gift and estate tax exemptions are unified, exemption used during life reduces exemption available at death.
The strategic logic of gifting early is that gift tax is calculated on value at transfer, not on value at some future date. A $2 million gift of real estate that later grows to $8 million uses only $2 million of exemption. The $6 million of growth passes free of both gift and estate tax.
For ongoing contributions, the annual gift tax exclusion, which is $19,000 per recipient for 2026, can reduce the drain on the lifetime exemption.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 There is a wrinkle. Gifts to a trust are ordinarily treated as future interests, which disqualifies them from the annual exclusion. The standard fix is a Crummey withdrawal power in the trust document, giving each beneficiary a temporary right to pull out newly contributed funds. Beneficiaries almost never exercise the right, but its legal existence converts the gift into a present interest that qualifies for the $19,000 exclusion per beneficiary per year.
Generation-Skipping Transfer Tax Exemption
Spendthrift trusts designed to last across generations face one more federal tax. The generation-skipping transfer tax applies whenever wealth passes to someone two or more generations below the grantor. The rate is 40%.
Each individual has a separate GST exemption equal to the basic estate tax exclusion, which for 2026 is $15 million.5Office of the Law Revision Counsel. 26 USC 2631 – GST Exemption Allocating the exemption to the trust at funding produces a zero inclusion ratio, meaning no GST tax hits distributions or terminations at any generational level for the life of the trust. A married couple allocating both exemptions can shield $30 million from GST tax permanently. For a dynasty-style spendthrift trust meant to last for generations, allocating GST exemption at the outset is the difference between tax-free multigenerational transfer and a 40% hit every time the trust benefits a skip generation.
Grantor Trust vs. Non-Grantor Trust: Who Pays Income Tax
The other big tax lever is income tax treatment during the trust’s life. If the grantor keeps certain powers or a beneficial interest, the IRS treats the trust as a grantor trust. All dividends, interest, and capital gains flow through to the grantor’s personal return, and the trust is invisible for income tax purposes.
This sounds like a bad deal but is often the whole point. When the grantor pays the tax personally, every dollar inside the trust keeps compounding for the beneficiaries. The grantor is effectively making an additional untaxed gift each year by covering the income tax bill, and that tax payment is not treated as a separate transfer, so it does not eat into the gift tax exemption. Over decades on a substantial portfolio, this quietly moves a lot of value out of the estate.
A non-grantor trust is its own taxpayer. It files Form 1041 and reports income under a compressed bracket schedule.6Internal Revenue Service. About Form 1041, U.S. Income Tax Return for Estates and Trusts For 2026, the top 37% federal rate hits at just $16,000 of taxable income.7Internal Revenue Service. Revenue Procedure 25-32 An individual does not reach 37% until income exceeds about $626,350. Undistributed trust income gets taxed at rates that would make most people wince.
Shifting Income Through the Distribution Deduction
The compressed brackets are not a trap if the trustee uses the distribution deduction. When a non-grantor trust distributes income to beneficiaries, it deducts those distributions, and the beneficiaries report the income on their own returns at their individual rates.8Office of the Law Revision Counsel. 26 U.S. Code 661 – Deduction for Estates and Trusts Accumulating Income or Distributing Corpus A beneficiary in the 22% bracket receiving $50,000 of trust income spares the trust from paying 37% on the same amount. This is the single most important income tax lever a trustee has.
The deduction is capped at distributable net income (DNI), which is roughly the trust’s taxable income with adjustments. Capital gains allocated to trust corpus generally stay out of DNI unless the trust document or local law directs otherwise.9Office of the Law Revision Counsel. 26 U.S. Code 643 – Definitions Applicable to Subparts A, B, C, and D So a trust can usually pass through ordinary income and dividends but often ends up paying tax on its own capital gains.
Timing matters more than most trustees realize. The 65-day election lets a trustee make a distribution within the first 65 days of a new tax year and treat it as if made on the last day of the prior year.10eCFR. 26 CFR 1.663(b)-1 – Distributions in First 65 Days of Taxable Year A trustee who closes out 2025 holding more income than expected can distribute by early March 2026 and elect the distribution as a 2025 event. The election is made on that year’s Form 1041 and is irrevocable once filed. The amount eligible cannot exceed DNI for the year.
The 3.8% Surtax on Retained Earnings
Undistributed investment earnings also face the net investment income tax of 3.8%. For individuals, this surtax kicks in at $200,000 of modified adjusted gross income, or $250,000 for married couples. For trusts, the threshold matches the top income tax bracket, which for 2026 is $16,000.7Internal Revenue Service. Revenue Procedure 25-32 A non-grantor spendthrift trust retaining even modest investment income will almost certainly owe it. Combined with the 37% top bracket, retained trust income can face an effective federal rate above 40%. Another reason to distribute when the spendthrift terms allow.
The Step-Up Basis Trade-Off
Estate tax exclusion has a downside that catches many families off guard. When someone dies owning appreciated property, the tax basis normally resets to fair market value at death. Heirs can then sell without owing capital gains tax on the appreciation that occurred during the decedent’s lifetime.11Office of the Law Revision Counsel. 26 U.S. Code 1014 – Basis of Property Acquired From a Decedent
Assets in an irrevocable spendthrift trust do not get this step-up. The IRS confirmed in Revenue Ruling 2023-2 that property held in an irrevocable grantor trust and not included in the grantor’s taxable estate does not qualify for a basis adjustment at the grantor’s death. Beneficiaries inherit the grantor’s original cost basis. Stock the grantor bought for $500,000 that is now worth $5 million leaves the beneficiaries with a potential $4.5 million capital gain when they sell.
The math is a comparison. You are trading a 40% estate tax on the full value for capital gains tax (typically 20% federal plus the 3.8% NIIT) on only the appreciation. For highly appreciated assets, the estate tax savings usually wins. For assets with modest appreciation, leaving them in the estate to receive the step-up may come out ahead. A “power of substitution” clause lets the grantor swap personal assets for trust assets of equal value, which can be used to pull a low-basis asset back into the estate before death (so it gets the step-up) while replacing it with a high-basis asset that does not need one.
Where Spendthrift Protection Does Not Reach
A spendthrift clause blocks most creditors from reaching trust assets before distribution, but the exceptions matter for tax planning. Federal tax liens are the biggest. The IRS Internal Revenue Manual states that spendthrift restrictions “are not effective to remove those benefits from the reach of the federal tax lien, regardless of whether under the appropriate state law a ‘spendthrift’ trust is regarded as valid in all respects.”12Internal Revenue Service. Internal Revenue Manual 5.17.2 – Federal Tax Liens If a beneficiary owes back taxes, the IRS can reach their trust interest regardless of what the document says. Child support and alimony obligations can typically reach spendthrift distributions as well.
Protection weakens further when the grantor is also a beneficiary. A self-settled spendthrift trust faces a 10-year lookback in federal bankruptcy proceedings for transfers made with intent to hinder creditors, compared with a two-year lookback for standard third-party spendthrift trusts.13Office of the Law Revision Counsel. 11 U.S. Code 548 – Fraudulent Transfers and Obligations
State Income Tax on Trust Earnings
Federal planning gets most of the attention, but state income tax on trust earnings can quietly cut into returns. States vary widely in how they decide whether a trust owes state tax. Common factors include where the trust was created, where the trustee is located, where the trust is administered, and where the beneficiaries live. Some states use one factor, others combine several.
A trust with a professional trustee in a high-income-tax state could face state tax on all undistributed income even if the beneficiaries live in no-tax states. Other states tax trusts based only on beneficiary residency, which can produce a state tax bill even when the trustee sits in a friendly jurisdiction. The choice of trustee location and trust situs can have real dollar consequences over the life of a long-term spendthrift trust, and it is far cheaper to get right at the beginning than to fix later.