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Illinois Estate Tax Calculator

Illinois levies a state estate tax that applies once the taxable estate exceeds its exemption.

Estate tax

Illinois Estate Tax Calculator — Calculation Summary

Input / parameterValue
StateIllinois
Taxable estate$6,000,000
Result
Federal estate tax$0
Illinois state estate tax$210,000
Total estate tax$210,000

Source: 35 ILCS 405/2 (no state portability) (2026).

This is an informal planning estimate only, not legal or tax advice. Confirm all figures with the IRS, your state Department of Revenue, or a licensed estate attorney or CPA before relying on them.

Federal exemption$15M
Illinois exemption$4M
Top state rate16%
State portabilityNo
Federal estate tax$0
Illinois state estate tax$210,000
Total$210,000

Source: 35 ILCS 405/2 (no state portability) (2026)

Administration & filing in Illinois

  • Who pays: The estate pays the tax before distribution to heirs.
  • Where filed: With Illinois's tax authority (typically the Department of Revenue or Taxation), on a state estate/inheritance tax return.
  • Deadline: State returns generally follow the federal estate tax return timeline (IRS Form 706, due ~9 months after death, with a 6-month extension available), but state dates can differ — confirm with the state agency.
  • Citation: 35 ILCS 405/2 (no state portability) (2026)

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 Illinois estate tax calculator combines the latest federal exemption with Illinois's state-specific rules. Illinois levies a state estate tax that applies once the taxable estate exceeds its exemption. Enter your estate size to see the federal tax, the state tax, and the combined total.

Calculation method & sources

  • Federal tax: IRC § 2010(c)(3) exemption of $15M per person and IRC § 2001 graduated brackets.
  • Illinois tax: 35 ILCS 405/2 (no state portability) (2026).

How to interpret your Illinois estate tax result

  • Illinois estate tax applies once the taxable estate exceeds $4,000,000.
  • Top state rate: 16.0%.
  • Illinois does not recognize portability; married couples should consider a credit-shelter trust to use both exemptions.
  • Federal estate tax is calculated separately and may apply above the $15M federal exemption.

Related guides

Frequently asked questions

Does Illinois have an estate tax?
Yes. Illinois has a state estate tax with a $4,000,000 exemption and a top rate of 16.0%.
What is the Illinois estate tax exemption in 2026?
The 2026 Illinois estate tax exemption is $4,000,000 per person.
Does Illinois recognize portability of a deceased spouse's exemption?
No. Illinois does not recognize portability. Married couples often use a credit-shelter (bypass) trust to preserve both exemptions.
Does Illinois have an inheritance tax?
No. Illinois does not levy an inheritance tax.
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).