Bank Gap by State
The Bank Gap in New Jersey
The Bank Gap is a national phenomenon, but what to do about it in New Jersey is shaped by two state-specific forces: a high top income-tax rate and a cost of living well above the national average.
Last reviewed June 23, 2026 · SwitchWize Research Desk
| Balance | Current earnings | Better-fit earnings | Estimated Bank Gap | After NJ tax |
|---|---|---|---|---|
| $5,000 | $19 | $220 | $201 | $179 |
| $10,000 | $38 | $440 | $402 | $359 |
| $25,000 | $95 | $1,100 | $1,005 | $897 |
| $50,000 | $190 | $2,200 | $2,010 | $1,794 |
| $100,000 | $380 | $4,400 | $4,020 | $3,588 |
Estimates over 12 months at 0.38% current APY and 4.40% better-fit APY. The "After NJ tax" column applies NJ's 10.75% 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.
On a $25,000 balance, the gap is about $1,005 a year before tax. After New Jersey's 10.75% top income-tax rate on the additional interest, you keep about $897. Because Treasury interest is exempt from New Jersey income tax, routing that cash through a state-tax-exempt Treasury vehicle can recover most of the difference.
Why New Jersey changes the math
New Jersey taxes savings interest as income at a top rate of 10.75%. Because high-yield savings interest is fully taxable at the state level while U.S. Treasury interest is generally exempt, higher earners in New Jersey can sometimes keep more after tax with Treasury bills or a government money market fund than with a fully taxable account at a similar headline rate.
Higher essential costs in New Jersey make a three-to-six-month emergency fund a larger dollar figure than the national average, so the Bank Gap on that balance is correspondingly larger.
Cost of living in New Jersey is well above 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 New Jersey 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 New Jersey tax high-yield savings account interest?
Is a high-yield savings account worth it in New Jersey?
Are T-Bills better than a HYSA for New Jersey savers?
Enter your balance and current rate. The Rate Gap Calculator shows exactly what the gap is costing you, per year and over five years.
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.