Does Illinois have an estate tax? Yes, it does. Illinois is one of about a dozen states that still collects its own estate tax. It is separate from the federal estate tax.
The Illinois tax only applies to larger estates, though. The current Illinois exemption is $4 million per person. That number is much lower than the federal exemption of $15 million in 2026. As a result, some Illinois families who owe nothing to the IRS may still owe Illinois. If you are planning ahead or settling a loved one’s estate right now, this guide walks you through the basics in plain English.
Does Illinois Have an Estate Tax? The Short Answer
So, does illinois have an estate tax that most families need to worry about? In most cases, no. An estate tax is a tax on everything a person owns when they die. That includes a home, bank accounts, retirement accounts, life insurance, and investments. The tax is paid from the estate before heirs receive their share.
Illinois only taxes estates worth more than $4 million. This rule comes from the Illinois Estate and Generation-Skipping Transfer Tax Act, found at 35 ILCS 405. Most Illinois estates fall well below that line. As a result, most families will never pay this tax.
However, $4 million is not as far away as it sounds. For example, a paid-off Chicago-area home, a 401(k), and a large life insurance policy can add up quickly. Life insurance counts if the person who died owned the policy.
How the Illinois Estate Tax Works: Exact Rules and Figures
The Illinois exemption is set at a flat $4 million. It is not adjusted for inflation. It has stayed the same for over a decade. Meanwhile, the federal exemption keeps rising. The gap between the two keeps growing as a result.
Illinois rates are graduated and top out at 16%. However, there is a catch many people miss. If an estate goes over $4 million, the tax is figured on the whole taxable estate, not just the amount above the line. For example, an estate worth $4.2 million can owe far more than 16% of $200,000. Because of the way the math works, the jump just above $4 million can feel steep. This is often called the Illinois “cliff.”
Illinois also does not allow “portability.” Portability lets a surviving spouse use the unused exemption of the spouse who died. The federal system allows it. Illinois typically does not. As a result, married couples cannot simply combine two Illinois exemptions without planning ahead.
| Rule | Illinois | Federal (2026) |
|---|---|---|
| Exemption per person | $4,000,000 | $15,000,000 |
| Top tax rate | 16% | 40% |
| Indexed for inflation? | No | Yes |
| Portability for spouses? | No | Yes |
| Return and due date | Form 700, 9 months after death | Form 706, 9 months after death |
| Inheritance tax? | No | No |
Some things are not taxed at all. In most cases, anything left to a surviving spouse passes tax-free. This is called the marital deduction. Gifts to qualified charities are also typically deducted. In addition, Illinois has no inheritance tax. An inheritance tax is charged to the person who receives the money. Illinois does not do that.
Who Files, and When
If the estate is over $4 million, the executor files Illinois Form 700. An executor is the person named in a will to wrap up the estate. If there is no will, the court appoints someone to do this job. The return and payment are generally due 9 months after the date of death.
The return is filed with the Illinois Attorney General’s office. The payment typically goes to the Illinois State Treasurer. Illinois also asks for a copy of a federal Form 706 with the state return. This is true even when no federal tax is owed. Many executors fill out the federal form just for Illinois purposes.
The IRS estate tax page explains the federal side. Keep in mind the two systems have different rules and different limits.
What to Do Next
If you are settling an estate now, start with a simple list. Write down every asset and its value on the date of death. Include the home, accounts, retirement plans, and life insurance. Then add up the total. If the total is clearly under $4 million, the Illinois estate tax most likely does not apply.
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If the total is close to or over $4 million, slow down. The Illinois cliff makes small numbers matter. For example, how a home or business is valued can change the tax owed. In this case, check with a licensed Illinois attorney or a tax professional before the 9-month deadline.
If you are planning ahead, there is time to think it through. Many married couples use a “credit shelter” or “bypass” trust. This type of trust can help protect the first spouse’s Illinois exemption. Lifetime gifts and charitable giving may also lower a future estate. Every family is different, so it helps to talk with a professional about your own situation.
Finally, remember that the estate tax and probate are not the same thing. Probate is the court process for settling an estate. An estate can go through probate without owing any tax. Likewise, an estate can owe tax even if most assets skip probate.
Frequently Asked Questions
Does Illinois have an estate tax if my estate is under $4 million?
No. In most cases, estates under $4 million owe no Illinois estate tax. As a result, no Illinois estate tax payment is typically due. However, it is still smart to add up all assets carefully, including life insurance.
Do I have to pay tax on money I inherit in Illinois?
Typically, no. Illinois has no inheritance tax, so heirs do not pay tax just for receiving an inheritance. Any estate tax is paid by the estate first. However, some items, like traditional IRAs, may carry income tax when you withdraw money.
Can my spouse use my Illinois exemption after I die?
Not automatically. Illinois generally does not allow portability, unlike the federal system. For example, couples often use a trust to make sure both $4 million exemptions are used. Check with a licensed Illinois attorney to see what fits your family.
Make Sure Your Plan Actually Works
A will or trust only does its job if the rest of your plan lines up. Two quick checks before you finish:
- Get your state’s exact rules — witnesses, notary, probate cost, and tax thresholds vary by state.
- Beneficiary forms beat your will — make sure your life-insurance beneficiaries are current, because named beneficiaries pass outside your will.
Sources & How to Verify
This guide is built from official sources. Always confirm the exact figure for your state:
- IRS — Estate & Gift Tax: irs.gov
- USA.gov — What to do when someone dies: usa.gov/death
- Uniform Law Commission (probate): uniformlaws.org
- Cornell Legal Information Institute: law.cornell.edu
- Your state’s probate court self-help portal and revenue department for the current statute and dollar figures.
Verified October 2026. Estate figures change — if you spot anything outdated, please contact us.
Related Guides
- Wills by State
- Trusts & Living Trusts by State
- Estate & Inheritance Tax by State
- Plain-English Estate Glossary
Disclaimer. This page is for general information only and is not legal or tax advice. Wills, probate, and estate-tax rules vary by state, county, and situation, and change over time. We are not a law firm, tax advisor, or financial planner, and we assume no liability for accuracy or completeness. For your specific situation — especially an active probate or a tax deadline — verify with your state’s court, statute, revenue department, or a licensed attorney in your state.