State Income Tax Planning for Real Humans

By Tom, CPA · Updated October 27, 2026

Part of: Tax Planning

TL;DR: State income tax ranges from zero to over 10%. Your domicile can tax all your income; other states tax only income sourced there, with credits to avoid double tax. Residency audits focus on where you really live. The 2026 SALT cap is $40,400, and PTET elections can help business owners.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

The federal tax code is 4 million words long, and then there are fifty states, each with its own opinion. State income tax can range from zero to well over 10% of your income at the top, so for many households it is the second-biggest tax lever after federal. It is also the one people think about least until they move, retire or sell a business.

This guide covers how states tax you, residency and domicile, working across state lines, retirement income, the federal SALT deduction, pass-through entity taxes, and planning around a move. Specific state rates change often, so verify current rules with your state revenue department. As of Oct 2026.

CPA Warning Label: Moving to cut state tax right before a big sale draws residency audits. Document a genuine move, and confirm your state’s current rates and rules before acting.

How states tax income

States generally fall into three groups:

• No broad wage income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington and Wyoming. Some of these tax other things: Washington taxes certain long-term capital gains above a high threshold, and states without income tax tend to lean harder on sales and property taxes.
• Flat-rate states: one rate for all income levels. Several states have moved to flat taxes in recent years.
• Graduated-rate states: brackets like the federal system, with top rates that can exceed 10% in a few high-tax states.

Most states start from federal AGI or federal taxable income, then add and subtract items. Common differences: state treatment of Social Security benefits (most states exempt it), retirement income exclusions, municipal bond interest from other states (usually taxable), and whether the state follows recent federal changes. Some states decouple from federal provisions such as bonus depreciation.

A few cities and counties levy their own income taxes too, including New York City and many cities in Ohio, Pennsylvania and Michigan.

Residency and domicile

Your state of residence can tax all your income, wherever earned. A state where you are a nonresident can tax only income sourced there, such as wages for work performed there or rent from property there.

Two concepts matter:

• Domicile: your true, permanent home, the place you intend to return to. You have exactly one at a time. Changing it requires both moving and intending to stay.
• Statutory residency: many states treat you as a resident if you maintain a home there and spend more than a set number of days (often 183) in the state, even if domiciled elsewhere.

High-tax states audit people who claim to have left. Evidence that matters: where you spend your days, where your family lives, your driver's license, voter registration, vehicle registration, doctors, club memberships, where you keep valuables and pets, and which home you call home. Keep a day log and records. Keeping your old house and spending summers there is a classic way to lose a residency audit.

Working across state lines

• Nonresident returns. If you live in one state and work in another, you usually file a nonresident return in the work state and a resident return at home.
• Credit for taxes paid to other states. Your home state generally gives a credit for tax paid to the work state on the same income, so you do not pay twice in full. You still pay the higher of the two rates.
• Reciprocity agreements. Some neighboring states agree that workers pay only to their home state. File the exemption form with your employer.
• Convenience-of-the-employer rule. A few states, notably New York, tax remote workers for an in-state employer as if they worked in the state, unless the remote work is for the employer's necessity. This can create double tax without a full credit.
• Equity compensation is often allocated by workdays between grant and vest. See RSU tax planning.
• Rental property is taxed by the state where it sits. See rental property state taxes and what rental income is taxable.

Retirement income and early retirees

States vary widely in taxing retirement income. Most exempt Social Security. Many exclude some or all pension and IRA income, sometimes with age requirements or caps. A few states tax all of it.

Early retirees face a timing question: Roth conversions, IRA withdrawals and capital gains are taxed by your state of residence when realized. Converting in a no-tax state and then moving to a high-tax state is generally fine; the reverse can leave money on the table. Some states try to tax deferred compensation earned there, but federal law bars states from taxing most retirement plan distributions of nonresidents.

Watch for state taxes on capital gains at ordinary rates, which can make 0% federal gain harvesting less free than it looks. See IRMAA planning and estate planning basics, since about a dozen states also have estate or inheritance taxes.

The federal SALT deduction and PTET

State and local income taxes (or sales taxes, if you choose) plus property taxes are deductible on your federal return if you itemize, up to the SALT cap. For 2026, the cap is $40,400 ($20,200 married filing separately), reduced for modified AGI above $505,000 but not below $10,000, as of Oct 2026.

Pass-through entity taxes (PTET): most states with an income tax let partnerships and S corporations elect to pay state tax at the entity level. The entity deducts it as a business expense, outside the individual SALT cap, and owners get a state credit or exclusion. For business owners whose SALT exceeds the cap, PTET can save federal tax. The 2025 tax act preserved PTET for most businesses, though rules continue to develop; elections and deadlines vary by state.

For high earners, state tax drives net investment income tax and other calculations too. See NIIT on rental income.

Illustration: moving before a big sale

Illustration: a married couple plans to sell a business interest for a $2,000,000 long-term gain. They live in a state with a 9% effective rate on that gain and are considering a permanent move to a no-income-tax state.

Caveats: gain from selling a business with operations in the old state, or real estate located there, may remain taxable there regardless. Gain from intangible assets like stock is generally sourced to the seller's domicile. The old state will scrutinize a move made months before a sale. A genuine, documented move well ahead of the transaction is far more defensible. The federal tax does not change: at 20% plus 3.8% NIIT, about $476,000 either way.

Assumptions: illustrative rate; no installment sale; the move is real and permanent.

State planning checklist

• Know whether your state follows federal changes such as bonus depreciation and the new federal deductions for tips, overtime and seniors.
• Snowbirds: count days carefully. A few days over a statutory residency threshold can make you a full-year resident of a state you thought you were only visiting.
• Students and military members have special domicile rules; servicemembers generally keep their home state domicile regardless of where they are stationed.
• Check withholding when you move, and file part-year returns in the year of the move.
• Remote workers should confirm which state the employer withholds for.
• Consider PTET elections if you own a pass-through business.
• Before relocating for taxes, compare total cost: property tax, sales tax, insurance and housing. See growing income and career capital for the other side of the ledger.

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