Cook County voters will decide this November whether they support a 3% income tax surcharge on millionaires, according to an advisory referendum analysis published by the Illinois Policy Institute. The ballot measure proposes splitting the new revenue equally between property tax relief and public education funding. However, the vote is non-binding and won't trigger any actual policy change, regardless of the outcome.
The ballot question asks whether Illinois should adopt what's called the Millionaire Amendment for Property Tax Relief and Education, which would add a 3% income tax surcharge only on millionaires and dedicate half the revenue to property tax relief for residential and commercial taxpayers while directing the other half toward improving state funding for public schools. The language mirrors a constitutional amendment that didn't pass in the Illinois House earlier this year and resembles a previous statewide ballot question from 2024. Notably, the Cook County ballot question doesn't specify whether the additional 3% would apply only to income above $1 million or to all income for taxpayers whose earnings exceed $1 million—a distinction that drew heavy criticism when Gov. J.B. Pritzker proposed in 2019 raising the state income tax to 7.95% from 4.95% on all income for anyone earning more than $1 million.
The report finds that previous analysis of the proposal and Illinois' state finances shows the massive tax hike would come up more than $2 billion short of being able to provide Illinoisans with any property tax relief. That shortfall exists because the state projects future budget gaps exceeding $3.8 billion, and the current pension funding plan falls short of required contributions by more than $5 billion, according to the plan's own actuaries. When lawmakers last put a binding statewide measure like this to voters in 2020, they proposed six new tax brackets ranging from 4.75% to 7.99% and expected to increase income taxes by $3.7 billion—but the proposal failed at the polls.
The report explains that implementing any millionaires tax would require amending the Illinois Constitution because the state has a constitutionally protected flat income tax. Removing that protection would open the door to numerous potential tax increases beyond the initial proposal. Enacting such a measure would let lawmakers create multiple tax brackets with rising marginal rates, and even if legislation initially targeted only the highest earners, nothing would stop expansions over time—Illinois has repeatedly enacted "temporary" income tax increases that became permanent. Eliminating the flat-tax requirement would also allow lawmakers to treat different types of income differently, making a retirement income tax—currently banned in Illinois—more likely, as state Treasurer Michael Frerichs admitted when legislators tried to pass a graduated income tax in 2020.
The earliest a constitutional amendment could appear on the ballot statewide would be the November 2028 general election. Because the Cook County referendum is advisory only, it won't change the state constitution or alter the flat tax rate, making this vote essentially a temperature check on voter sentiment rather than a binding policy decision.