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IDGTs: the trust that is 'defective' on purpose

Why deliberately keeping a trust taxable to you — an intentionally defective grantor trust — is one of the most powerful, if confusingly named, wealth-transfer tools.

The name is terrible. An intentionally defective grantor trust (IDGT) is not broken — it is deliberately designed so that YOU, the grantor, remain responsible for its income taxes, even though the assets are legally out of your estate. That mismatch (out of your estate for estate tax, but taxed to you for income tax) is not a flaw; it is the entire point, and it quietly transfers extra wealth to your heirs year after year.

Two tax systems, two answers

An IDGT is drafted to be 'defective' for income-tax purposes — meaning the grantor pays the tax on the trust's income — while being 'complete' for estate and gift-tax purposes, so the assets sit outside the taxable estate. The trust achieves this through specific retained powers that trigger the grantor-trust income-tax rules without pulling the assets back into the estate.

Paying the trust's taxes is a tax-free gift

Because the grantor pays the income tax on trust earnings out of personal funds, the trust's assets grow UNBURDENED by taxes — and the tax the grantor pays is effectively an additional gift to the beneficiaries that uses none of the exemption and incurs no gift tax. Over decades this 'tax burn' can transfer millions extra to heirs.

The classic move: sell assets to the IDGT

1
Seed the trust
Make a gift to the IDGT (often around 10% of the intended sale) so it has equity and the sale is respected.
2
Sell appreciating assets to the trust
Sell assets to the IDGT in exchange for a promissory note at the IRS minimum interest rate (the AFR).
3
No capital gains on the sale
Because the trust is a grantor trust, selling to it is like selling to yourself — no capital gains tax is triggered on the sale.
4
Freeze and shift
The note is a fixed value in your estate; all growth above the low AFR passes to heirs inside the trust, outside your estate.

IDGT sale vs. GRAT

Feature	Sale to IDGT	GRAT
Hurdle rate	Low AFR	Higher 7520 rate
If grantor dies mid-term	Note still owed; less punitive	Assets pulled back into estate
GST (dynasty) friendly	Yes — can allocate GST exemption	Awkward for skips
Upfront gift required	Small seed gift	Little to none

Two estate-freeze techniques compared

The tax burn is a feature until it is a burden

Paying someone else's trust's taxes indefinitely can strain your own cash flow. Well-drafted IDGTs include a 'toggle' — a way to turn off grantor status — so you can stop the tax burn if it becomes too heavy. Designing and administering all of this is squarely attorney-and-CPA work, and none of this is individualized advice.

The bottom line

An IDGT is 'defective' on purpose: the grantor keeps paying income tax on assets that are already outside the estate, so those assets compound tax-free AND the tax payments themselves become exemption-free gifts to heirs. Paired with an installment sale at the low AFR, it freezes value and shifts growth even more effectively than a GRAT for many goals, especially dynasty planning. The main watch-outs are cash-flow strain and precise drafting — specialist territory throughout.

Check your understanding

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What is 'defective' about an intentionally defective grantor trust?

Not quite — try again.

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