State Income Taxes on Wages, Investments and Capital Gains Explained

State income taxes can apply differently depending on whether your money comes from wages, investments, or capital gains. Understanding these distinctions is important because every state establishes its own rules for taxable income, deductions, exemptions, and tax rates. State taxes can also interact with federal tax planning through the SALT Tax Deduction, which may allow taxpayers who itemize to deduct qualifying state and local taxes, subject to federal limits. Knowing how different types of income are treated can help taxpayers plan more accurately.

How State Income Taxes Work

State individual income taxes are separate from federal income taxes. In 2026, 42 states impose an individual income tax. Forty-one states tax wage and salary income, while Washington's individual income tax applies specifically to certain capital gains.Eight states Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, and Wyoming have no individual income tax.Among states taxing wages, some use a single rate, while others have graduated brackets in which marginal rates increase as taxable income rises.

How States Tax Wages and Salaries

For most employees, wages and salaries are the primary forms of taxable earned income. Employers generally withhold applicable state income tax from workers' paychecks and remit it to the appropriate state tax authority.The amount ultimately owed can depend on several factors, including:

• Gross and taxable income
• Filing status
• State tax brackets
• Deductions and exemptions
• Available state tax credits
• Residency and work location

State rates differ substantially. For example, Arizona has a 2.5% flat individual income tax rate in 2026. California uses graduated brackets with a top marginal individual income tax rate of 13.3%.A high marginal rate does not necessarily apply to every dollar a person earns. In a graduated system, different portions of taxable income are generally subject to different rates.

How Investment Income Is Taxed

Investment income can include interest, dividends, distributions, and other earnings generated by financial assets.Many states generally incorporate these forms of income into their individual income tax bases, although exclusions, deductions, and exemptions vary. This makes it important to check the rules in the taxpayer's state rather than assuming federal and state treatment will always be identical.New Hampshire provides a useful example of how state rules can change. Its tax on interest and dividend income was repealed beginning in 2025, leaving the state without an individual income tax.Investment income can therefore create very different state tax consequences depending on where the taxpayer is considered a resident.

How States Treat Capital Gains

A capital gain generally occurs when a capital asset is sold for more than its adjusted basis. Stocks, investment property, and other assets can potentially generate taxable gains when sold.At the state level, capital gains are often included in taxable income and subject to the state's individual income tax structure. However, there are important exceptions and special rules.Washington is particularly notable because it does not tax ordinary wage income but imposes an individual income tax on certain capital gains. For 2026, Washington's capital-gains structure has rates of 7% and 9%, with the higher marginal rate applying to qualifying capital gains above the relevant threshold.Missouri takes a different approach: its state individual income tax exempts capital gains income.Maryland also imposes an additional 2% surtax on capital-gains income for taxpayers with adjusted gross income exceeding $350,000.These differences demonstrate why investors should not assume that every state treats gains in the same way.

Short-Term and Long-Term Gains

At the federal level, the length of time an investment is held can affect the applicable capital-gains tax treatment. State rules may not mirror the federal distinction in the same way.Many states effectively tax taxable capital gains through their ordinary individual income tax systems, although state-specific exclusions, deductions, or special rates can alter the result.Investors should therefore consider both federal and state rules when evaluating the after-tax return from selling an asset.

How the SALT Tax Deduction Fits In

The SALT Tax Deduction can be relevant when state income taxes increase a taxpayer's overall tax burden. Taxpayers who itemize their federal deductions may generally include qualifying state and local income taxes or general sales taxes instead along with eligible property taxes, subject to federal requirements.For tax year 2026, the overall federal SALT deduction limit is $40,400, or $20,200 for married taxpayers filing separately. The limit begins decreasing at specified higher income levels but cannot fall below the statutory minimum.Taxpayers should compare itemized deductions with the federal standard deduction rather than assuming that paying state income tax automatically produces a federal tax benefit.

Residency Can Affect Where Income Is Taxed

Where you live and where you earn income can also influence state taxation. Someone who lives in one state and works in another may need both resident and nonresident tax returns.The rules can become more complicated for remote workers, investors who move during the year, and people receiving income from multiple states. Residency, domicile, and income-sourcing rules should therefore be reviewed carefully.

Conclusion

State income taxes on wages, investments, and capital gains vary considerably across the United States. Most states tax wages, many include investment and capital-gain income in their tax bases, and a few have distinctive rules for specific types of income.Understanding how your state treats each income source as well as deductions, tax brackets, residency requirements, and the SALT Tax Deduction can provide a clearer picture of your overall tax liability. Because tax laws and individual circumstances differ, taxpayers should confirm current requirements with the relevant state tax agency or a qualified tax professional.federal tax planning