Glossary term
Intentionally Defective Grantor Trust (IDGT)
An intentionally defective grantor trust is an irrevocable trust designed to be outside the grantor’s estate while still treated as owned by the grantor for income tax purposes.
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What Is an Intentionally Defective Grantor Trust?
An intentionally defective grantor trust, or IDGT, is an irrevocable trust designed so the trust assets may be outside the grantor’s estate for estate-tax purposes while the grantor is still treated as the owner for income-tax purposes. The “defect” is intentional: it refers to income-tax treatment, not a mistake in drafting.
IDGTs are advanced estate-planning tools used mainly in high-net-worth planning. They require careful legal and tax advice because the benefits depend on trust design, valuation, cash flow, gift-tax rules, and future tax law.
Key Takeaways
- An IDGT is intentionally structured as a grantor trust for income-tax purposes.
- The grantor typically pays income tax on trust income, which can let trust assets grow without being reduced by that tax.
- The trust may be designed to move appreciation outside the taxable estate.
- IDGTs are complex and should not be used without qualified estate and tax counsel.
How the Tax Split Works
The core planning idea is a split between income-tax ownership and estate-tax treatment. The grantor may be treated as owning the trust for income tax, so trust income is reported by the grantor. At the same time, the trust may be structured so transferred assets and future appreciation are not included in the grantor’s taxable estate.
Tax Lens | Typical IDGT Treatment |
|---|---|
Income tax | Grantor is treated as owner of the trust income. |
Estate tax | Trust may be designed to keep assets outside the taxable estate. |
Gift tax | Transfers can use exemption or require gift-tax analysis. |
Basis | Basis treatment depends on inclusion, transfer structure, and tax rules. |
Why Planners Use It
An IDGT can let the trust grow for beneficiaries while the grantor pays the income tax from outside the trust. That tax payment can effectively preserve more trust assets without being treated the same way as an additional gift in many planning discussions. Some plans also involve a sale of appreciating assets to the trust in exchange for a promissory note.
The strategy is sensitive to interest rates, asset performance, valuation discounts, cash-flow assumptions, and tax-law risk. If the assets do not appreciate enough, or if the note and tax obligations strain liquidity, the planning result can disappoint.
Basis and Estate Inclusion
Recent IRS guidance has reinforced that assets in an irrevocable grantor trust that are not included in the grantor’s gross estate generally do not receive a basis adjustment at the grantor’s death. That makes basis planning a major part of IDGT analysis, not an afterthought.
The Bottom Line
An IDGT is a sophisticated trust strategy built around different income-tax and estate-tax treatment. It can be powerful in the right circumstances, but it is technical, high-stakes, and highly dependent on professional drafting and tax analysis.