50 States + D.C. coverage 2026 $15M federal exemption Statute-cited figures Editorial review 2026

Estate Tax Planning Simulator

Compare two scenarios: no planning versus electing portability and the marital deduction. The difference shows the value of the post-death elections that many simple calculators ignore.

Scenario A — No planning

$1,386,800
federal $0 · state $1,386,800

Scenario B — With planning

$1,386,800
portability + marital deduction elected
You could keep
$0
more for heirs (0% less tax)

Scenario B models electing portability (DSUE) of the deceased spouse's unused $15M exclusion and the unlimited marital deduction — the two levers most simple calculators ignore. A credit-shelter (bypass) trust can lock in the savings. State amounts are model estimates.

Informal estimate only — not legal or tax advice. Figures cite federal statute (IRC § 2010, OBBBA 2025) and each state's Department of Revenue. Tax laws and exemption amounts change yearly; confirm the current rule with the IRS, your state agency, or a licensed estate attorney or CPA before relying on any number.

How this calculator works

This estate tax simulator compares the tax bill in two scenarios. Scenario A assumes no portability is elected and the marital deduction is not used. Scenario B assumes the surviving spouse elects portability of the deceased spouse’s unused $15M exclusion and uses the unlimited marital deduction. The difference is the first layer of tax savings available to most married couples — before trusts, lifetime gifts, or other advanced strategies.

Calculation method & sources

  • Marital deduction: IRC § 2056 permits an unlimited deduction for property passing to a surviving U.S.-citizen spouse, deferring tax until the second death.
  • Portability (DSUE): IRC § 2010(c)(5). The surviving spouse can add the deceased spouse's unused exclusion, raising the combined federal shelter to $30M in 2026.
  • State rules: Each state’s estate tax rules are sourced to its Department of Revenue or statute. Some states (e.g., Massachusetts) do not recognize portability, making credit-shelter trusts more important.

How to interpret your estate tax planning result

  • Scenario A is intentionally pessimistic — it shows what happens if no elections are made.
  • Scenario B shows the savings from two automatic or election-based benefits: the marital deduction and portability.
  • The “tax saved with planning” is the minimum a married couple should capture; advanced planning (bypass trusts, ILITs, gifting) can save far more.
  • If you are single, Scenario A and Scenario B will usually be identical because there is no spouse to receive the marital deduction or DSUE.

Related guides

Frequently asked questions

How much does portability save?
Portability can save up to the full value of the deceased spouse's unused $15M exemption taxed at 40%, or roughly $6M in federal tax for a large estate. The simulator shows the exact amount for the estate size you enter.
What is a credit-shelter or bypass trust?
A credit-shelter trust is an irrevocable trust that holds the first spouse’s assets up to the exemption amount. It removes those assets from the surviving spouse’s taxable estate while still providing income or access.
Should every married couple elect portability?
Almost always, yes. Electing portability on Form 706 preserves the deceased spouse’s unused exemption for future use. It is inexpensive insurance even when no tax is currently due.
Does the marital deduction eliminate estate tax forever?
No. The marital deduction only defers tax until the surviving spouse dies. Without further planning, the second estate may owe tax on the combined assets.
Not legal or tax advice. This estimate follows the federal and state statutes referenced on this page but cannot capture every factor (trusts, business valuation, charitable deductions, prior gifts, state add-backs).