Yes, you can deduct state income tax on your federal return, but two conditions have to line up. First, you must itemize on Schedule A rather than take the standard deduction. Second, your combined state and local taxes are capped: for the 2026 tax year, the SALT deduction ceiling is roughly $40,400 for most filers ($20,200 for married filing separately) under the One Big Beautiful Bill Act, up from the flat $10,000 that applied from 2018 through 2024. Filers with modified adjusted gross income above $500,000 face a phase-down toward a $10,000 floor, and the increase expires after 2029.
You Have to Itemize First
State income tax is only deductible if you itemize on Schedule A instead of claiming the standard deduction. Your combined itemized deductions — mortgage interest, state and local taxes, charitable gifts, and a few other categories — need to add up to more than your standard deduction for the year.1Internal Revenue Service. About Schedule A (Form 1040), Itemized Deductions
For 2026, the standard deduction is $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments from the One, Big, Beautiful Bill If your itemized expenses don’t clear that number, the standard deduction wins and your state income tax payments produce no federal benefit.
A married couple paying $12,000 in state income tax, $8,000 in property tax, $14,000 in mortgage interest, and $4,000 in charitable gifts has $38,000 in potential itemized deductions. That clears the $32,200 standard deduction, so itemizing pays. A single filer paying $6,000 in state income tax and $2,000 in charitable gifts has $8,000 in deductions and falls well short of $16,100. That filer gets nothing federal out of the state taxes paid. The comparison needs to happen every year, because a change in income, mortgage balance, or giving can flip the answer.
How Much State and Local Tax You Can Actually Deduct
Even when you itemize, there’s a ceiling. The Tax Cuts and Jobs Act capped the SALT deduction at $10,000 starting in 2018, and that limit held for seven years. The One Big Beautiful Bill Act, signed in 2025, raised it.3Internal Revenue Service. How to Update Withholding to Account for Tax Law Changes for 2025
For 2025 the cap became $40,000 ($20,000 for married filing separately), and it adjusts upward by roughly 1% each year. That puts the 2026 cap at approximately $40,400 ($20,200 for married filing separately).2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments from the One, Big, Beautiful Bill The yearly bumps continue through 2029, then the cap reverts to $10,000 in 2030.
The cap is an aggregate. It covers state and local income taxes (or sales taxes, if you elect that route), real property taxes, and personal property taxes combined. A homeowner paying $20,000 in property taxes and $25,000 in state income tax has $45,000 in SALT expenses but can deduct only $40,400. The remaining $4,600 disappears for federal purposes.
The Phase-Down Above $500,000
The higher cap isn’t available at every income level. If your modified adjusted gross income exceeds $500,000 ($250,000 for married filing separately), the cap begins shrinking by 30% of the excess.3Internal Revenue Service. How to Update Withholding to Account for Tax Law Changes for 2025
A single filer with $600,000 in MAGI exceeds the threshold by $100,000. Thirty percent of that is $30,000, which drops the cap from $40,400 to $10,400. By roughly $601,000 in MAGI, the cap bottoms out at $10,000, the same limit as the old law. So the raised cap is a middle- and upper-middle-income benefit. Filers well into six figures may see little or no improvement over the pre-2025 rules.
Income Tax or Sales Tax: You Pick One
Each year on Schedule A you choose between deducting state and local income taxes or state and local general sales taxes. You cannot claim both.4Internal Revenue Service. Topic No. 503, Deductible Taxes Either way, the amount counts toward the SALT cap.
The sales tax option matters most in states with no income tax, where the income tax deduction is zero. Even in states that do tax income, the sales tax route occasionally wins in a year with a large purchase such as a vehicle or boat. The IRS provides optional sales tax tables based on your income, family size, and state, and you can add actual sales tax paid on big-ticket items like motor vehicles, boats, and aircraft on top of the table figure.5Internal Revenue Service. Use the Sales Tax Deduction Calculator Compare that number against your state income tax withholding and estimated payments, and take whichever is larger.
State Tax on Business Income Is Not Capped
This is the piece most filers miss. The SALT cap applies only to state and local taxes claimed on Schedule A. State income taxes paid on business income — deducted on Schedule C for sole proprietors, Schedule E for rental income, or Schedule F for farming — are ordinary business expenses and don’t count toward the SALT cap at all.6Internal Revenue Service. Instructions for Schedule A (Form 1040) (2025)
If you have both a business and W-2 wages, only the state taxes attributable to your wage income go on Schedule A under the cap. State taxes tied to business profit flow through a separate part of the return. Self-employed filers who assume all their state taxes are capped often leave money on the table.
The Pass-Through Entity Tax Workaround
Owners of S-corporations and partnerships have another route around the cap. Most states now offer an elective Pass-Through Entity Tax, under which the business itself pays state income tax at the entity level. That payment is deductible by the entity as an ordinary business expense and reduces the taxable income that flows through to owners on Schedule K-1.7Internal Revenue Service. IRS Notice 2020-75
The IRS confirmed in Notice 2020-75 that entity-level state tax payments are not counted against any individual owner’s SALT cap. Owners then receive a corresponding state tax credit for the taxes the entity already paid, preventing double taxation at the state level.8Multistate Tax Commission. State Pass-Through Entity (PTE) Taxes
The election has to be made at the state level each year, and it applies only to partnerships and S-corporations. Sole proprietors and single-member LLCs taxed as disregarded entities generally don’t qualify, though a single-member LLC that elects S-corporation treatment may be eligible in some states. Rules vary, so check your state before electing.
Timing Your Payments
For most individuals, federal law lets you deduct state taxes in the year you actually pay them, not the year they’re assessed or the year they relate to.9eCFR. 26 CFR 1.461-1 – General Rule for Taxable Year of Deduction That creates room to plan. A fourth-quarter estimated state tax payment normally due January 15 can be paid in December instead and deducted on the current year’s return.
Two constraints. Property taxes have to be officially assessed under state or local law before year-end; prepaying a tax that hasn’t been levied doesn’t create a deduction. And moving a payment into the current year means it can’t be deducted next year, so the strategy only helps if your itemized deductions are higher now than they will be later. With the cap reverting to $10,000 after 2029, accelerating payments into the higher-cap years may be particularly worth doing.
Watch Out for the Alternative Minimum Tax
High-income filers who clear the SALT hurdles can still lose the deduction to the Alternative Minimum Tax. When calculating AMT liability, you must add back all state and local tax deductions: income taxes, property taxes, and sales taxes are all disallowed.10Office of the Law Revision Counsel. 26 USC 56 – Adjustments in Computing Alternative Minimum Taxable Income
For 2026, the AMT exemption is $90,100 for single filers and $140,200 for married couples filing jointly, with phase-outs starting at $500,000 and $1,000,000 respectively.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments from the One, Big, Beautiful Bill Filers with large SALT deductions, substantial income, and few other AMT preferences should run both calculations before counting on the deduction to lower the bill. State taxes deducted above the line as part of computing adjusted gross income — business taxes on Schedule C, E, or F — are not added back for AMT purposes.10Office of the Law Revision Counsel. 26 USC 56 – Adjustments in Computing Alternative Minimum Taxable Income
If You Get a State Refund Later
A refund of state income taxes may count as taxable income on next year’s federal return. Under the tax benefit rule, you include the recovery in income only to the extent the original deduction actually reduced your federal tax.11Internal Revenue Service. Section 111 – Recovery of Tax Benefit Items
Two situations make a refund fully tax-free. If you took the standard deduction the year you paid the state taxes, the refund isn’t taxable, because those payments never produced a federal benefit. If you itemized but only barely cleared the standard deduction, only the refund amount up to that excess is taxable.
Say your itemized deductions were $33,000 against a $32,200 standard deduction, an $800 advantage. If you later receive a $2,500 state refund, only $800 of it is taxable. The other $1,700 produced no federal benefit and doesn’t get reported as income. Your state will send Form 1099-G showing the total refund, but the form doesn’t compute the taxable portion.12Internal Revenue Service. About Form 1099-G, Certain Government Payments Most tax software handles the tax benefit calculation if you carry over prior-year data, but the number on the 1099-G and the amount you actually owe tax on aren’t the same thing.