12 Oct How an IDGT Builds a Tax-Free Dynasty

If you’ve been following this series, you know three things. The generation-skipping transfer tax is a 40% flat tax on wealth that passes to grandchildren or beyond. The IDGT is an irrevocable trust where the grantor pays the income tax while the assets grow outside the estate. And the way you allocate your GST exemption determines whether a trust’s distributions to skip persons are tax-free or not.

This article puts it all together. One of the most powerful multigenerational planning structures available today isn’t either tool in isolation. It’s the combination: a dynasty IDGT funded with discounted assets, sheltered by GST exemption, and built to last for generations.

The Setup

Here’s how it works.

The grantor creates an IDGT in a state that allows perpetual or long-duration trusts. Several states allow this, and the right choice depends on the trust’s terms and the family’s situation. The trust is irrevocable, the grantor retains a power that makes it a grantor trust for income tax, and the trust is drafted to benefit children, grandchildren, and all future descendants.

Step one: the seed gift. The grantor transfers assets to the trust as a gift, using lifetime gift and estate tax exemption. Critically, the grantor also allocates GST exemption to this gift to ensure the trust is fully exempt from the generation-skipping transfer tax.

Step two: the installment sale. The grantor sells additional assets to the trust in exchange for a promissory note at the AFR. Because the trust is a grantor trust, there’s no income tax on the sale. The assets are now in the trust, growing for the benefit of future generations.

Where the Multiplier Comes From

The multiplying effect in this structure comes from three places.

First, valuation discounts. When the transferred asset is an interest in a family LLC, a family limited partnership, or a closely held business, it may qualify for discounts for lack of marketability and lack of control. The discount means a family can move more economic value into the trust while using less exemption than the asset is actually worth. For families thinking about selling a business, this is often the first move.

Second, growth above the AFR. The installment note bears interest at the applicable federal rate, which is set monthly by the IRS and has historically been well below the rate of return on private business interests, real estate, and other appreciating assets. Every dollar of growth above the AFR passes to the trust beneficiaries free of transfer tax.

Third, the income tax subsidy. The grantor pays the income tax on trust earnings from personal assets. The trust never pays income tax. Over decades, this compounding advantage can be substantial. A trust that keeps 100% of its returns reinvested will be dramatically larger after 30 years than one that loses 25% to 35% annually in taxes.

The GST Exemption Makes It Permanent

Without GST exemption allocation, even a perfectly structured IDGT eventually runs into the generation-skipping transfer tax. When the grantor’s children die and the trust continues for grandchildren, that’s a taxable termination. When the trustee distributes to a grandchild, that’s a taxable distribution. Either way, the 40% tax applies.

With GST exemption allocation, those events are tax-free. No GST tax on distributions. No GST tax on terminations. The trust can continue for generations, compounding returns and making distributions to grandchildren and great-grandchildren, all without triggering any transfer tax.

That’s the dynasty part. All outside the transfer tax system. All distributable to future generations without estate, gift, or GST tax.

What Makes It Work (And What Breaks It)

Several things have to go right for this structure to deliver.

The grantor needs enough liquidity to pay the trust’s income tax from personal assets. If the grantor can’t afford the payments, the trust agreement should allow the trustee to reimburse the grantor. But the trust should use that provision sparingly. Routine reimbursement risks pulling the assets back into the grantor’s estate.

The GST exemption allocation has to be made on time, on the gift tax return for the year the transfer is made. Late allocations are possible but cost more. The allocation for a late filing is based on the trust’s value at the time of the late allocation, not the original gift date. If the trust has appreciated, you’re spending more exemption for less coverage.

The trust has to be properly administered in a state with favorable trust laws. That means a qualified trustee in the situs state, regular accountings, and compliance with the trust’s terms. A dynasty trust that isn’t properly maintained can lose its favorable treatment.

And the advisors have to coordinate. The estate attorney drafts the trust. The CPA handles the gift tax return and the GST exemption allocation. The financial advisor manages the trust investments and coordinates the overall plan. If any one of them misses a step, the exemption, the discount, the inclusion ratio, or the grantor trust status can be compromised.

The Bottom Line

For families with significant wealth and a long time horizon, the dynasty IDGT is one of the most powerful multigenerational planning structure currently available. It removes assets from the estate, eliminates income tax drag on trust growth, and when combined with proper GST exemption allocation, shields distributions to future generations from the 40% generation-skipping transfer tax.

But it requires getting every piece right: the drafting, the funding, the allocation, the administration, and the coordination among advisors. This isn’t a trust you set up and forget. It’s a plan you build with your team and manage for decades.

Ready to build a your plan?

For advisors: Have a client dealing with this? I do quick consult calls for advisors working through complex planning situations.

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For business owners and families: At Garza Law, we are selective in choosing our clientele. We work with a select group of families every year to help them protect their legacy. If what you read here raised questions about your own situation, you can apply here:  Apply Here

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How ILITs Help High-Net-Worth Families. Another irrevocable trust structure with its own GST planning needs.

Estate Planning for Business Owners. The complete picture for families with significant business interests.