In 2026, 16 US states use flat income tax (single rate for all earners), 25 states use progressive tax (rates increase with income), and 9 states have no income tax. The system that saves you money depends entirely on your income level and the specific state's rates.
The fundamental difference:
Key insight: Low-rate flat tax states (Arizona 2.5%, Indiana 2.95%, Pennsylvania 3.07%) beat high-bracket progressive states like California, New York and Oregon at $75,000 and above. High-rate flat tax states (Idaho 5.3%, Illinois 4.95%, Massachusetts 5%) lose to California's low bottom brackets for lower earners. The rate matters more than the system.
Sixteen states use flat income tax: Arizona (2.5%), Colorado (4.4%), Georgia (4.99%), Idaho (5.3%), Illinois (4.95%), Indiana (2.95%), Iowa (3.8%), Kentucky (3.5%), Louisiana (3%), Massachusetts (5% + 4% millionaire surtax), Michigan (4.25%), Mississippi (4%), North Carolina (3.99%), Ohio (2.75%, effective 2026 per House Bill 96), Pennsylvania (3.07%), and Utah (4.45%). Rates range from Arizona's 2.5% (lowest in the nation) to Idaho's 5.3% (highest flat tax).
Twenty-five states use progressive tax with graduated brackets: Alabama, Arkansas, California, Connecticut, Delaware, Hawaii, Kansas, Maine, Maryland, Minnesota, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Dakota, Oklahoma, Oregon, Rhode Island, South Carolina, Vermont, Virginia, West Virginia, Wisconsin, and DC. (Ohio and Louisiana switched to flat rates and moved to the flat-tax list — Ohio to 2.75% in 2026 per House Bill 96, Louisiana to 3% in 2025, and Iowa to 3.8% in 2025.) California has the highest top rate at 13.3%, followed by Hawaii (11%) and New York (10.9%).
It depends on your income and the specific rates. Low-rate flat tax states (Arizona 2.5%, Indiana 2.95%) beat high-bracket progressive states like California, New York and Oregon at $75,000 and above. High-rate flat tax states (Idaho 5.3%, Illinois 4.95%) lose to California's progressive brackets for low earners because California charges only 1-2% on the first $27,157 of taxable income while a flat tax charges its full rate on every dollar. At $50K income, California progressive (1.95% effective) saves $1,357/year vs Illinois flat 4.95% ($2,330). At $150K, Arizona flat 2.5% saves $6,213/year vs California progressive (6.37% effective).
Nine states have no income tax: Alaska, Florida, Nevada, New Hampshire (no tax on wages; interest/dividend tax repealed), South Dakota, Tennessee (ended Hall Tax in 2021), Texas, Washington, and Wyoming. These states charge 0% on wages, salaries, business income, and capital gains. They offset lost revenue with higher sales taxes (Texas 8.2%, Tennessee 9.55%) or property taxes (Texas 1.40% vs national 0.99% avg), or natural resource revenue (Alaska oil, Wyoming minerals).
Low earners (around $50K) usually pay less in progressive tax states with low bottom brackets than in high-rate flat tax states. California charges 1% on the first $11,456 and 2% on the next $15,701 (up to $27,157) of taxable income, resulting in $973 tax at $50K income (1.95% effective). Illinois's flat 4.95% rate results in $2,330 at $50K (4.66% effective). Low earners save $1,357/year in California. However, low-rate states like Arizona ($848 at $50K), Ohio ($606) and North Dakota ($0) beat California. The rate matters more than the system.
High earners ($150K+) pay significantly less in low-rate flat tax states. At $250K income: Arizona flat 2.5% = $5,848 vs California progressive = $18,861 (save $13,013/year). Even moderate flat tax states beat high progressive states—Colorado 4.4% = $10,292 vs California $18,861 (save $8,569). The exception: high-rate flat tax states like Idaho (5.3%, $12,135 at $250K) save less ($6,726 vs California) and still cost far more than low-bracket progressive North Dakota ($3,578).
Not all flat taxes are low. Idaho's 5.3% flat rate is higher than the top rate of some progressive states (North Dakota's is 2.5%). Idaho switched from a four-bracket progressive system (6% top rate in 2022) to a flat rate in 2023 (5.8%, cut to 5.3% by 2025), slightly lowering the top rate but eliminating lower brackets that protected low earners. High flat tax rates hurt low earners who would have paid 0-3% in the bottom brackets of a progressive system. Idaho only benefits high earners who would have hit the old 6% top bracket.
Arizona (2.5% flat) is the best flat tax state for high earners, offering the nation's lowest state income tax rate. At $250K income: Arizona charges $5,848 vs Indiana $7,346 (2.95%), Pennsylvania $7,675 (3.07%), or Colorado $10,292 (4.4%). For maximum savings, the 9 no-income-tax states (Florida, Texas, Nevada, Washington, Tennessee, Wyoming, South Dakota, Alaska, New Hampshire) beat Arizona by charging $0. But Arizona offers better weather/lifestyle than most no-tax states while still saving about $13,000/year vs California at $250K income.
Yes, states can switch systems through legislation or constitutional amendment. Recent changes: Louisiana switched from graduated brackets to a flat 3% for tax year 2025 (enacted in 2024), Mississippi phased to a flat 4% (above a $10,000 zero bracket) by 2026, North Carolina moved from progressive brackets to a flat rate in 2014 (now 3.99%). Some states have constitutional protections—Illinois requires a constitutional amendment (voter-approved) to switch from flat to progressive. Colorado's TABOR amendment requires voter approval for any tax increases. Switching from progressive to flat typically requires supermajority votes or constitutional amendments in most states.
Not always. Some flat tax states offset low income tax with high property or sales taxes. Illinois has 4.95% flat income tax and property tax tied for highest nationally (1.88%, tied with New Jersey)—total burden is among the heaviest in the country. Pennsylvania has 3.07% flat income tax but 1.26% property tax. Compare to Florida (0% income, 0.78% property, 7.01% sales) or Arizona (2.5% income, 0.51% property, 8% sales). At $120K income with a $300K home, Illinois total tax = $16,115 (13.4%) vs Florida $6,546 (5.5%). Always check total burden: income + property + sales taxes.
Massachusetts charges a 5% flat tax on all income, but voters approved a 4% surtax on income over $1 million (effective 2023; the threshold is indexed and is $1,107,750 for 2026). This makes Massachusetts technically flat for most people (below the threshold) but progressive at the top. At $900K income: about $44,680 (5% after the $4,400 exemption). At $1.5M income: about $90,100 total (about 6.0% effective). The surtax funds education and transportation. The marginal rate on income above the threshold is now 9% vs 5% before—higher than many progressive states.
Depends on your income and which specific states you're comparing. If earning $150K and comparing Arizona (2.5%) vs California (9.3% bracket), Arizona saves about $6,200/year in state income tax ($13,000 at $250K). If earning $50K and comparing Illinois (4.95%) vs California, California saves about $1,350/year. But no-income-tax states (Florida, Texas, Nevada, Tennessee) beat both systems for most earners. Calculate total tax burden (income + property + sales + cost of living) before deciding. A $10K tax savings means nothing if your rent doubles.
Effective rates, what the headline hides, 111+ countries. Every two weeks, free.
Bi-weekly. No spam. Unsubscribe in one click.
Last Updated: October 2026