The larger federal estate-tax exclusion does not eliminate Illinois estate tax. In 2026, the federal basic exclusion is $15 million per person, while Illinois uses a separate $4 million exclusion. A family can be below the federal limit and still need substantial Illinois planning.
The federal legislation commonly called the One Big Beautiful Bill changed the federal rules beginning in 2026. It did not turn the Illinois threshold into the federal amount.
Compare the rules for the relevant year
The IRS estate-tax page lists a $15 million federal filing threshold for 2026. Prior adjusted taxable gifts and other applicable items matter in deciding whether a return is required; the threshold is not simply a comparison to the property left in the probate estate.
Illinois’s separate framework appears in 35 ILCS 405/2. Its exclusion and computation require a state-specific analysis.
“Permanent” legislation means the prior scheduled reduction was removed. It does not mean Congress can never amend the law again. Plans should remain workable as assets and family circumstances change.
A federal zero does not answer the Illinois question
A hypothetical $5 million tentative taxable estate with no adjusted taxable gifts and all property having Illinois situs produces an estimated Illinois tax of $285,714 using our calculator. That example assumes allowable deductions have already been reflected other than Illinois estate tax; it is not an estimate for every household with $5 million of assets.
See the full Illinois estate-tax examples before comparing the figure with your own circumstances.
A useful first step is to identify the assets that actually belong in the estate, including potentially includible insurance and trust property. Our asset inventory guide explains the distinctions.
Married couples need separate federal and state decisions
Federal portability can preserve a deceased spouse’s unused exclusion for a surviving spouse when the requirements are met. It requires an election and return; it should not be assumed from the fact of marriage. The statutory rules are in Section 2010.
Illinois does not provide comparable state portability. Marital and QTIP trust planning should therefore address both deaths and the assets expected to remain with the survivor.
The right choice can depend on liquidity, family beneficiaries, access to principal, and income-tax basis. A larger federal exclusion does not resolve those questions.
Review a specific plan before changing ownership
Start with current assets, ownership, insurance, debts, and prior gifts. Then compare the proposed plan with the existing one.
A revocable trust, LLC, or land trust should not be treated as an automatic estate-tax reduction. The rights retained, interests transferred, valuations, and applicable law determine the tax result. Likewise, an outright gift may reduce access to property the donor later needs.
Use the Illinois estate tax calculator to organize a preliminary estimate, then schedule a planning consultation to discuss the assumptions and available choices. The goal is a plan that addresses the family’s actual state and federal exposure.