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Estate Tax in Illinois: Complete Guide 2026

Tax information is for educational purposes only and does not constitute tax advice. Consult a licensed estate planning attorney for your specific situation.

Illinois imposes a state estate tax with an exemption of approximately ~$4.00 million per person and a graduated rate structure reaching a top rate of ~16.00%. Illinois’s exemption is moderate compared to other estate tax states — higher than Oregon and Massachusetts, but lower than New York and Connecticut. For Illinois residents, particularly those in the Chicago metropolitan area where real estate values are significant, understanding the estate tax is an important component of comprehensive financial planning.

Illinois Estate Tax Rates and Exemption (2026)

Parameter	Projected 2026 Level
Estate tax exemption	~$4.00 million
Lowest effective rate	~0.80%
Highest marginal rate	~16.00%

Illinois Estate Tax Rate Schedule

Illinois uses a graduated rate structure similar to the federal estate tax, but with a credit that eliminates tax for estates below ~$4.00 million:

Taxable Estate	Approximate Marginal Rate
$0 — $500,000	~0.80%
$500,001 — $1,000,000	~5.60%
$1,000,001 — $2,000,000	~6.40% to ~8.00%
$2,000,001 — $4,000,000	~8.80% to ~10.40%
$4,000,001 — $6,000,000	~11.20% to ~12.80%
$6,000,001 — $10,000,000	~13.60% to ~15.20%
Over $10,000,000	~16.00%

Estimated Tax by Estate Size

Estate Value	Estimated Illinois Estate Tax
$4,000,000	$0
$4,500,000	~$75,200
$5,000,000	~$178,800
$6,000,000	~$395,200
$8,000,000	~$748,800
$10,000,000	~$1,087,200

Illinois has a soft cliff effect: estates slightly above ~$4.00 million face immediate tax that may seem disproportionate. An estate of ~$4.5 million may owe approximately ~$75,200, which is a ~15% effective rate on the $500,000 excess.

How Illinois Estate Tax Works

Calculation Method

Illinois computes its estate tax by calculating the federal estate tax using pre-2002 federal rates and exemptions, then applying a credit linked to the state’s ~$4.00 million exemption. This method creates an effective tax that applies to the entire estate once the exemption is exceeded, similar to how Massachusetts operates.

No Portability

Unlike the federal system and Hawaii, Illinois does not offer portability of the estate tax exemption between spouses. Each spouse has their own ~$4.00 million exemption, but the surviving spouse cannot claim any unused portion from the deceased spouse. This makes trust planning essential for married couples.

What Is Included in the Illinois Taxable Estate

Illinois follows the federal gross estate definition:

Real property in Illinois
Financial accounts, investments, and retirement accounts
Life insurance proceeds (if the decedent owned the policy)
Business interests in Illinois entities
Tangible and intangible personal property

Illinois allows the unlimited marital deduction and charitable deduction. Assets passing to a surviving U.S. citizen spouse are not subject to Illinois estate tax.

Comparison to Neighboring States

State	Exemption	Top Rate	Portability?
Illinois	~$4.00 million	~16.00%	No
Indiana	None	N/A	N/A
Iowa	Inheritance tax (phasing out)	~6.00%	N/A
Wisconsin	None	N/A	N/A
Missouri	None	N/A	N/A
Kentucky	Inheritance tax	~16.00%	N/A

Illinois is the only state in its immediate region with an estate tax. Indiana, Wisconsin, and Missouri have no estate or inheritance tax, creating potential relocation incentives for Illinois residents with significant estates.

Chicago Metro Real Estate Considerations

The Chicago metropolitan area represents the majority of Illinois’s population and real estate wealth. While Chicago home values are more moderate than coastal cities, they can still push estates above the threshold:

Neighborhood/Area	Median Home Value (Est.)
Lincoln Park	~$850,000
North Shore suburbs	~$700,000 to ~$1,500,000
Naperville/Hinsdale	~$550,000 to ~$1,200,000
Chicago overall	~$325,000

A homeowner in the North Shore suburbs with a $1.2 million home, $1.5 million in retirement accounts, a $500,000 life insurance policy, and $800,000 in other assets would have a ~$4.0 million estate right at the exemption threshold.

Tips for Minimizing Illinois Estate Tax

Use a credit shelter trust. Since Illinois does not offer portability, a credit shelter (bypass) trust is essential for married couples. Without one, the first spouse’s ~$4.00 million exemption is wasted, and the surviving spouse’s entire estate is measured against a single ~$4.00 million exemption.
Make lifetime gifts. Illinois does not impose a state gift tax. Annual exclusion gifts of approximately ~$19,000 per recipient per year systematically reduce the estate without state tax consequence.
Remove life insurance from the estate. An irrevocable life insurance trust (ILIT) removes policy proceeds from the taxable estate. For a family with a $500,000 policy, this can be the difference between owing tax and staying below the exemption.
Maximize charitable bequests. Charitable gifts reduce the Illinois taxable estate dollar-for-dollar. Charitable remainder trusts and donor-advised funds can combine estate tax savings with income tax benefits.
Consider the impact of retirement accounts. IRAs and 401(k)s are included in the taxable estate. Converting traditional IRAs to Roth IRAs reduces the estate value (after paying income tax on the conversion) while providing tax-free income to beneficiaries.
Evaluate domicile change. Indiana, Wisconsin, and Florida have no estate tax. A genuine relocation eliminates Illinois estate tax on intangible property, though Illinois real estate remains subject to tax.

Key Takeaways

Illinois’s estate tax exemption is approximately ~$4.00 million with rates reaching ~16.00%
Illinois does not offer portability, making credit shelter trust planning essential for married couples
The estate tax applies only to the excess above the exemption, but the effective rate on amounts just above the threshold can feel steep
Illinois is the only state in the Midwest with an estate tax; all neighboring states lack one
Lifetime gifting is effective since Illinois has no state gift tax
Chicago-area real estate values can push moderate-wealth estates above the exemption

Next Steps

Understand the federal framework at Federal Estate Tax: Complete Guide 2026
Compare sales tax at Sales Tax in Illinois 2026
Read the full state guide at Taxes in Illinois: State Tax Guide 2026
Calculate your tax position at Tax Bracket Calculator 2026
Get professional help: Hire a Tax Professional