About the 529 State Tax Deduction Calculator
This 529 state tax deduction calculator estimates how much state income tax you save by contributing to a 529 college savings plan. Pick your state’s rule — or enter your own state’s limit — then your filing status, how much you contribute for each child and your state marginal income tax rate. The calculator applies the annual deduction cap, tells you how much of your contribution is deductible this year, and shows any excess you can carry forward to future years.
More than thirty states give residents a deduction or credit for 529 contributions, usually only for the state’s own plan, and the rules differ a lot: some cap the deduction per tax return, some per beneficiary or per account, some allow unlimited carryforward, and a few give a tax credit instead. That makes it worth checking before you decide how much to put in before December 31 and which plan to use.
Built-in presets cover Illinois, Michigan, Georgia, Ohio, Virginia and Wisconsin using limits published by each state or its official 529 program for the 2026 tax year. For any other state, choose a custom deduction or credit and enter the figures from your state’s plan disclosure. Savings are estimated as the deduction times your marginal rate, which is a close approximation for flat-tax states and for most filers in graduated-rate states. There is no federal deduction for 529 contributions.
With the default inputs, the estimated state tax savings this year is $594. Change any value above to recalculate instantly.
How to use the 529 state tax deduction calculator
- 1Choose your state’s rule, or a custom deduction or credit for any other state.
- 2Select your filing status and number of beneficiaries.
- 3Enter how much you will contribute for each beneficiary this year.
- 4Enter your state marginal tax rate (or the credit rate and cap).
- 5Read the tax savings, and check the table to compare how other state rules treat the same contributions.
Formula and method
The deductible amount depends on how your state applies its cap. A per-return limit (Illinois, Michigan) caps the total of all your contributions; a per-beneficiary or per-account limit (Georgia, Ohio, Virginia, Wisconsin) applies separately to each child, so families with several accounts can deduct more. Some limits double for married couples filing jointly. Anything above the cap is either carried forward to future years (Ohio, Virginia) or gets no state benefit.
Tax savings are estimated as the deduction multiplied by your state marginal income tax rate — the rate on your last dollar of income. In flat-tax states this is exact; in graduated-rate states it is accurate as long as the deduction does not push you into a lower bracket. Credit states reduce your tax directly by a percentage of contributions, often with a maximum per return.
- limit
- State cap per return, per beneficiary or per account
- rate
- Your state marginal income tax rate
Worked examples
Illinois couple, $6,000 each for two children
Illinois allows up to $20,000 per joint return, so all $12,000 is deductible. At Illinois’ 4.95% flat rate that saves $594 — an immediate 4.95% return on the money.
Georgia single parent, $10,000 for one child
Single filers in Georgia can deduct $4,000 per beneficiary. At a 5% marginal rate that saves $200; the other $6,000 receives no Georgia deduction this year.
Ohio grandparent, $10,000 to one grandchild
Ohio caps the deduction at $4,000 per beneficiary per year, saving $120 at a 3% marginal rate. The remaining $6,000 carries forward and can be deducted over the next years until it is used up.
Credit state: 20% credit capped at $1,500
A 20% credit on $5,000 is $1,000, under the $1,500 cap, so the tax bill falls by $1,000 — a 20% instant return.
Frequently asked questions
Are 529 contributions tax deductible?+
Not on your federal return. Many states, however, let residents deduct contributions (or claim a credit) on their state income tax return, usually only for contributions to the state’s own 529 plan. A handful of states offer a deduction for any state’s plan.
Do I have to use my own state’s 529 plan?+
No — you can use any state’s plan. But in most states with a tax break you only get the deduction or credit if you contribute to your home state’s plan, so compare that benefit with the fees and investment options of other plans.
Can grandparents claim the 529 state tax deduction?+
In many states yes: the deduction often goes to whoever contributes, not just the account owner. Ohio, for example, gives contributors up to $4,000 per beneficiary a year. Check your own state’s rules, since some limit the deduction to the account owner.
What is a 529 deduction carryforward?+
Some states, such as Ohio and Virginia, let you deduct contributions above the annual cap in later years until the whole amount has been deducted. That makes a large lump-sum contribution more tax-efficient than it first appears.
Is there a deadline for the state 529 deduction?+
Most states require contributions by December 31 of the tax year, but a few allow contributions made until the April tax-filing deadline to count for the prior year. Check your plan’s rules before relying on a late contribution.
Do I have to pay the deduction back if I withdraw the money?+
Often yes, if the withdrawal is not for qualified education expenses or you roll the money to another state’s plan. Many states “recapture” the earlier deduction by adding it back to your taxable income.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.
Sources
- Bright Start (Illinois State Treasurer) — Illinois deduction disclosure
- MI 529 (MESP) — Michigan tax benefits
- Path2College 529 Plan — Georgia tax deduction
- Ohio 529 CollegeAdvantage — Ohio tax deduction
- Virginia Tax — Deductions (Virginia529 contributions)
- Edvest 529 (Wisconsin) — 2026 state tax deduction