Estate / generation-skipping

Dynasty trust and the state GST interaction

A dynasty trust is a bet that compounding without transfer tax beats the tax you pay to keep the money in the family. Allocate the GST exemption and the trust is exempt forever; skip it and every distribution carries 40%. Where a state can reach the trust at each generation, the advantage narrows again.

GST at funding$0.00State paid$32,311,057Federal paid$134,629,405

Wealth after the dynasty trust

$790,569,208

3 generations × 25 years

Outright, generation by generation

$101,211,883

Federal and state tax at every transfer

Advantage

$689,357,325

681% more in the trust

Inclusion ratio

0.000

Fully GST-exempt

Generation by generation

The dynasty trust compounds untouched; the outright path is taxed at every handover.

$689,357,325

Generation by generation
Generation	Dynasty trust	Outright	GST paid	State paid
1	$42,918,707	$21,631,028	$0.00	$0.00
2	$184,201,543	$46,790,139	$0.00	$0.00
3	$790,569,208	$101,211,883	$0.00	$0.00

The trust is outside every estate. The state line only bites where the state can reach a trust at each generation.

Wealth by generation

A GST-exempt trust pays no transfer tax between generations; outright gifts pay it every time.

Tax paid along the way

Federal estate tax on the outright path, GST on distributions, and state tax where it applies.

Canonical equations

The exact relationships implemented by this engine.

1 − allocated exemption / value · Zero means the trust is fully GST-exempt.

40% × value × inclusion ratio · Paid once, on the non-exempt share.

V · ((1 + g)(1 − d))ⁿ · No transfer tax between generations.

V · ((1 + g)(1 − d))ⁿ · (1 − t)ᵍ · Transfer tax at every generation.

Show model notation and computationOpen the symbolic form, the variable definitions, and the step-by-step derivation when you need the detail.

A clear path from inputs to results.

A dynasty trust is a bet that compounding without transfer tax beats the tax you pay to keep money in the family. Allocate the GST exemption and the trust is exempt forever; leave it unallocated and every distribution carries 40%. Where a state can reach the trust at each generation, the advantage narrows again — and several states do reach it.

Step-by-step methodWorked exampleAssumptions explained

How to use

Enter the amount funding the trust.

Set how much GST exemption you allocate at funding.

Choose the years per generation and how many generations to model.

Set the trust return and any annual distribution to beneficiaries.

Set the state rate and whether the state can reach the trust at each generation.

The formula

\text{inclusion} = 1 - \frac{X_{allocated}}{V} \;;\; \text{GST} = 0.40 \times V \times \text{inclusion}

Reference: IRC §2601–2664 (generation-skipping transfer tax), §2632 (allocation of exemption); state estate and trust taxation.

Worked example

$10m trust, three generations of 25 years

Inputs

Funding $10,000,000, GST exemption fully allocated.
25 years per generation, three generations, 6% return, no distributions.
State rate 16%, reaching the outright path but not the trust.

Calculation path

1
The inclusion ratio is 1 − 10M/10M = 0, so no GST is due at funding or on distributions.
2
The trust compounds at 6% for 75 years: $10m × 1.06⁷⁵ = $790.6m.
3
The outright path pays 40% federal at each generation, then 16% state on what is left.
4
After three handovers the outright path is worth $101.2m.
5
The dynasty structure is worth $689.4m more — the transfer tax that never had to be paid.

Result

$790.6m in trust · $101.2m outright · $689.4m advantage.

Interpreting the result

The inclusion ratio is the whole game. At zero the trust never pays GST, on distributions or on termination; at 0.5 half of every distribution carries the 40% tax. Allocation is a one-time decision made when the trust is funded, and it is usually irrevocable — which is why the exemption is worth more inside a dynasty trust than almost anywhere else.

Assumptions & limitations

Federal GST and estate tax at 40%, state estate tax applied after the federal slice.

A constant total return and a constant distribution rate; no volatility drag.

The trust is outside every estate; the outright path passes through one at each generation.

State treatment is a single rate, applied either to the trust at each generation or only to the outright path.

Frequently asked questions

What is an inclusion ratio?

The share of a trust that is subject to GST. Allocating exemption equal to the funding value drives it to zero, and the trust is then GST-exempt for its whole life.

Can a dynasty trust last forever?

In some states, yes. Others apply a rule against perpetuities, which caps the term. The model lets you set the number of generations rather than assume perpetuity.

Why does the state line matter?

Some states tax trusts at each generation regardless of the federal GST position. That erodes the dynasty advantage, and in a high-tax state it can erase much of it.

What if I cannot allocate the full exemption?

The inclusion ratio rises and every distribution carries GST on that share. The exemption slider shows the cost of leaving it unallocated.