Wisconsin 529 tax deduction calculator.

How this is calculated

The Edvest 529 tax-benefits page says Wisconsin taxpayers can reduce their 2026 state-taxable income dollar-for-dollar, up to annual limits. The maximum deduction for 2026 is $5,280 per beneficiary for single filers or married couples filing a joint return, or $2,640 per beneficiary for married couples filing separately. Contributions above the maximum may be carried forward as a deduction in future years, subject to the same annual maximum.

The deduction is available to any Wisconsin taxpayer, not only the account owner, so grandparents and other relatives who file in Wisconsin can claim their own gift contributions. On timing, Edvest says Wisconsin taxpayers have until Thursday, April 15, 2027 to contribute to an existing account, or open and fund a new one, to be eligible for the 2026 deduction.

The calculator adds any carryforward you enter to this year's contribution, applies the cap for your filing status (multiplied by the number of beneficiaries), and multiplies the deductible amount by the state tax rate you type in. It does not guess your rate, because that depends on your income. The rest, the part above the cap, is what carries forward.

Worked example

$8,000 for one child, single. $5,280 is deductible for 2026 and $2,720 carries forward.

$8,000 split across two children, married filing jointly. The cap is per beneficiary, so $4,000 each is under the $5,280 cap and all $8,000 is deductible.

$6,000 for one child, married filing separately. Each spouse's cap is $2,640 per beneficiary, so $2,640 is deductible for the spouse who made the contribution and $3,360 carries forward.

Limits of this estimate

We read the Edvest plan site, not a Wisconsin Department of Revenue page, so the figures are the plan administrator's statement of state law. The plan page does not say how rollovers from another state's plan are treated or how a nonqualified withdrawal is recaptured; check the Wisconsin Form 1 instructions for that. The tax saved is only the Wisconsin income tax effect at the rate you enter, and there is no federal deduction for 529 contributions.

Who should check first

If you moved to or from Wisconsin during the year, contribute for someone else, or want to compare Wisconsin with a neighboring state, do the comparison on the state returns, not on plan marketing pages. Spouses filing jointly share one $5,280 cap per beneficiary, while separate filers each get $2,640.

Sources

Primary sources opened and checked on November 2, 2026. Figures are for tax year 2026 unless a source says otherwise.

• Edvest 529 tax benefits: Wisconsin State Tax Deduction
• Edvest 529 home page footnote: 2026 deduction limits