Bank Gap by State
The Bank Gap in Wisconsin
Wisconsin's top tax rate of 7.65% on savings interest is meaningfully higher than most of its Midwest neighbors, even though the state's overall cost of living stays close to the national average.
Last reviewed August 7, 2026 · SwitchWize Research Desk
Before WI tax
$1,005/yr
on a $25,000 balance
After WI 7.65% tax
$928/yr
recoverable by switching
On a $25,000 balance, the gap is about $1,005 a year before tax. After Wisconsin's 7.65% top income-tax rate on the additional interest, you keep about $928. Because Treasury interest is exempt from Wisconsin income tax, routing that cash through a state-tax-exempt Treasury vehicle can recover most of the difference.
Estimated Bank Gap by balance
| Balance | Current earnings | Better-fit earnings | Estimated Bank Gap | After WI tax |
|---|---|---|---|---|
| $5,000 | $19 | $220 | $201 | $186 |
| $10,000 | $38 | $440 | $402 | $371 |
| $25,000 | $95 | $1,100 | $1,005 | $928 |
| $50,000 | $190 | $2,200 | $2,010 | $1,856 |
| $100,000 | $380 | $4,400 | $4,020 | $3,712 |
Estimates over 12 months at 0.38% current APY and 4.40% better-fit APY. The "After WI tax" column applies WI's 7.65% top income-tax rate to the additional interest; federal tax applies on top and is not shown. Example only — your result depends on your balance, rates, and time horizon.
Why Wisconsin changes the math
Wisconsin taxes interest income at a top rate of 7.65%. Treasury interest is generally exempt from that tax, so higher-income Wisconsin savers get a real after-tax lift from T-Bills or a government money market fund relative to a comparably priced taxable account.
Living costs across Wisconsin sit close to the national average, with Madison and the Milwaukee suburbs running somewhat higher, sizing typical emergency funds accordingly.
Cost of living in Wisconsin is near the national average, which shapes how large an emergency fund needs to be and therefore how many dollars the Bank Gap quietly costs on idle cash.
Because Wisconsin taxes savings interest but not Treasury interest, the highest after-tax yield is not always the highest headline APY. Run your tax profile through the short-term savings tool to see whether a Treasury bill or government money market fund beats a taxable account for you.
Open the short-term savings toolFrequently asked questions
Does Wisconsin tax high-yield savings account interest?
Is a high-yield savings account worth it in Wisconsin?
Are T-Bills better than a HYSA for Wisconsin savers?
Your personal Bank Gap
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Calculate my Bank GapEducational information, not tax or financial advice. State tax rules are summarized at a high level and depend on your full situation. Rates are illustrative of current market conditions and should be confirmed with the provider. Confirm tax treatment with a qualified professional.