State Income Tax vs. Federal Income Tax: An Overview
The U.S. has a multitiered income tax system under which taxes are imposed by federal, state, and sometimes local governments. Federal and state income taxes are similar in that they apply a percentage rate to taxable incomes.
However, they differ considerably regarding those rates and how they're applied, and by the type of income that is taxable and the deductions and tax credits allowed.
Key Takeaways
- The federal government and most states have income taxes.
- The rules and rates vary between individual states and the federal system.
- Federal taxes are progressive, with higher tax rates on higher income levels.
- Some states have a progressive tax system, while others impose a flat tax rate on all income.
- The Tax Cuts and Jobs Act, which took effect in 2018, made changes to the federal tax system, including an increase to the standard deduction.
State Income Tax
State income taxes can vary considerably from one state to another. Most states have either a flat or progressive income tax system. A flat tax system (also called a single-rate structure) applies a single tax rate to all income levels.
As of 2024, 12 states use the flat tax method: Arizona (2.5%), Colorado (4.4%), Georgia (5.49%), Idaho (5.8%), Illinois (4.95%), Indiana (3.05%), Kentucky (4.0%), Michigan (4.25%), Mississippi (4.7%), North Carolina (4.5%), Pennsylvania (3.07%), and Utah (4.65%). Washington has a flat tax that only applies to the capital gains income of high-earners, and Iowa is phasing in a flat tax by 2026.
In states that use progressive tax systems, greater income levels are taxed at a higher percentage rate. This is the same system used in the federal income tax system. Some states base their marginal tax brackets for this purpose on the federal tax code, but many states implement their own.
Some adjust their brackets annually to keep pace with inflation, as the federal government does, while others do not.
Hawaii has 12 tax brackets, while Kansas and six other states have only three. California's progressive tax system has the highest top tax rate of 13.3%, which applies to singles with taxable incomes over $1 million and married couples with incomes over $1,396,542. North Dakota has the lowest top marginal tax rate, with a 2.5% rate that applies to singles with incomes over $225,975 and married couples with incomes over $275,100.
Some states have little to no income tax: Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming don't tax residents on their income.
New Hampshire taxes only income from interest and dividends and not earned income from salary and wages. The state is phasing this out gradually and plans to repeal this fully by January 2025. Tennessee used to tax interest income and dividends, but it completed a phase-out on Jan. 1, 2021.
Income taxes are a significant source of revenue for individual states and the federal government, accounting for 50% of federal revenue in 2024.
Federal Income Tax
The U.S. Internal Revenue Code (IRC), which spells out the federal income tax rules, underwent significant changes, effective in 2018, with the passage of the Tax Cuts and Jobs Act (TCJA). The act enacted seven marginal tax brackets at the federal level: 10%, 12%, 22%, 24%, 32%, 35%, and 37%.
For the 2023 tax year, the top rate of 37% kicked in at $578,126 for singles and $693,751 for married couples filing jointly. For tax year 2024, the 37% rate kicks in at $609,351 for single filers and $731,201 for married couples filing jointly.
Here's a breakdown of the tax brackets and rates for 2023:
2023 Federal Tax Brackets and Rates | |||
---|---|---|---|
2023 Tax Rate | Single | Married Filing Jointly | Heads of Household |
10% | $0 to $11,000 | $0 to $22,000 | $0 to $15,700 |
12% | $11,001 to $44,725 | $22,001 to $89,450 | $15,701 to $59,850 |
22% | $44,726 to $95,375 | $89,451 to $190,750 | $59,851 to $95,350 |
24% | $95,376 to $182,100 | $190,751 to $364,200 | $95,351 to $182,100 |
32% | $182,101 to $231,250 | $364,201 to $462,500 | $182,101 to $231,250 |
35% | $231,251 to $578,125 | $462,501 to $693,750 | $231,251 to $578,100 |
37% | $578,126 or more | $693,751 or more | $578,101 or more |
And here's what they are for 2024:
2024 Federal Tax Brackets and Rates | |||
---|---|---|---|
2024 Tax Rate | Single | Married Filing Jointly | Heads of Household |
10% | $0 to $11,600 | $0 to $23,200 | $0 to $16,550 |
12% | $11,601 to $47,150 | $23,201 to $94,300 | $16,551 to $63,100 |
22% | $47,151 to $100,525 | $94,301 to $201,050 | $63,101 to $100,500 |
24% | $100,526 to $191,950 | $201,051 to $383,900 | $100,501 to $191,150 |
32% | $191,951 to $243,725 | $383,901 to $487,450 | $191,151 to $243,700 |
35% | $243,726 to $609,350 | $487, 451 to $731,200 | $243,701 to $609,350 |
37% | $609,351 or more | $731,201 or more | $609,351 or more |
Federal Taxes: Standard Deduction vs. Itemized
Taxpayers can claim either a standard deduction or itemize their deductions under the federal tax system. Standard deductions increased considerably in 2018 due to the TCJA, making it advantageous for many taxpayers to take the standard deduction.
Deductions reduce the income amount for calculations to determine a taxpayer’s tax liability. Here's a look at the standard deductions for the 2023 and 2024 tax years:
Standard Deduction Amounts for 2023 and 2024 | ||
---|---|---|
Filing Status | 2023 Standard Deduction | 2024 Standard Deduction |
Single | $13,850 | $14,600 |
Married Filing Separately | $13,850 | $14,600 |
Heads of Household | $20,800 | $21,900 |
Married Filing Jointly | $27,700 | $29,200 |
Surviving Spouses | $27,700 | $29,200 |
As mentioned above, states and the federal government differ in terms of the types of income that are taxed and the deductions and tax credits that they allow. For instance, pension and Social Security income is taxable under federal rules, while some states exempt these sources of income from taxation.
Other income exemptions include earnings from U.S. Treasury securities, such as savings bonds. These sources of income are exempt from state tax but are subject to federal taxes.
State Income Tax vs. Federal Income Tax Example
Consider a single taxpayer who lives in New Hampshire and reports taxable earned income of $75,000 a year plus interest income of $3,000 on their federal tax return.
State Taxes
We'll start with the state income taxes. New Hampshire has a $2,400 tax exemption for the interest and dividends tax, so tax is due only on the remaining $600 ($3,000 − $2,400) of interest and dividends income.
This means the taxpayer would pay just $24 ($600 × 0.04) in state taxes because New Hampshire taxes interest and dividend income only, at the rate of 4%. The taxpayer's effective state tax rate on their total income of $78,000 (tax obligation, $24, divided by taxable income, $78,000) would be 0.031%.
If this same person lived in Utah, all of their taxable income—both earned and unearned—would be subject to that state's 4.65% flat tax rate. In that case, their state tax bill would be $3,627 ($78,000 × 0.0465).
Federal Taxes
In terms of federal taxes, under the progressive system, this taxpayer would pay $1,160 on the first $11,600 of their income (excluding interest) that falls into the 10% tax bracket. They would pay 12% on their income from $11,601 to $47,150 ($4,266), and 22% on the amount greater than $47,150 ($6,127) for a total federal tax bill of $11,553. Their effective federal tax rate would be 15.4%.
What Is the Difference Between Federal and State Income Taxes?
Federal income taxes are collected by the federal government, while state income taxes are collected by the individual state(s) where a taxpayer lives and earns income. (It can get complicated if you live in one state and work in another, which happened frequently during the pandemic years.)
There are seven federal tax brackets, ranging from 10% to 37%, depending on your income and filing status. At the state level, some states use a flat-rate tax, while others impose a progressive system or have no state income tax at all.
Do Federal Income Taxes Differ by State?
Federal income tax rates are based on your income and filing status—not on where you live. Therefore, the same federal tax rates apply to everyone, no matter which state is their residence. However, state taxes vary, so a taxpayer's total tax liability will differ depending on where they live and earn income.
Which States Have No State Income Tax?
Eight states—Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming—have no state income taxes. New Hampshire doesn't tax earned wages, but it does tax interest and dividend income. However, New Hampshire began phasing out these taxes at the end of 2023, and beginning on Jan. 1, 2025, personal income in the state will not be taxed.
The Bottom Line
Federal taxes are the same wherever you live in the U.S. But state taxes can differ significantly—both in amount and in the philosophy behind them.
Some states charge a flat tax and others use a progressive system that taxes high-income taxpayers more than others. So be sure to take state taxes into account when comparing the cost of living in various places if you have a choice of jobs or are considering relocating.
Note that income taxes are just one element of taxation—property taxes, sales tax, and other measures can come into play in the way states raise revenue.