Estate Tax — Illinois
Illinois Estate Tax Calculator 2025
Illinois has a separate estate tax with a $4,000,000 exemption — far below the federal $13,990,000. Calculate your combined liability.
Not tax advice.Illinois estate tax computation is complex — the state uses a “qualified gross estate” with a credit calculation. This calculator provides an estimate of effective tax, not the precise Illinois Revenue Form IL-700. Consult an estate attorney or CPA licensed in Illinois.
Estate Details
Total value of all assets: real estate, investments, retirement accounts, life insurance proceeds, business interests
Only IL and MA estate tax are currently supported. More states coming soon.
2025 Exemptions
Federal: $13,990,000 per person
Illinois: $4,000,000 per person
Estate Tax Estimate
Gross Estate$5,000,000
Federal Exemption−$5,000,000
Federal Taxable Estate$0
Federal Estate Tax (40%)$0 (below exemption)
Illinois Estate Tax
State Exemption−$4,000,000
State Estate Tax−$96,000
Total Estate Tax$96,000
Estate Passing to Heirs$4,904,000
Effective rate: 1.9% of gross estate
Illinois estate tax — key facts
Illinois vs. Federal comparison
| Factor | Illinois | Federal |
|---|---|---|
| 2025 Exemption | $4,000,000 | $13,990,000 |
| Top rate | ~16% | 40% |
| Portability | No | Yes |
| Filing deadline | 9 months from death | 9 months from death |
Who owes IL estate tax?
Illinois residents with estates exceeding $4M, plus non-residents who own Illinois real estate or business interests. The IL estate tax applies to:
- ›IL residents — all worldwide assets
- ›Non-residents — IL-situated assets proportionally
- ›Married couples — no portability without trust planning
- ›Farms and closely-held businesses — special use valuation available
Illinois estate tax FAQ
What is the Illinois estate tax exemption in 2025?
Illinois has a $4,000,000 estate tax exemption per person in 2025. This is significantly lower than the federal $13,990,000. Estates between $4M and $13.99M may owe Illinois estate tax but no federal estate tax. Illinois is one of only 12 states (plus DC) with its own estate or inheritance tax.
What are Illinois estate tax rates?
Illinois estate tax rates are graduated from approximately 0.8% to 16% on the taxable estate. The Illinois Department of Revenue uses a computational tax on the qualified gross estate. Estates just above the $4M threshold face lower effective rates; very large estates approach the 16% cap.
Does Illinois allow estate tax portability?
No — unlike the federal system, Illinois does NOT allow portability of the unused exemption to a surviving spouse. For married couples in Illinois, proper trust planning (typically a 'bypass trust' or 'credit shelter trust') is critical to preserve both spouses' $4M exemptions, potentially doubling the exemption to $8M.
When is Illinois estate tax due?
The Illinois estate tax return (Form IL-700) is due within 9 months of the date of death. An extension of up to 6 months can be requested for filing, but interest accrues on any unpaid tax. The Illinois estate attorney general's office administers the tax.
Can Illinois estate tax be reduced by planning?
Yes — common strategies include: (1) Bypass trusts to use both spouses' exemptions. (2) Irrevocable life insurance trusts (ILITs) to keep life insurance proceeds outside the estate. (3) Gifting within annual exclusion limits ($18,000/person in 2025). (4) Qualified personal residence trusts (QPRTs). (5) Family limited partnerships. All require professional estate planning counsel.
Get Illinois estate planning help
An estate attorney can structure your estate to minimize or eliminate Illinois estate tax. Find Illinois estate attorneys through FindLaw or Martindale-Hubbell.