The One Big Beautiful Bill Act (OBBBA) shifts the landscape for federal income tax deductions for state and local taxes (SALT), albeit temporarily. If you have high SALT expenses, the changes could significantly reduce your federal income tax liability. But it requires careful planning to maximize the benefits — and avoid potential traps that could increase your effective tax rate.

A little background

Less than a decade ago, eligible SALT expenses were generally 100% deductible on federal income tax returns if an individual itemized deductions. This provided substantial tax savings to many taxpayers in locations with higher income or property tax rates (or higher home values).

Beginning in 2018, the Tax Cuts and Jobs Act (TCJA) put a $10,000 limit on the deduction ($5,000 for married couples filing separately). This SALT cap was scheduled to expire after 2025.

What's new?

Rather than letting the $10,000 cap expire or immediately making it permanent, Congress included a provision in the OBBBA that temporarily quadruples the limit. Beginning in 2025, taxpayers can deduct up to $40,000 ($20,000 for separate filers), with 1% increases each subsequent year. Then in 2030, the OBBBA reinstates the $10,000 cap.

While the higher limit is in place, it's reduced for taxpayers with incomes above a certain level. The allowable deduction drops by 30% of the amount by which modified adjusted gross income (MAGI) exceeds a threshold amount. For 2025, the threshold is $500,000; when MAGI reaches $600,000, the previous $10,000 cap applies. (These amounts are halved for separate filers.) The MAGI threshold will also increase 1% each year through 2029.

Deductible SALT expenses include property taxes (for homes, vehicles and boats) and either income tax or sales tax, but not both. If you live in a state without income taxes or opt for the sales tax route for another reason, you don't have to save all your receipts for the year and manually calculate your sales tax; you can use the IRS Sales Tax Deduction Calculator to determine the amount of sales tax you can claim. (It includes the ability to add actual sales tax paid on certain big-ticket items, such as a vehicle.) The increased SALT cap could lead to major tax savings compared with the $10,000 cap. For example, a single taxpayer in the 35% tax bracket with $40,000 in SALT expenses and MAGI below the threshold amount would save an additional $10,500 [35% × ($40,000 − $10,000)].

The calculation would be different if the taxpayer's MAGI exceeded the threshold. Let's say MAGI is $560,000, which is $60,000 over the 2025 threshold. The cap would be reduced by $18,000 (30% × $60,000), leaving a maximum SALT deduction of $22,000 ($40,000 − $18,000). Even reduced, that's more than twice what would be permitted under the $10,000 cap.

The itemization decision

The SALT deduction is available only to taxpayers who itemize their deductions. The TCJA nearly doubled the standard deduction. As a result of that change and the $10,000 SALT cap, the number of taxpayers who itemize dropped substantially. And, under the OBBBA, the standard deduction is even higher — for 2025, it's $15,750 for single and separate filers, $23,625 for heads of household filers, and $31,500 for joint filers.

But the higher SALT cap might make it worthwhile for some taxpayers who've been claiming the standard deduction post-TCJA to start itemizing again. Consider, for example, a taxpayer who pays high state income tax. If that amount combined with other itemized deductions (generally, certain medical and dental expenses, home mortgage interest, qualified casualty and theft losses, and charitable contributions) exceeds the applicable standard deduction, the taxpayer will save more tax by itemizing.

Beware the "SALT torpedo"

Taxpayers whose MAGI falls between $500,000 and $600,000 and who have large SALT expenses should be aware of what some are calling the "SALT torpedo." As your income climbs into this range, you don't just add income. You also lose part of the SALT deduction, increasing your taxable income further.

Let's say your MAGI is $600,000, you have $40,000 in SALT expenses and you have $35,000 in other itemized deductions. The $100,000 increase in income from $500,000 actually raises your taxable income by $130,000:

MAGI

$500,000

$600,000

SALT deduction

$40,000

$10,000

Other itemized deductions

$35,000

$35,000

Total itemized deductions

$75,000

$45,000

Taxable income

$425,000

$555,000

At a marginal tax rate of 35%, you'll pay $45,500 (35% × $130,000) in additional taxes, for an effective tax rate of 45.5%.

In this scenario, even with your SALT deduction reduced to $10,000, you'd benefit from itemizing. But if your $10,000 SALT deduction plus your other itemized deductions didn't exceed your standard deduction, the standard deduction would save you more tax.

Tax planning tips

Your MAGI plays a large role in the amount of your SALT deduction. If it's nearing the threshold that would reduce your deduction or already over it, you can take steps to stay out of the danger zone. For example, you could make or increase (up to applicable limits) pre-tax 401(k) plan and Health Savings Account contributions to reduce your MAGI. If you're self-employed, you may be able to set up or increase contributions to a retirement plan that allows you to make even larger contributions than you could as an employee, which also would reduce your MAGI.

Likewise, you want to avoid moves that increase your MAGI, like Roth IRA conversions, nonrequired traditional retirement plan distributions and asset sales that result in large capital gains. Bonuses, deferred compensation and equity compensation could push you over the MAGI threshold, too. Exchange-traded funds may be preferable to mutual funds because they don't make annual distributions.

At the same time, because the higher cap is temporary, you may want to try to maximize the SALT deduction every year it's available. If your SALT expenses are less than $40,000 and your MAGI is below the reduction threshold for 2025, for example, you might pre-pay your 2026 property tax bill this year. (This assumes the amount has been assessed — you can't pre-pay based only on your estimate.)

Uncertainty over PTETs

In response to the TCJA's $10,000 SALT cap, 36 states enacted pass-through entity tax (PTET) laws to help the owners of pass-through entities, who tend to pay greater amounts of state income tax. The laws vary but typically allow these businesses to pay state income tax at the entity level, where an unlimited amount can be deducted as a business expense, rather than at the owner level, where a deduction would be limited by the SALT cap.

The OBBBA preserves these PTET workarounds, and PTET elections may remain worthwhile for some pass-through entities. An election could reduce an owner's share of self-employment income or allow an owner to take the standard deduction.

Bear in mind, though, that some states' PTET laws are scheduled to expire after 2025, when the TCJA's $10,000 cap was set to expire absent congressional action. There's no guarantee these states will renew their PTETs in their current form, or at all.

SALT deduction and the AMT

It's worth noting that SALT expenses aren't deductible for purposes of the alternative minimum tax (AMT). A hefty SALT deduction could have the unintended effect of triggering the AMT, particularly after 2025.

Individual taxpayers are required to calculate their tax liability under both the regular federal income tax and the AMT and pay the higher amount. Your AMT liability generally is calculated by adding back about two dozen "preference and adjustment items" to your regular taxable income, including the SALT deduction.

The TCJA increased the AMT exemption amounts, as well as the income levels for the phaseout of the exemptions. For 2025, the exemption amount for singles and heads of households is $88,100; it begins to phase out when AMT income reaches $626,350. For joint filers for 2025, the exemption amount is $137,000 and begins to phase out at $1,252,700 of AMT income.

The OBBBA makes these higher exemptions permanent, but for joint filers it sets the phaseout threshold back to its lower 2018 level beginning in 2026 — $1 million, adjusted annually for inflation going forward. (It doesn't call for this change for other filers, which might be a drafting error. A technical correction could be released that would also return the phaseout thresholds to 2018 levels for other filers.)

The OBBBA also doubles the rate at which the exemptions phase out. These changes could make high-income taxpayers more vulnerable to the AMT, especially if they have large SALT deductions.

Navigating new ground

The OBBBA's changes to the SALT deduction cap, and other individual tax provisions, may require you to revise your tax planning. We can help you chart the best course to minimize your tax liability.