Flat Tax States (2026)
15 U.S. states apply a single flat rate to individual income in tax year 2026, ranging from 2.5% in Arizona to 9% in Massachusetts.
"Flat" describes the rate schedule, not the bill. Every one of these states still allows a standard deduction, a personal exemption, or both — so the effective rate you actually pay is always below the headline rate, and it rises with income. The table shows both.
Flat rate states: income tax owed on $100,000, 2026
All 15 jurisdictions in this ranking
| # | Jurisdiction | Top rate | Tax on $100K | Effective rate |
|---|---|---|---|---|
| 1 | Arizona | 2.5% | $2,106 | 2.11% |
| 2 | Indiana | 2.95% | $2,921 | 2.92% |
| 3 | Louisiana | 3% | $2,614 | 2.61% |
| 4 | Pennsylvania | 3.07% | $3,070 | 3.07% |
| 5 | Kentucky | 3.5% | $3,382 | 3.38% |
| 6 | Iowa | 3.8% | $3,148 | 3.15% |
| 7 | North Carolina | 3.99% | $3,481 | 3.48% |
| 8 | Mississippi | 4% | $3,268 | 3.27% |
| 9 | Michigan | 4.25% | $3,999 | 4.00% |
| 10 | Colorado | 4.4% | $3,692 | 3.69% |
| 11 | Utah | 4.45% | $4,450 | 4.45% |
| 12 | Illinois | 4.95% | $4,805 | 4.81% |
| 13 | Georgia | 4.99% | $4,242 | 4.24% |
| 14 | Idaho | 5.3% | $4,447 | 4.45% |
| 15 | Massachusetts | 9% | $4,780 | 4.78% |
Tax on $100,000 assumes a single filer taking the standard deduction with no dependents, itemised deductions or credits. Local income taxes are flagged but not included. See methodology.
The headline rate is never the rate you pay
Take the table above. Every state in it applies one statutory rate, yet no two produce the same effective rate at $100,000, because the deduction each allows differs. A state with a higher flat rate and a large standard deduction can cost less than a state with a lower rate and none at all. That is why we publish the tax owed alongside the rate — marginal versus effective rate, explained.
Flat-tax states cutting rates for 2026
- Georgia
- · The flat rate fell from 5.19% to 4.99%, the standard deduction rose to $15,000 / $30,000 and the dependent deduction rose from $4,000 to $5,000, retroactive to taxable years beginning on or after January 1, 2026. (H.B. 463 (2026), the Georgia Economic Growth and Tax Relief Act of 2026)
- Indiana
- · Indiana's flat individual adjusted gross income tax rate fell from 3.00% to 2.95%; six counties raised their county income tax rates.
- Kentucky
- · Kentucky's flat individual income tax rate fell from 4% to 3.5% for taxable years beginning on or after January 1, 2026. (H.B. 1 (2025 Regular Session), 2025 Ky. Acts ch. 1)
- Mississippi
- · Mississippi's rate on taxable income above $10,000 fell from 4.4% to 4.0% for 2026, the next step in the statutory phase-down. (H.B. 531 (2022) schedule, continued by H.B. 1 (2025))
- North Carolina
- · The flat individual income tax rate fell from 4.25% to 3.99%. (S.L. 2023-134)
- · Additional rate reductions may apply for tax years beginning in 2027 if the General Fund revenue triggers in Session Law 2023-134 are met. (S.L. 2023-134)
- Utah
- · S.B. 60 (2026) cut the flat individual income tax rate from 4.5% to 4.45%, with retrospective operation to January 1, 2026. (S.B. 60 (2026))
Flat versus graduated
A flat state charges the same marginal rate on the first taxable dollar and the millionth. A graduated state charges more on higher slices. How the two structures differ, and who each favours · See the graduated states