What it means
Without this tax, a wealthy family could pass assets straight to grandchildren and skip the estate tax that would otherwise be charged when the middle generation died. The rules close that route by imposing a separate tax on what the law calls a skip person, meaning a recipient two or more generations below the person making the transfer.
The tax is charged at a flat rate equal to the highest estate tax rate, currently 40%, and it applies in addition to any gift or estate tax already due. That stacking is what makes it dangerous: an unplanned transfer can face two layers of tax on the same money.
Each person has a lifetime exemption amount, indexed for inflation, that can be allocated to transfers to shelter them from the tax. Allocating that exemption correctly and on time is the whole game in practice, because an exemption applied to a trust early, before the assets grow, shelters all of the later growth as well.
There are three taxable events to watch. A direct skip is an outright transfer to a skip person; a taxable distribution is a payment from a trust to a skip person; and a taxable termination happens when the last non-skip beneficiary's interest ends and only skip persons remain.
Two nuances matter for ordinary families. The predeceased parent exception moves a grandchild up a generation if their parent has already died, and transfers that qualify as direct payments of tuition or medical costs are generally outside the rules entirely.
In practice
Real-world examples
Example 1
A retired manufacturer settles $20,000,000 into a trust for grandchildren and allocates $14,000,000 of exemption, leaving an inclusion ratio of 0.30. Every later distribution to a grandchild carries a 40% tax on 30% of the amount paid out.
Example 2
A family instead funds a trust with $10,000,000 while allocating $10,000,000 of exemption, producing an inclusion ratio of zero. The trust later grows to $28,000,000 and distributes freely to grandchildren with no generation-skipping tax at all.
Example 3
A grandparent pays $60,000 of university tuition directly to the institution rather than giving the cash to a grandchild. The direct payment falls outside the transfer rules entirely and uses none of the exemption.
Think of it
Imagine a toll road where the government charges a fee every time a car passes a checkpoint. If you try to build a private shortcut that jumps past checkpoint two straight to checkpoint three, the toll operator charges an extra bypass fee to make up for the skipped stop.
Formula
Calculation
Generation-skipping transfer tax = taxable amount x 40% x inclusion ratio, where inclusion ratio = 1 - (exemption allocated / value of the transfer).
Take a simple direct skip first. A grandparent gives $20,000,000 outright to grandchildren and allocates $14,000,000 of remaining exemption to the gift. The exposed amount is $20,000,000 - $14,000,000 = $6,000,000, and the tax is $6,000,000 x 40% = $2,400,000.
Now take the same $20,000,000 placed into a long-term trust with $14,000,000 of exemption allocated. The applicable fraction is $14,000,000 / $20,000,000 = 0.70, so the inclusion ratio is 1 - 0.70 = 0.30, and 30% of everything the trust ever distributes to grandchildren is exposed.
If that trust later distributes $5,000,000 to grandchildren, the taxable amount is $5,000,000 x 0.30 = $1,500,000, and the tax due is $1,500,000 x 40% = $600,000. Had the full $20,000,000 been sheltered at the outset, the inclusion ratio would be zero and no tax would arise on any later distribution, however much the trust had grown.Case study
Seen in the real world
The Vance family and their fictional business, Vance Fabrication, appear here purely as an illustrative example. The founder wanted to leave a $20,000,000 share portfolio to his five grandchildren, having already provided for his two children through the operating company.
His first draft left the portfolio outright to the grandchildren on his death. His adviser modelled the outcome: with $14,000,000 of exemption available, $6,000,000 would be exposed, generating $6,000,000 x 40% = $2,400,000 of generation-skipping tax on top of the estate tax already payable on the same assets.
In the illustrative alternative, the founder settled a smaller amount, $14,000,000, into a trust straight away and allocated the full $14,000,000 of exemption to it, giving an inclusion ratio of zero. The remaining $6,000,000 went to his children in the ordinary way. When the trust later grew, all of that growth passed to the grandchildren free of the skipping tax, and the family's planning cost was a few thousand dollars of professional fees rather than a seven-figure tax bill.
Watch out
Common mistakes
- Assuming that leaving assets to grandchildren saves tax, when the generation-skipping rules are designed specifically to remove that advantage.
- Forgetting to allocate exemption to a trust at the time of funding, which locks in an inclusion ratio above zero and taxes all future growth.
- Confusing this tax with estate tax and budgeting for only one; the two can apply to the same transfer.
Questions
People also ask
Who counts as a skip person?
Generally a relative two or more generations below the giver, such as a grandchild, or an unrelated individual more than 37.5 years younger.
What rate applies?
A flat 40%, equal to the top federal estate tax rate, applied to the taxable amount after the inclusion ratio is taken into account.
Does the tax apply outside the United States?
No, this is a US federal tax, though several other countries use different mechanisms such as inheritance tax charges on trusts to achieve a similar result.