Grantor Trust Planning Strategies for High-Net-Worth Families

By Hannah Morgan | Reviewed by a CPA and estate-planning attorney prior to publication | This article covers U.S. federal tax law only. State income tax, state estate tax, and state trust law vary widely and are not addressed here.

A family that sells a $10 million stake in an operating company to a trust its own grandmother funded with $1 million nine years earlier is not doing anything exotic. It is running a transaction that the IRS blessed in 1985, using rules that have sat in the tax code since 1954 largely unchanged. The mechanics are old. The dollar amounts involved in 2026, with a $15 million federal exemption per person, are not.

The Quick Answer

Does a Grantor Trust Make Sense for You?

Before any drafting starts, run the numbers past a simple filter. Grantor trust planning tends to earn its cost when several things line up at once, not when just one does.

• Your estate exceeds, or will likely exceed, the federal exemption. For 2026 that exemption sits at $15 million per person under the permanent adjustment made by the One Big Beautiful Bill Act, so couples with a combined net worth comfortably under $30 million often get more value from simpler tools.
• You own an asset that is likely to outgrow a modest interest rate. A closely held business, a concentrated stock position, or real estate with upside is a far better candidate than a bond portfolio.
• You can afford to pay someone else’s income tax. Grantor trust status means you, not the trust, report the income on your own Form 1040. That only works if your cash flow can absorb it for years.
• You are comfortable giving up control in exchange for tax outcomes. Once assets move into an irrevocable trust, getting them back is either impossible or requires mechanisms built in ahead of time, such as a swap power.

The Grantor Trust Rules: IRC Sections 671 Through 679

Subpart E of the Internal Revenue Code, Sections 671 through 679, decides who pays income tax on a trust’s earnings. Ordinarily a trust is its own taxpayer. Under these sections, though, if the person who created the trust (or in some cases a beneficiary) retains certain powers or interests, the tax code looks straight through the trust and taxes that person on the trust’s income as if the trust did not exist for income tax purposes.

Section 675 is the workhorse provision for planners. It treats a trust as a grantor trust if the grantor holds administrative powers over trust property, and one specific power gets used constantly: the ability to reacquire trust assets by substituting property of equivalent value, sometimes called a swap power. Section 674 covers powers to control beneficial enjoyment. Section 677 covers a grantor’s right to trust income. Sections 673, 676, and 678 fill in reversionary interests, revocation powers, and situations where someone other than the grantor gets treated as the owner.

The gap between income tax ownership and estate tax ownership is the entire point. Congress wrote these sections to stop grantors from dodging income tax by shifting income to a trust taxed at lower rates. It never occurred to the drafters that estate planners would later use the same rules on purpose to keep assets in a grantor’s taxable income while pulling them out of the taxable estate. That mismatch is not a loophole in the sense of an accident nobody noticed. The IRS has known about it since the 1980s and has largely left it alone.

What Makes a Trust “Intentionally Defective”

A trust becomes “defective” when it is drafted so that it counts as a completed gift for estate and gift tax purposes but still names the grantor as the income tax owner. The defect is deliberate. It has nothing to do with sloppy drafting.

The practical effect runs in two directions at once. First, because the trust is irrevocable and the grantor has given up dominion over the assets, anything transferred in (and any appreciation on it) sits outside the grantor’s taxable estate going forward. Second, because the grantor still pays the trust’s income tax bill under Sections 671 through 679, the trust itself grows undiminished by tax drag. Every tax payment the grantor makes on the trust’s behalf is, by IRS ruling, not treated as an additional gift, even though it functions exactly like one economically.

Revenue Ruling 85-13 is the piece that makes IDGT sales work at all. In it, the IRS concluded that a sale between a grantor and a trust the grantor is treated as owning for income tax purposes is not a recognition event, because you cannot sell something to yourself. No gain, no loss, no installment note interest treated as taxable income to the seller. That 1985 ruling, combined with the swap power under Section 675, is the entire legal foundation beneath a multi-million-dollar IDGT sale transaction.

The 2026 Planning Window

Timing shapes this planning more than most clients expect. Before the One Big Beautiful Bill Act, the doubled exemption created under the 2017 tax law was scheduled to sunset at the end of 2025, cutting the exemption roughly in half. That cliff drove a wave of rushed gifting in 2024 and 2025 among families worried about losing the higher number. OBBBA removed the cliff and made the $15 million exemption permanent with ongoing inflation indexing, which takes some urgency out of the room but does not eliminate the case for planning.

Permanence changes the calculus without removing the reasons to act. Interest rates still move month to month. The Section 7520 rate has ranged between 4.6% and 5.2% across the first seven months of 2026 alone, and a GRAT funded in a lower-rate month locks in an easier hurdle for the rest of its term. Business valuations move too, sometimes down during a rough year, which is precisely when transferring an asset out of the estate costs the least in gift tax terms. And state estate taxes have not gone anywhere. A number of states tax estates well below $15 million, so families who assume the federal number is the only number sometimes get a state tax bill they never planned for.

The Three Structures Advisors Actually Use

Grantor trust status is a tax attribute, not a structure by itself. It gets layered onto a handful of actual trust designs, and three account for most of the planning done for high-net-worth families today.

Intentionally Defective Grantor Trusts (IDGTs)

An IDGT sale starts with a gift, usually 10% of the intended transaction value, to seed the trust. The grantor then sells an appreciating asset to the trust in exchange for a promissory note, typically bearing interest at the applicable federal rate rather than a commercial rate. Because Rev. Rul. 85-13 treats the sale as a nonevent for income tax purposes, no capital gain is triggered on the transfer, and the note’s interest payments are not taxable income to the grantor even though the trust deducts nothing either.

If the asset inside the trust grows faster than the note’s interest rate, the excess growth accrues to trust beneficiaries outside the grantor’s estate, gift tax and estate tax free. This is where the structure most often gets funded with discounted interests in a family limited partnership or LLC rather than direct ownership of an operating business or real estate. Fractional, non-controlling interests in a closely held entity typically qualify for lack-of-control and lack-of-marketability discounts, so a $10 million enterprise might transfer at an appraised value well below that figure. That same discounting practice is exactly what current IRS enforcement attention on valuation discount for estate planning targets, and it is worth reading up on before an IDGT sale gets funded with anything other than marketable securities.

The grantor keeps a swap power under Section 675(4)(C), letting them exchange low-basis trust assets for high-basis assets of equal value before death. That resets basis at death for the assets pulled back into the estate, since assets in the grantor’s own estate get a stepped-up basis under Section 1014 while assets left in the trust do not.

Grantor Retained Annuity Trusts (GRATs)

A GRAT works on a shorter clock. The grantor transfers an asset to the trust and retains the right to fixed annuity payments for a set term, often two to ten years. At the end of the term, whatever remains passes to the named beneficiaries. The taxable gift at funding is calculated using the Section 7520 rate, which for July 2026 sits at 5.2%, and can be pushed close to zero by sizing the annuity payments so the present value of the retained interest nearly equals the value transferred in. Practitioners call this a “zeroed-out” GRAT, a technique the Tax Court upheld in Walton v. Commissioner in 2000.

If the trust’s assets appreciate faster than the 7520 rate in effect at funding, the excess passes to beneficiaries gift tax free when the term ends. If they don’t, the grantor simply gets the assets back through the annuity payments and nothing is lost beyond legal fees, which is why GRATs are sometimes described as a low-downside bet on outperformance. They are not, however, free of risk: die during the term and some or all of the trust reverts to the taxable estate under Section 2036, which is why shorter terms and rolling GRAT series are common in practice.

Spousal Lifetime Access Trusts (SLATs)

A SLAT is an irrevocable trust one spouse creates for the benefit of the other spouse (and often descendants), designed as a grantor trust so the creating spouse pays the income tax. The beneficiary spouse can receive distributions for health, education, maintenance, and support, or broader standards depending on drafting, which gives the family practical access to funds that have technically left both spouses’ combined taxable estate.

Married couples sometimes set up SLATs for each other. Done carelessly, this triggers the reciprocal trust doctrine, where a court unwinds two trusts that are too similar in terms and treats each spouse as still owning the trust created for their own benefit. Avoiding that outcome means building in real differences between the two trusts: different trustees, different distribution standards, different funding amounts, and different timing. A SLAT also raises a harder question than the other two structures: what happens on divorce, when the beneficiary spouse is no longer a spouse but the trust’s terms may still name them. Drafting for that scenario up front avoids a fight nobody wants to have later.

Structure Comparison at a Glance

Laid side by side, the trade-offs stop looking like three flavors of the same idea and start looking like three different tools for three different situations.

A Worked Example: A $10 Million IDGT Installment Sale

Numbers make the mechanics concrete. Assume a business owner seeds a trust with a $1,000,000 gift, then sells a $10,000,000 non-controlling interest in a family operating company to the trust for a nine-year promissory note. Assume, for illustration only, an applicable federal rate on the note of 4.3% and asset growth inside the trust of 9% a year, roughly the kind of spread that makes this structure attractive to a business owner who believes in the company’s growth. These growth and rate assumptions are illustrative, not a forecast, and actual outcomes vary by asset, market, and note terms.

Each year the trust pays interest-only on the note; at the end of the term it repays principal. The trust’s assets, growing at 9% while owing interest at 4.3%, build a spread that accrues entirely to the beneficiaries because the sale itself triggered no capital gain and the grantor’s tax payments on trust income are not additional gifts.

The IDGT bar sits highest in this illustration because the full $10 million asset base, not just the retained-interest spread, is out of the estate from day one and compounding at the full 9% assumption while the offsetting note sits at a fixed 4.3%. The GRAT and SLAT figures assume smaller starting transfers and, in the GRAT’s case, only the excess above the annuity payments actually leaves the estate.

“I think GRATs get oversold to clients as a standalone fix. The math only works if the asset genuinely outgrows the 7520 rate, and a 5.2% hurdle in mid-2026 is not nothing. For a business owner with a growth story, an IDGT sale usually does more work per dollar of legal fee.”

Common Mistakes That Undo the Planning

Grantor trust structures fail for predictable reasons, and most of them are avoidable with more careful drafting or administration rather than a different strategy altogether. In practice, the same five issues surface again and again across audits and malpractice claims, regardless of which of the three structures a family chose.

• Undercapitalized seed gifts. A note that isn’t backed by enough equity in the trust starts to look like a disguised gift of the whole sale to the IRS, not a genuine debt.
• Ignoring the note’s terms after closing. Interest that goes unpaid, or a note that gets forgiven informally, undermines the argument that this was ever a real sale.
• Reciprocal SLATs that mirror each other too closely. Same trustee, same distribution language, same funding date. That pattern invites exactly the doctrine the structure was supposed to avoid.
• Funding with hard-to-value assets and a thin appraisal. Weak valuation support on discounted FLP or LLC interests is the single most common audit trigger in this area.
• Forgetting income tax cash flow. A grantor who has not budgeted for years of paying tax on trust income they never personally receive can end up strapped, sometimes forced to sell other assets at an inconvenient time.

A Practical Planning Checklist

Key Takeaways

Frequently Asked Questions

Is an IDGT sale legal, or is it a loophole the IRS is likely to close?
It is legal under current law. Rev. Rul. 85-13 and Sections 671 through 679 have supported this structure since the 1980s. Congress has floated legislation to curb the technique multiple times without passing it, so the possibility of a future change is real, but nothing currently on the books limits it.

Do I need to file a gift tax return for an IDGT sale?
The seed gift into the trust requires a gift tax return. Whether the sale itself needs disclosure depends on the facts and the desire to start the statute of limitations running on valuation, which is a decision to make with counsel rather than skip by default.

Can I be a trustee of my own IDGT, GRAT, or SLAT?
Sometimes, but it depends on the specific powers involved and can create estate tax inclusion risk under Sections 2036 or 2038 if not handled carefully. Many practitioners recommend an independent trustee, at least for discretionary distribution decisions.

What happens to a GRAT if the grantor dies during the term?
Under Section 2036, the value of the assets needed to produce the remaining annuity payments is generally pulled back into the grantor’s taxable estate. This is the core mortality risk of a GRAT and is why shorter terms and rolling GRATs are common.

Are SLATs only useful for very large estates?
They are most valuable above the federal exemption, but some families use them below that threshold for asset protection or state estate tax reasons, since a number of states impose their own estate tax at exemption levels far below the federal $15 million figure.

How is grantor trust status different from a trust being included in my taxable estate?
They are separate questions answered by different code sections. Grantor trust status under Sections 671 through 679 controls who pays income tax on the trust’s earnings during the grantor’s life. Estate tax inclusion under Sections 2036 through 2038 controls whether the trust’s assets get pulled back into the gross estate at death. A well-built IDGT, GRAT, or SLAT is a grantor trust for income tax purposes while, if drafted and administered correctly, staying outside the taxable estate for transfer tax purposes. Mixing up the two questions is a common source of confusion even among experienced advisors.

References

• Internal Revenue Code, Subpart E, Sections 671–679 (grantor trust rules).
• Rev. Rul. 85-13, 1985-1 C.B. 184 (sale between grantor and grantor trust not a recognition event).
• Walton v. Commissioner, 115 T.C. 589 (2000) (upholding zeroed-out GRAT valuation).
• Internal Revenue Code Section 7520; IRS monthly Section 7520 interest rate tables (July 2026 rate: 5.2%).
• Morgan Lewis, “IRS Announces Increased Gift and Estate Tax Exemption Amounts for 2026” (October 28, 2025) — secondary source, law firm client alert.
• Internal Revenue Code Sections 1014, 2036, 2038, 2701, and 2702 (basis step-up and valuation/inclusion rules referenced above).

None of this changes the basic bargain a grantor trust asks a family to make: give up control today in exchange for a tax result decades from now, and keep paying someone else’s tax bill in the meantime. That trade only makes sense for families who were already going to leave assets alone to grow. For everyone else, it’s an expensive way to solve a problem they don’t actually have. The families who benefit most tend to already know, before the first meeting with counsel, exactly which asset they’re willing to give up control over. The planning just gets them there with less tax friction than they expected.