05 Oct Your GST Exemption Won’t Allocate Itself

Every person gets a GST exemption. As of 2026, it’s $15 million. That number is the total amount you can shield from the generation-skipping transfer tax across every trust you fund, every gift you make to a grandchild, and every structure you build for future generations. Once it’s used up, it’s gone.

Unlike the estate tax exemption, the GST exemption isn’t portable between spouses. If one spouse dies without using theirs, the survivor can’t pick it up. It belongs to the person, not the couple. That makes it one of the most valuable and least forgiving planning tools in the toolkit.

And one of the biggest mistakes people make with it is treating it like it takes care of itself.

The Automatic Allocation Trap

The tax code includes a set of automatic allocation rules designed to apply GST exemption to certain transfers without the taxpayer doing anything. That probably sounds helpful. In practice, these defaults create two problems that show up repeatedly in the plans I review.

First, the automatic rules sometimes allocate exemption where you don’t need it. A trust that only benefits your children isn’t making distributions to skip persons. Exemption applied there is exemption wasted. It’s gone from your lifetime total, and it did nothing.

Second, the rules miss transfers that do need coverage. An irrevocable life insurance trust with grandchildren as beneficiaries, for example, may not receive automatic allocation depending on how it’s structured. The trust sits uncovered. Nobody notices until a distribution to a grandchild triggers a 40% tax that could have been avoided entirely.

The gap between what the automatic rules cover and what your plan actually needs is where the exposure lives. 

Allocation Is a Planning Decision

The fix isn’t complicated, but it does require attention. Every transfer to a trust should trigger a deliberate decision: does this trust need GST exemption, how much, and when should it be allocated?

That decision gets documented on Form 709, the gift tax return. Filing on time matters. If you make a gift to a trust in 2026 and don’t file the 709 until 2029, you’ve lost three years. During those three years, the trust’s value may have grown. A trust that could have been fully covered with $2 million of exemption in 2026 might need $3.5 million by the time you get around to it. The exemption required to fully protect a trust is measured against the trust’s value at the time of allocation, not at the time of the original transfer.

That timing problem compounds. Every year you wait is a year the trust grows, and a year your finite exemption has to stretch further to do the same job.

Three Ways Allocation Goes Wrong

The families I work with don’t usually have an exemption problem. They have a tracking problem. Here are the three patterns I see most often.

Partial coverage. The grantor transfers $10 million to an irrevocable trust but only has $5 million of remaining exemption. Half the trust is protected. Half isn’t. Every future distribution to a grandchild from that trust will be partially taxable, and the math on that partial exposure follows the trust for its entire life.

Missed or late allocation. A gift was made to a trust years ago, the 709 wasn’t filed on time, and the automatic allocation rules didn’t apply. The trust has been growing uncovered. By the time someone catches it, the value has doubled or tripled, and the exemption needed to fix it has grown with it.

Uncoordinated additions. The grantor makes additional gifts to a trust that was already fully exempt. Without allocating additional exemption to match the new contributions, the trust’s protection is diluted. What was once fully covered is now only partially covered, and nobody updated the tracking.

The Fix for a Trust with Mixed Exposure

If a trust is partially covered, there’s a tool to clean it up. A qualified severance splits one trust into two: one that’s fully exempt from GST tax and one that’s fully exposed. Same beneficiaries, same terms. The only difference is the GST treatment.

Once the split is done, you manage them differently. The exempt trust makes distributions to grandchildren and future generations freely. The non-exempt trust distributes to children, who aren’t skip persons and don’t trigger the tax. The children can then use their own GST exemption to fund new trusts for the next generation. Each generation takes advantage of its own exemption.

It’s a clean solution, but it’s reactive. The better approach is getting the allocation right from the start.

What Intentional Allocation Looks Like

In a well-designed plan, GST exemption allocation is part of the structure from the beginning, not an afterthought. That means three things.

First, every trust in the plan is designated as GST exempt or non-exempt from the beginning. The decision drives how the trust is structured, who the beneficiaries are, and how distributions are designed. Advisors who work with us know this as getting the inclusion ratio right. A trust with an inclusion ratio of zero is fully exempt. That’s the target for any trust designed to benefit grandchildren or span multiple generations.

Second, every transfer to a trust is matched with a timely 709 filing that documents the allocation explicitly. No reliance on automatic rules. No assumption that the defaults got it right.

Third, the plan is reviewed when values change. A business that was worth $5 million when the trust was funded might be worth $15 million five years later. If the estate plan hasn’t been updated to account for that growth, the exemption allocation that worked at funding may not work anymore.

The Next Step

GST exemption allocation is the foundation. The real power comes from combining it with the right trust structure. In the next article, I’ll show how intentionally defective grantor trusts and GST exemption work together to build the most powerful multigenerational planning structure available: the dynasty IDGT.

Is your GST allocation intentional?

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

Schedule a call: https://lgarzalaw.com/schedule-online/

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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