You searched for an Illinois RSU tax rate and found conflicting flat percentages — you want the real combined hit on vest FMV including Illinois state tax, federal, and FICA, especially as a Chicago resident comparing offers to Wisconsin or Indiana.
In plain terms
Gather before you start
- IL residency for year.
- confirmation and IL on pay stub.
- IL wage boxes.
- Illinois DOR rate for filing year.
- tax calculator with Illinois selected.
How the tax works
Searches for an tax rate in Illinois usually mean you want one percentage to plan cash for a . Illinois applies a flat state income tax rate to taxable income including wages per Illinois DOR guidance for your filing year — simpler than progressive states like California or New York, but still stacked on top of federal tax and FICA.
Federal progressive income tax and FICA apply separately on . FICA runs nationwide on wages with Social Security stopping at the annual wage base and Medicare applying to the full amount. Employer supplemental on equity often uses flat federal methods that can under- compared with your true stacked on salary plus .
Chicago does not add a separate city wage income tax on wages the way New York City does — Illinois state income tax is the main state layer for Chicago residents and suburban employees. Trading, fintech, and healthcare vests in the metro area follow the same Illinois wage treatment when IL-sourced.
Moving from Illinois to a no-tax state mid-year triggers a part-year Illinois return on pre-move connected income. The Wisconsin–Illinois reciprocal agreement may affect for border commuters — but an Illinois resident generally reports IL-sourced wages including vests on the Illinois return. Remote IL residents working for out-of-state employers still typically owe Illinois tax on wages as resident income.
The practical planning number is a combined estimate: Illinois flat state rate per current DOR publications times estimated taxable income, plus federal plus remaining FICA on the . Use the Illinois tax guide for mechanism detail and the tax calculator with Illinois selected for a stacked-income estimate.
What to check on your end
- IL state on pay stub.
- IL wage and tax boxes.
- Federal Box 1 and .
- IL flat rate per DOR pub for filing year.
- Federal gap vs .
- Move date if part-year IL.
- Calculator output vs pay stub.
1 more checklist item
- Illinois DOR pub for current year.
Assuming Illinois flat tax means RSU vest withholding covers your full tax bill
What to pull from your files
- IL pay stub.
- IL boxes.
- confirmation.
- IL estimated tax if made.
- Move docs if part-year.
Chicago employee with annual RSU stack
Illustration only, not your tax situation.
Questions people ask
- What is the RSU tax rate in Illinois?
- IL flat state rate on wages plus federal marginal tax plus FICA — check Illinois DOR publications for the current flat rate for your filing year.
- Are RSUs taxed in Illinois?
- Yes — is IL wage income for typical IL residents.
- Illinois vs Indiana RSU tax?
- Both states tax wages including vests — rates and reciprocity rules differ; see state comparison tools.
- IL RSU supplemental withholding?
- Employers IL and federal on — federal supplemental may still under- vs .
- Moved from Illinois to Florida?
- IL may tax pre-move connected income. Post-move FL vests avoid FL state income tax for typical residents.
When a CPA is worth it
- Part-year IL resident with equity from two states.
- Employer withheld wrong state on IL resident .
- Multi-state remote work allocation.
- Reciprocal state commuter questions.
Sources and notes
Primary tax claims on this page are supported by the official and secondary sources below. Broker and software links describe reporting mechanics — confirm rules against IRS or state guidance.
Illinois flat individual income tax on vest wages; confirm current IL DOR rate.
- Illinois DOR — Individual Income Tax
Illinois Department of Revenue · Official
Illinois individual income tax including flat rate structure.
- IRS Publication 525 — Taxable and Nontaxable Income
Internal Revenue Service · Official
Covers compensation income from stock-based pay, including restricted property under section 83.
Related calculators
- RSU Tax Calculator
Model federal and state taxes on your RSU vest, compare withholding to estimated tax, and see what you may keep.
- RSU Withholding Gap Calculator
Focus on the gap between what your employer withholds on RSU vests and what you may owe when everything is reconciled.
- RSU State Tax Comparison Calculator
Run the same RSU vest through different state assumptions to see how location may change estimated tax.
Related pages
- Illinois RSU Tax Guide
Illinois taxes RSU vest income as wages; part-year residency applies if you move in or out.
- RSU Tax Rate in Colorado
Colorado applies flat state income tax to RSU vest wages — federal marginal tax and FICA still apply on top.
- RSU Taxes When Moving States
Moving mid-year can mean more than one state has a claim on part of your compensation — planning beats guessing.
- RSU Effective Tax Rate Explained
There is no flat RSU tax rate — effective tax on vest FMV includes federal, FICA, and state components that change with your total income.
- RSUs and Marginal Tax Rates
RSU vest income stacks on salary — your marginal rate on that vest slice may be higher than flat withholding.
For learning, not filing
VestingTax.com is not a CPA firm or tax preparer. Grants, employers, and states all differ. Use the cited IRS and state sources above, your own documents, and a qualified tax professional before you make decisions from this guide.