Updated July 28, 2026. Quick answer: Partly, and it depends on your age and how much of the cap your other retirement income already uses. Wisconsin offers a retirement-income exclusion that is limited — by age, by a dollar cap, or both — so a conversion can be sheltered up to a point and taxed above it.
Confidence note: the rule is well established; the answer for you depends on your age and your other retirement income in the conversion year.
Why a conversion is a different question from a withdrawal
Almost every state summary answers “how does Wisconsin tax retirement income?” That is a question about distributions. A Roth conversion is not a distribution in the ordinary sense — it is a voluntary election to recognise income now in exchange for tax-free growth later. Whether a state’s retirement exclusion reaches that election is a separate question, and it is the one that decides your bill.
This is the most consequential case for planning, because the answer is a number rather than a yes or no. A capped exclusion means a conversion is not simply taxed or not taxed — it is taxed above the line where your other retirement income has already consumed the cap.
Two practical consequences. Converting in a year with less other retirement income leaves more of the cap available. And if the exclusion is age-gated, converting before you reach the gate can be markedly more expensive than converting after it — which is a timing decision, not a tax rate.
What Wisconsin does with the converted amount
State income tax: graduated, four brackets 3.5% to 7.65% top rate (2025 Act 15 widened the 4.4% second bracket)
How Wisconsin treats IRA and plan income: Taxable, but from TY2025 (2025 Act 15, signed July 3, 2025): taxpayers age 67+ may exclude up to $24,000 each ($48,000 MFJ if both spouses qualify) of income from qualified retirement plans and IRAs – no income test (replaced the old $5,000 income-tested 65+ subtraction). Also exempt: pre-1964 WI state teacher/public retirement systems, and US uniformed-services pensions.
What to ask a preparer about Wisconsin
How much of my exclusion will other retirement income already consume in the year I convert, and does my age at conversion change it?
Converting around a move
Converting in the year you move into Wisconsin is the case that catches people. Residency at the moment of conversion is what generally determines which state gets to tax it, so a conversion executed a week before a move and one executed a week after can produce different bills.
Four separate taxes change when you move, not one: income tax on withdrawals, treatment of Social Security, estate tax, and inheritance tax. A state that looks good on conversions can be worse on the other three.
The state bill is the smaller half
Whatever Wisconsin does, the conversion is federal ordinary income first. The federal bracket you land in, and whether the conversion pushes you over an IRMAA threshold two years later, will usually move more money than the state line does. The state answer tells you whether to convert here; the federal answer tells you how much to convert at once.
Paying the tax from outside the account matters more than either. Using converted dollars to pay the bill shrinks the balance that was the entire point of converting.
Sources
Authority: Wis. Stat. § 71.05(6)(b) as amended by 2025 Act 15; WI DOR Wisconsin Tax Bulletin 230 (July 2025); WI DOR Publication 106 (Tax Information for Retirees).
Compiled from state statutes, session laws and revenue-department publications and adversarially verified in July 2026. Dataset confidence for Wisconsin: high.
This page states what the cited authority says. It is not tax advice, and a conversion large enough to matter is worth putting in front of a preparer who can see your whole return.