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Illinois Estate Tax Calculator

Illinois has its own state estate tax with a $4,000,000 exemption, separate from the federal estate tax. This estimator screens both.

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Does this estate need probate?

Estate tax is only one question. Answer a few more to see whether Illinois probate is likely and what to do next.

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What This Calculator Screens For in IllinoisA triage screen, not a tax return

For Illinois estates, the first triage question is whether the taxable estate exceeds the state's $4,000,000 exemption. An estate above that amount can owe Illinois estate tax even when it is below the federal threshold, so this tool screens for both the state and the federal exposure.

Probate questions and estate-tax questions are not the same thing. A family can have a probate problem with no tax issue, or a tax-sensitive estate that still transfers efficiently through trust planning.

What the screen looks atState estate-tax status, the federal threshold, and return context

Illinois State Estate Tax Applies

Illinois imposes its own state estate tax with a $4,000,000 exemption, separate from the federal estate tax. This tool screens both the state and the federal exposure.

Federal Threshold

The current screen uses a federal estate-tax exclusion amount of $15 million per person for 2026.

Return Context

Even when no tax is likely due, larger estates may still need more careful return and planning review than a rough calculator can provide.

Frequently Asked Questions

Does Illinois have a state estate tax?
Yes. Illinois imposes its own state estate tax with a $4,000,000 exemption, separate from the federal estate tax. The estimator on this page screens both the state and the federal exposure.
What federal threshold does this Illinois calculator use?
For deaths in 2026, this calculator uses a federal estate-tax exclusion amount of $15 million per person as the starting screen for whether deeper tax review may be needed.
Does every large estate owe federal estate tax?
No. Deductions, valuation issues, marital planning, charitable transfers, and the composition of the estate can all change the taxable amount. The calculator is a screening tool, not a filed return.
Is this the same as preparing Form 706?
No. Form 706 is the federal estate tax return. This estimator is only intended to help decide whether federal estate-tax review may be relevant before a more detailed analysis begins.

Information current as of May 31, 2026

Settled Estate is not a law firm, and this content is for informational purposes only and does not constitute legal advice. Probate laws and procedures in Illinois can change. Consult with a qualified attorney for advice specific to your situation. Full disclaimer.