How much can I deduct for a 529 plan in Illinois?

Illinois lets individual filers deduct up to $10,000 in 529 contributions per year, and married couples filing jointly can deduct up to $20,000. Contributions above the cap are not deductible and cannot be carried forward in Illinois.

Which Illinois 529 plans qualify for the deduction?

Contributions to Illinois-sponsored plans, Bright Start and Bright Directions, qualify for the state income tax deduction. Contributions to another state's 529 plan do not earn the Illinois deduction.

What is the Illinois income tax rate used for 529 savings?

Illinois has a flat individual income tax rate of 4.95%. Your 529 tax savings equal your deductible contribution multiplied by that 4.95% rate, since the deduction lowers your Illinois taxable income.

Is the Illinois 529 benefit a deduction or a credit?

It is a deduction, not a credit. It reduces the income Illinois taxes rather than directly reducing your tax bill dollar-for-dollar, so its value equals the contribution times the 4.95% flat rate.

Can I carry forward 529 contributions above the cap in Illinois?

No. Unlike some states, Illinois does not allow you to carry forward contributions that exceed the annual deduction cap. To maximize the benefit, spread large contributions across multiple tax years.

Illinois 529 Plan Tax Benefit Calculator

Email me this result

Get this tool's output sent to your inbox, plus one useful tool a week. No spam, unsubscribe any time.

Saving for college in an Illinois Bright Start or Bright Directions 529 account comes with a state income tax deduction that many savers leave on the table. This calculator shows exactly how much you save on your Illinois taxes for a given contribution, capped at the state’s annual deduction limit.

How it works

The Illinois benefit is a deduction against the state’s flat income tax. Your savings are the deductible portion multiplied by the 4.95% rate:

deductible = min(contribution, cap)
cap        = $10,000 (single)  or  $20,000 (married filing jointly)
tax saving = deductible × 4.95%

Because Illinois has a single flat income tax rate, the math is simple and does not depend on your income bracket. Only contributions to Illinois-sponsored plans qualify, and any amount over the cap is not deductible and cannot be carried forward.

Example

A married couple contributing $25,000 to Bright Start can only deduct the $20,000 joint cap. Their Illinois tax saving is $20,000 × 4.95% = $990. The extra $5,000 earns no Illinois deduction this year and cannot be carried forward.

Notes

This estimates the state income tax saving only. The bigger long-term benefit is tax-free growth and tax-free qualified withdrawals at the federal and state level, which this tool does not project. Confirm the current caps with the Illinois plan, as limits can be adjusted.