ILLINOIS INHERITANCE AND ESTATE TAX · DEATHS IN 2026
Illinois inheritance and estate tax calculator
Illinois has no inheritance tax, but it taxes estates over $4,000,000. That amount is a threshold, not a credit, and the tax comes from the Attorney General's calculation rather than a rate table. On a $5,000,000 estate with nothing left to a spouse or charity, Illinois estate tax is $285,714, 5.71% of the estate. No federal estate tax is due on an estate under the $15,000,000 federal exclusion.
Tax on the estate
- Total estate and inheritance tax
- $285,714.00
- Federal estate tax
- $0.00
- Illinois estate tax
- $285,714.00
- Illinois exemption
- $4,000,000.00
Illinois and federal estate tax by size of estate
The tax on an estate with nothing left to a spouse or charity and no lifetime taxable gifts. Federal tax is figured after deducting the state tax.
| Estate | Federal estate tax | Illinois estate tax |
|---|---|---|
| $4,000,000 | $0 | $0 |
| $5,000,000 | $0 | $285,714 |
| $10,000,000 | $0 | $926,923 |
| $15,000,000 | $0 | $1,609,310 |
| $25,000,000 | $2,804,552 | $2,988,620 |
Illinois inheritance and estate tax questions
Does Illinois have an inheritance tax?
No. Illinois has no inheritance tax, but it taxes estates over $4,000,000. That amount is a threshold, not a credit, and the tax comes from the Attorney General's calculation rather than a rate table.
How much is Illinois estate tax on a $5,000,000 estate?
With nothing left to a spouse or charity, a $5,000,000 estate owes $285,714 of Illinois estate tax and a $10,000,000 estate owes $926,923. Neither owes federal estate tax, which starts above $15,000,000.
Can a surviving spouse use an Illinois exclusion left unused?
No. Illinois does not allow portability of a deceased spouse's unused exclusion. Unless the first estate uses its exclusion, through an Illinois QTIP election or a marital plan, the unused part is lost.
What the calculator leaves out
- The calculator assumes the decedent lived in the state and all property is there; property elsewhere reduces the tax by apportionment.
- Illinois publishes no formula; the calculator rebuilds the Attorney General's calculation from its official examples, which it reproduces to the dollar by dropping cents as the official calculator appears to.
- Illinois does not allow portability of a deceased spouse's unused exclusion.
- Gift tax paid on lifetime gifts is not subtracted.
- The deduction for state death taxes (IRC 2058) counts the state estate tax and the entered heir's inheritance tax, not inheritance tax other heirs pay.
- A deceased spouse's unused exclusion (portability) is not added.
Enter the estate's value after debts and expenses. What you leave to a spouse or to charity is deducted in full, as the marital and charitable deductions allow for a U.S.-citizen spouse and a qualifying charity. Lifetime taxable gifts are added back for the federal tax. Federal tax uses the 2026 exclusion of $15,000,000 and rates up to 40%, after deducting state death taxes. These are estimates, not legal advice.