Illinois Estate Tax Calculator
Illinois levies a state estate tax that applies once the taxable estate exceeds its exemption.
Direct answer
Illinois has a state estate tax in 2026 with a $4,000,000 exemption and a top rate of 16.0%. The federal estate tax is calculated separately and applies above the $15M exemption (OBBBA, P.L. 119-21). Source: 35 ILCS 405/2 (no state portability) (2026; retrieved 2026-08-11).
Illinois Estate Tax Calculator — Calculation Summary
| Input / parameter | Value |
|---|---|
| State | Illinois |
| 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.
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)
Related tools & comparisons
- Federal estate tax calculator — the $15M exemption and 2026 numbers
- Gift tax calculator — annual $19,000 exclusion and lifetime exemption use
- Step-up in basis calculator — what heirs' cost basis resets to
- Safe-zone planner — how much can pass free of estate tax
- Relocation planner — compare estate tax after moving to a no-tax state
- No-tax states list — the 33 states without estate or inheritance tax
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
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.