Bank Gap by State

The Bank Gap in Kentucky

Kentucky's flat 4.0% income tax is written into state law with a path toward further reduction over time, applying evenly to savings interest regardless of income.

Big-bank average0.38%

Best available4.40%

$1,005/yrlost on a $25k balance · 4.02 pp spread

Last reviewed August 7, 2026 · SwitchWize Research Desk

Best savings APY

4.40%

high-yield

National average

0.38%

big-bank avg

APY gap

4.02 pp

spread

KY tax on interest

4.00%

top marginal rate

Before KY tax

$1,005/yr

on a $25,000 balance

After KY 4% tax

$965/yr

recoverable by switching

On a $25,000 balance, the gap is about $1,005 a year before tax. After Kentucky's 4% top income-tax rate on the additional interest, you keep about $965. Because Treasury interest is exempt from Kentucky income tax, routing that cash through a state-tax-exempt Treasury vehicle can recover most of the difference.

Estimated Bank Gap by balance

Estimated annual Bank Gap by balance at 0.38% current APY versus 4.40% better-fit APY, before and after KY state income tax
Balance	Current earnings	Better-fit earnings	Estimated Bank Gap	After KY tax
$5,000	$19	$220	$201	$193
$10,000	$38	$440	$402	$386
$25,000	$95	$1,100	$1,005	$965
$50,000	$190	$2,200	$2,010	$1,930
$100,000	$380	$4,400	$4,020	$3,859

Estimates over 12 months at 0.38% current APY and 4.40% better-fit APY. The "After KY tax" column applies KY's 4% 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 Kentucky changes the math

Kentucky taxes interest income at a flat 4.0% rate, with the legislature having already laid out conditions for further cuts in future years. Treasury interest is exempt from that tax, giving a modest but real after-tax edge to T-Bills over a comparably priced taxable HYSA.

A below-average cost of living keeps typical Kentucky emergency-fund balances modest, but the Bank Gap applies at full strength to whatever that balance is.

Cost of living in Kentucky is below 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.

After-tax tip

Because Kentucky 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 tool

Frequently asked questions

Does Kentucky tax high-yield savings account interest?

Yes. Kentucky treats savings interest as taxable income, with a top rate of 4%. Interest from U.S. Treasury bills and the Treasury portion of a government money market fund is generally exempt from Kentucky income tax, which can change the after-tax winner for higher earners.

Is a high-yield savings account worth it in Kentucky?

Yes. Even after Kentucky state tax, moving cash from a national-average account to a top high-yield savings account still leaves you with substantially more interest. The Bank Gap is far larger than the state-tax drag on the additional interest.

Are T-Bills better than a HYSA for Kentucky savers?

They can be for higher earners. Because Treasury interest is exempt from Kentucky income tax, a T-Bill or government money market fund can deliver a higher after-tax yield than a fully taxable savings account at a similar headline rate. The short-term savings calculator computes the breakeven for your exact tax situation.

Your personal Bank Gap

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Enter your balance and current rate. The Rate Gap Calculator shows the gap per year and over five years.

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Educational 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.