Imagine you build a $30 million business, pay estate tax when it passes to your children, and then watch your children pay estate tax again when the same wealth moves on to your grandchildren. Two layers of 40 percent federal tax can erode more than 60 percent of the original estate before a single grandchild sees a dollar. Congress noticed wealthy families using trusts to "skip" a generation and avoid that second hit, so in 1976 it built a backstop: the generation-skipping transfer tax. Today the GST tax is the third pillar of the federal transfer tax system, sitting alongside the estate and gift tax — and in 2026 the rules just changed in a meaningful way.
If you are a grandparent thinking about leaving money directly to grandchildren, a trustee administering a multi-generation trust, or a CPA advising high-net-worth clients, the GST tax is one of the trickiest corners of the Internal Revenue Code. Get it right and you can move $15 million per spouse to grandchildren — or great-grandchildren — entirely tax-free. Get it wrong and a single misallocated exemption can trigger a 40 percent flat tax decades later.
This guide walks through the mechanics: who counts as a skip person, what triggers the tax, how the $15 million exemption works under the One Big Beautiful Bill Act, and the planning structures that high-net-worth families use to compound wealth across multiple generations without burning through exemption.
Why the GST Tax Exists
Before 1976, a wealthy family could fund a trust during the grandparent's lifetime, give the children a lifetime income interest, and pass the principal to grandchildren when the children died. The trust assets were never owned outright by the middle generation, so no estate tax was due on the transfer from children to grandchildren. The wealth effectively skipped a generation of estate tax.
Congress saw this as a loophole that gave the ultra-wealthy a structural advantage over families who simply passed wealth in a straight line. The GST tax was designed to neutralize that advantage by imposing a separate, flat 40 percent tax on transfers that skip a generation. The idea is simple: every generation should bear a transfer tax exactly once, whether the wealth moves through a child or around the child.
In practice, the GST tax does not eliminate generation-skipping plans. It just imposes a cost — unless you use your GST exemption, which is the dollar amount each transferor can shield from the tax over a lifetime. With proper planning, families can still move enormous amounts to grandchildren and beyond, tax-free, by allocating the exemption strategically.
Who Counts as a "Skip Person"
The GST tax only applies to transfers to "skip persons." There are two ways to qualify.
Generational test. A relative is a skip person if they are two or more generations below the transferor. Grandchildren, great-grandchildren, and grandnieces or grandnephews all qualify. Children of a sibling are one generation below you, not two, so they are not skip persons.
Age test for non-relatives. For unrelated individuals — friends, employees, romantic partners — the recipient is a skip person if they are at least 37½ years younger than the transferor. This age threshold prevents wealthy families from routing assets through unrelated younger people to dodge the tax. Spouses are never skip persons regardless of age.
A trust can also be a skip person. If every present beneficiary of the trust is a skip person (for example, a trust paying income only to grandchildren), the trust itself is treated as a skip person and transfers into it can trigger immediate GST tax.
The Predeceased Parent Exception
The rules contain an important fairness provision. If your child dies before you do, your grandchildren "move up" a generation for GST purposes. A bequest from grandparent directly to a grandchild whose parent has already passed is not a skip — it is treated as a transfer to the equivalent of a child, since there is no longer a middle generation to tax. This exception, sometimes called the predeceased parent or predeceased child rule, applies to transfers to descendants of a predeceased child as well as to certain collateral relatives.
The Three Taxable Events
The GST tax is not a wealth tax. It only fires on specific events, which fall into three categories.
Direct Skip
A direct skip is an outright transfer — by gift or bequest — to a skip person. Writing a $100,000 check to your grandchild is a direct skip. Naming your grandchildren as beneficiaries of your IRA is a direct skip. Funding a trust whose only beneficiaries are grandchildren is also a direct skip, because the trust itself is a skip person.
For lifetime direct skips, the donor pays the tax. For transfers at death, the executor pays from the estate. The taxable amount is the value of the property transferred, and the tax is reported on Form 709 (during life) or Form 706 (at death), with Schedule R or R-1 handling the GST portion.
Taxable Distribution
A taxable distribution occurs when a trust pays out income or principal to a skip-person beneficiary, when not all current beneficiaries are skip persons. For example, a trust that benefits both children and grandchildren is a "mixed" trust — distributions to children are not subject to GST tax, but distributions to grandchildren are.
The beneficiary who receives the distribution pays the tax, reported on Form 706-GS(D). The trustee reports the distribution to the IRS and to the beneficiary on Form 706-GS(D-1).
Taxable Termination
A taxable termination happens when an interest in a trust ends — typically because a non-skip beneficiary dies — and the only remaining beneficiaries are skip persons. Example: a trust pays income to your child for life, then distributes principal to your grandchildren. When the child dies, the child's interest terminates, and the trust becomes a "pure" skip trust. That termination is a taxable event.
The trustee pays the tax from trust assets, using Form 706-GS(T). This is one of the most common GST events for old family trusts that were set up without anyone allocating exemption.
The Flat 40 Percent Rate (And Why It Stings)
Unlike the estate and gift tax, which uses a graduated rate that tops out at 40 percent only on the largest estates, the GST tax is a flat 40 percent. There is no lower bracket. The first dollar of taxable GST is taxed at the maximum federal estate tax rate.
This matters because the GST tax is layered on top of any gift or estate tax. A direct-skip lifetime gift can be hit with both gift tax and GST tax. The combined effective rate, when you gross up for the fact that the donor is also paying tax on the gift, can approach 64 percent of the underlying transfer. That is why exemption planning is essential before any large generation-skipping move.
The $15 Million Exemption Under OBBBA
Every transferor has a lifetime GST exemption that shields a set dollar amount from the tax. For decades the exemption tracked the estate and gift tax exemption, and it still does — they have been unified at the same dollar level since 2010.
For 2026, the One Big Beautiful Bill Act sets the GST exemption at $15 million per person, or $30 million for a married couple. That is up from $13.99 million in 2025, and unlike the Tax Cuts and Jobs Act of 2017, the OBBBA contains no sunset provision. The exemption is "permanent" in the sense that it does not automatically drop on a future date, though future Congresses can always revisit it. Beginning in 2027, the exemption is indexed annually for inflation using 2025 as the base year.
The annual gift tax exclusion — separately — is $19,000 per recipient in 2026. Annual exclusion gifts to skip persons are also exempt from GST tax, so a grandparent can give each grandchild $19,000 every year without touching either the gift or GST exemption.
Why "Permanent" Still Requires Vigilance
"Permanent" in tax law means "until Congress changes it." Estate-tax exemption levels have moved sharply in both directions over the last 25 years. The 2026 OBBBA-driven jump from $13.99 million to $15 million is modest, but the underlying point is that the exemption sits in a politically contested place. Families with potential taxable estates should not treat $15 million as a permanent ceiling — they should treat it as the current planning environment and revisit annually.
Allocating the GST Exemption
The exemption does not apply automatically to everything. You — or your executor — must allocate it to specific transfers, and once allocated, that exemption is gone. The allocation rules are notoriously technical, but three concepts cover most situations.
Automatic Allocation to Direct Skips
For outright lifetime gifts to skip persons, exemption is allocated automatically up to the value of the gift, unless the donor opts out on a timely-filed gift tax return. This usually works well: the gift is sheltered, and no GST tax is due.
Automatic Allocation to "GST Trusts"
Under Internal Revenue Code section 2632(c), exemption is also automatically allocated to "indirect skips" — gifts to trusts that meet the statutory definition of a GST trust. The default rule sweeps in many irrevocable trusts that are likely to make distributions to grandchildren or more remote descendants. Automatic allocation is a safety net, but it can be wasteful: exemption may attach to a trust that turns out never to make a skip distribution, leaving less exemption for more important transfers.
For this reason, sophisticated donors usually opt in or out explicitly on Form 709 each year rather than rely on the default.
Elective Allocation at Death
At death, the executor allocates any unused exemption on Schedule R of Form 706. Smart executors prioritize trusts most likely to benefit grandchildren and great-grandchildren, leaving non-skip transfers unsheltered (since they will not pay GST tax anyway).
The Inclusion Ratio
Once exemption is allocated to a trust, the trust receives an "inclusion ratio." A ratio of 0 means the trust is fully GST-exempt and no future distribution or termination will trigger tax. A ratio of 1 means the trust is fully exposed. A partial ratio means a proportional slice of every future distribution is subject to the 40 percent tax.
The goal is almost always an inclusion ratio of exactly 0 or exactly 1 for each trust. Trusts with fractional ratios become a long-running compliance headache. Professional drafters routinely split a single planned gift into two trusts — one fully exempt, one fully non-exempt — to keep the math clean and the planning options open.
Dynasty Trusts: Compounding Wealth Across Generations
The GST exemption becomes truly powerful when paired with a long-term trust. A "dynasty trust" is an irrevocable trust designed to hold assets for multiple generations — sometimes hundreds of years, depending on the state's rule against perpetuities.
The structure works like this: the grantor funds a dynasty trust with $15 million and allocates the full GST exemption on a timely Form 709. The trust now has an inclusion ratio of 0. Over the next 30 to 100 years, as the assets grow at, say, 7 percent annually, the trust can distribute income and principal to children, grandchildren, great-grandchildren, and beyond — and none of those distributions or terminations will trigger GST tax. The original $15 million can compound into hundreds of millions of dollars, all outside the federal transfer tax system.
States like South Dakota, Delaware, Nevada, and Alaska have abolished the rule against perpetuities entirely, allowing trusts to last in perpetuity. Combine a properly drafted, GST-exempt dynasty trust with a no-rule-against-perpetuities jurisdiction and a sound investment policy, and the wealth compounding effect is dramatic.
Common GST Tax Mistakes
The GST tax punishes inattention more than any other transfer tax. The most expensive mistakes are usually quiet ones.
Forgetting to allocate exemption on time. A timely Form 709 allocation locks in the value of the assets when transferred. A late allocation uses the value on the allocation date, which is often much higher. Donors who skip the gift tax return because the gift was under the annual exclusion limit can lose this benefit forever.
Funding old trusts with new contributions. Adding assets to a trust that was created before 1985 (and grandfathered out of GST) or to a trust with a partial inclusion ratio can pollute the ratio and convert an exempt vehicle into a mixed one. Always create a new trust for new exemption-shielded transfers.
Failing to opt out of automatic allocation. Default GST allocation can attach to trusts you did not intend to shelter — for example, an irrevocable life insurance trust where premiums are paid in small amounts year after year. The exemption gets used up on a trust that may never make a skip distribution.
Generation-skipping inheritances without a plan. Naming "my descendants" or "my grandchildren" as IRA beneficiaries without thinking through GST can trigger immediate tax at death. Coordinate beneficiary designations with the rest of the estate plan.
Ignoring state-level estate taxes. A handful of states impose their own estate tax with much lower exemption thresholds. Multi-generation planning has to coordinate federal GST with state-specific transfer taxes, especially in Massachusetts, Oregon, Washington, and New York.
Coordinating GST With Other Wealth Transfer Tools
The GST tax does not exist in isolation. The most effective high-net-worth plans use it in combination with other vehicles.
- Spousal lifetime access trusts (SLATs) can be drafted as GST-exempt dynasty trusts, sheltering up to $15 million per spouse from both estate and GST tax while preserving indirect access through the spouse.
- Grantor retained annuity trusts (GRATs) are difficult to coordinate with GST because the estate tax inclusion period prevents exemption allocation while the annuity is outstanding. GRAT planners generally treat GRATs as non-exempt and reserve exemption for other trusts.
- Charitable lead trusts (CLTs) can pay a charity for a term of years and then distribute the remainder to grandchildren. The GST issues are subtle but workable with careful drafting.
- 529 plans funded for grandchildren are technically gifts but receive a friendly five-year-averaging election that lets a grandparent contribute up to five years of annual exclusion at once — $95,000 per beneficiary in 2026, or $190,000 from a married couple — without using GST exemption.
Bookkeeping and Recordkeeping for Multi-Generation Plans
Long-term trusts only pay off if the paperwork holds up. Trustees who administer dynasty trusts for decades need to track the trust's inclusion ratio, every contribution to the trust, the basis of each asset, and a clean record of every Form 709 the grantor filed during life. When the trust eventually makes a taxable termination decades later, the IRS will want to see exactly how the inclusion ratio was computed at inception.
Plain-text accounting is well suited to this kind of multi-generation recordkeeping. Trustees can maintain a permanent, human-readable ledger of every contribution, distribution, valuation, and exemption allocation, with each entry timestamped and version-controlled. Spreadsheets get lost. Proprietary trust accounting software changes vendors. A plain-text ledger checked into a Git repository survives every software upgrade and stays auditable a century later.
Keep Your Multi-Generation Plan Auditable
If you are administering a dynasty trust, preserving clean records is just as important as drafting the trust correctly in the first place. Beancount.io provides plain-text accounting that is transparent, version-controlled, and AI-ready — exactly the qualities you want for assets that may need to be reconstructed decades from now. Get started for free and keep your financial records in a format that outlives every software platform.