Intentionally Defective Grantor Trust (IDGT): The Stealth Strategy Millionaires Use

An intentionally defective grantor trust (IDGT) is an irrevocable trust that removes assets from your taxable estate while leaving you, the grantor, responsible for the income tax on everything the trust earns. That mismatch is the entire point. Every tax dollar you pay on the trust’s behalf is a tax-free gift to your heirs, and every dollar of growth inside the trust happens outside your estate. I am a licensed insurance professional, not an attorney, and your attorney drafts the trust. My role is the life insurance that usually sits inside or alongside it, so this article explains the structure and then shows exactly where the policy fits.

For the bigger picture of how trusts and insurance work together, see my estate planning page.

What is an intentionally defective grantor trust?

An IDGT is a trust that is “defective” for income tax purposes but effective for estate tax purposes, which means the IRS ignores it when computing your income tax and respects it when computing your estate. The trust gets that split personality on purpose. Your attorney includes a power in the trust document that triggers the grantor trust rules in §671 through §679 without causing estate inclusion under §2036 or §2038.

The most common trigger is the power to substitute assets of equivalent value under §675(4)(C). Others include the power to borrow from the trust without adequate security and the power of a non-adverse trustee to add charitable beneficiaries. Each one makes you the income tax owner while keeping the assets out of your estate.

Once the trust exists, you transfer assets into it by gift, by sale, or by a combination. Typical assets are:

• Closely held business interests, often S corporation or LLC units.
• Real estate expected to appreciate.
• Marketable securities you do not plan to sell.
• Cash used to pay life insurance premiums.

Why does the grantor paying the income tax help?

The grantor’s payment of the trust’s income tax is not a gift to the trust, according to Rev. Rul. 2004-64, which means you can shrink your taxable estate every year without using any gift tax exemption. The trust’s assets compound at a pre-tax rate while your estate shrinks by the tax you pay.

Consider a trust holding $5 million that earns 7 percent, or $350,000 a year. If you pay roughly $130,000 of income tax on that from your own funds, your estate is $130,000 smaller and the trust is $350,000 larger, every year, with no gift reported. Over fifteen years the difference runs into the millions.

The same ruling carries a warning. If the trust document requires the trustee to reimburse you for the tax, the reimbursement right can pull the assets back into your estate. If reimbursement is purely discretionary with an independent trustee and state law does not expose the trust to your creditors, it generally does not. Your attorney will choose the language carefully.

How does an installment sale to an IDGT work?

An installment sale to an IDGT lets you move a large asset into the trust in exchange for a promissory note, so the future growth of the asset lands in the trust while only the note, a fixed number, stays in your estate. Because you and the trust are the same taxpayer for income tax purposes, the sale itself is not a taxable event under Rev. Rul. 85-13; there is no capital gain and no interest income to report.

The usual sequence:

1. You gift seed capital to the trust, commonly about 10 percent of the value you intend to sell, so the trust has real equity behind the note.
2. The trust buys the asset from you at appraised fair market value, often with a valuation discount for lack of control or marketability.
3. The trust pays with an interest-only or amortizing note at the applicable federal rate published monthly by the IRS at irs.gov.
4. Cash flow from the asset services the note. Growth above the AFR accrues to the trust beneficiaries free of estate and gift tax.

The risks are real and your attorney and CPA should walk through them: a valuation the IRS disputes, an asset that fails to out-earn the note, and the unsettled question of what happens if you die while the note is outstanding. That last risk is the first place life insurance enters the design.

How is life insurance paired with an IDGT?

Life insurance is paired with an IDGT in one of two ways: a separate irrevocable life insurance trust (ILIT) that owns the policy, or the IDGT itself owning the policy and paying premiums from the cash flow of the assets it holds. Each has a place, and I have built both with clients’ attorneys.

ILIT alongside the IDGT

An ILIT is a purpose-built grantor trust whose only job is to own a policy and keep the death benefit out of your estate under §2042. You fund premiums with annual exclusion gifts and Crummey notices. It works, but every premium consumes exemption or annual exclusion, and the ILIT has no income of its own.

IDGT-owned policy

When the IDGT already holds an income-producing asset, the trustee can use that cash flow to pay premiums directly. No new gifts, no Crummey letters, no exemption used. Because the trust is a grantor trust, the policy can be purchased on your life without triggering the transfer-for-value rule, and the death benefit is still outside your estate as long as you hold no incidents of ownership.

The death benefit then does three jobs:

• Pays off the installment note if you die early, so the trust keeps the asset intact.
• Creates liquidity for estate tax on assets that remain in your estate.
• Equalizes inheritances when one child receives the business and another does not.

On the insurance side I match the policy to the job. A guaranteed universal life or whole life contract is right for permanent estate liquidity. A cash-value design can add a second layer of trust assets that grow tax-deferred under §7702. I shop the case across my network of roughly 50 carriers so the trust is not overpaying for the coverage.

What an IDGT cannot do

An IDGT cannot give you control or personal benefit from the assets without risking estate inclusion, and it cannot be unwound easily once funded. It also rests on rules Congress has proposed changing more than once. For 2026 the federal estate and gift exemption is $15 million per person under the 2025 tax legislation, indexed for inflation after that, and the IRS keeps the current figure on its estate tax page. Families well above that number are the ones who use IDGTs. Confirm the exemption and the trust design with your attorney and CPA before acting.

Frequently Asked Questions

Why is it called “defective”?

Because the trust deliberately fails the income tax rules that would make it a separate taxpayer. The grantor trust provisions treat you as the owner for income tax, so you pay the tax and transactions between you and the trust are ignored. The trust still succeeds at its estate tax purpose, which is why the defect is intentional.

Does the grantor have to pay the trust’s income tax forever?

No. Most IDGTs give an independent trustee or the grantor the ability to turn off grantor trust status, for example by releasing the substitution power. After that the trust pays its own tax. Clients often keep grantor status while they are working and turn it off when the tax burden stops making sense.

Can an IDGT own S corporation stock?

Yes. A grantor trust is a permitted S corporation shareholder under §1361(c)(2)(A)(i) while the grantor is alive and for two years after death. If grantor status ends, the trust must qualify as a QSST or ESBT to keep the S election. Your attorney and CPA coordinate this before any transfer.

What is the difference between an IDGT and an ILIT?

Both are irrevocable grantor trusts outside your estate. An ILIT is designed narrowly to own life insurance funded by gifts. An IDGT is designed to hold appreciating assets, often bought with a note, and can own life insurance paid from its own cash flow. Many plans use an IDGT and skip the separate ILIT.

How much life insurance does an IDGT plan need?

Enough to retire the installment note and cover projected estate tax on the assets still in your name, adjusted for the growth you expect between now and life expectancy. I run that calculation with your attorney’s projections and then illustrate the coverage across carriers so the trust buys the right amount at the right price.

If your attorney is designing an IDGT, or you suspect your estate is large enough to need one, I will coordinate the insurance side and illustrate the policy options over Zoom. Start on our services page.