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T-bills vs high-yield savings (after tax, by state)
Updated Oct 16, 2026 · By Jeison Cobb
The short answer
High-yield savings interest is taxed by your state. T-bill interest isn't. So a T-bill with a lower headline rate can still leave you with more money after tax.
Best HYSA: SoFi Checking & Savings at 4.20%. T-bill: US T-Bill 52 Weeks at 4.47% (state-tax free). Data as of 2026-10-16 12:30 ET, federal bracket 22%.
T-bill wins in 51 of 51 states. Even before state tax, the Treasury pays more, so it wins in every state.
| State | State tax | HYSA after-tax | T-bill after-tax |
|---|---|---|---|
| Alabama | 5% | 3.11% | 3.49% |
| Alaska | 0% | 3.28% | 3.49% |
| Arizona | 2.5% | 3.19% | 3.49% |
| Arkansas | 3.9% | 3.15% | 3.49% |
| California | 13.3% | 2.84% | 3.49% |
| Colorado | 4.4% | 3.13% | 3.49% |
| Connecticut | 6.99% | 3.05% | 3.49% |
| Delaware | 6.6% | 3.06% | 3.49% |
| District of Columbia | 10.75% | 2.92% | 3.49% |
| Florida | 0% | 3.28% | 3.49% |
| Georgia | 5.19% | 3.11% | 3.49% |
| Hawaii | 11% | 2.92% | 3.49% |
| Idaho | 5.3% | 3.10% | 3.49% |
| Illinois | 4.95% | 3.11% | 3.49% |
| Indiana | 2.95% | 3.18% | 3.49% |
| Iowa | 3.8% | 3.15% | 3.49% |
| Kansas | 5.58% | 3.09% | 3.49% |
| Kentucky | 3.5% | 3.16% | 3.49% |
| Louisiana | 3% | 3.18% | 3.49% |
| Maine | 7.15% | 3.04% | 3.49% |
| Maryland | 6.5% | 3.06% | 3.49% |
| Massachusetts | 9% | 2.98% | 3.49% |
| Michigan | 4.25% | 3.14% | 3.49% |
| Minnesota | 9.85% | 2.95% | 3.49% |
| Mississippi | 4% | 3.14% | 3.49% |
| Missouri | 4.7% | 3.12% | 3.49% |
| Montana | 5.65% | 3.09% | 3.49% |
| Nebraska | 4.55% | 3.13% | 3.49% |
| Nevada | 0% | 3.28% | 3.49% |
| New Hampshire | 0% | 3.28% | 3.49% |
| New Jersey | 10.75% | 2.92% | 3.49% |
| New Mexico | 5.9% | 3.08% | 3.49% |
| New York | 10.9% | 2.92% | 3.49% |
| North Carolina | 3.99% | 3.15% | 3.49% |
| North Dakota | 2.5% | 3.19% | 3.49% |
| Ohio | 2.75% | 3.19% | 3.49% |
| Oklahoma | 4.5% | 3.13% | 3.49% |
| Oregon | 9.9% | 2.95% | 3.49% |
| Pennsylvania | 3.07% | 3.18% | 3.49% |
| Rhode Island | 5.99% | 3.08% | 3.49% |
| South Carolina | 6.2% | 3.07% | 3.49% |
| South Dakota | 0% | 3.28% | 3.49% |
| Tennessee | 0% | 3.28% | 3.49% |
| Texas | 0% | 3.28% | 3.49% |
| Utah | 4.5% | 3.13% | 3.49% |
| Vermont | 8.75% | 2.99% | 3.49% |
| Virginia | 5.75% | 3.09% | 3.49% |
| Washington | 0% | 3.28% | 3.49% |
| West Virginia | 4.82% | 3.12% | 3.49% |
| Wisconsin | 7.65% | 3.03% | 3.49% |
| Wyoming | 0% | 3.28% | 3.49% |
FAQ
Are T-bills better than a high-yield savings account?
After tax, the best T-bill (US T-Bill 52 Weeks, 4.47%) beat the best HYSA (SoFi Checking & Savings, 4.20%) in 51 of 51 states as of 2026-10-16, assuming a 22% federal bracket. HYSAs win on convenience: instant access, no auctions.
Are T-bills taxed by states?
No. Interest on US Treasury bills is exempt from state and local income tax. It's still subject to federal income tax.
How is after-tax yield calculated?
HYSA: APY × (1 − federal) × (1 − state). T-bill: yield × (1 − federal).
Is a HYSA safer than T-bills?
Both are very safe: HYSAs are FDIC-insured up to $250,000 per depositor per bank, and T-bills are backed by the US government.
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