Millions of homeowners who itemize their federal tax returns can now deduct up to $40,000 in state and local taxes, quadrupling the $10,000 ceiling that had been locked in place since the 2017 tax overhaul. The higher cap applies to tax year 2025, meaning filers will first use it on returns due in 2026. Married taxpayers filing separately face a $20,000 limit. The change arrived through the One Big Beautiful Bill Act, signed into law as Public Law 119-21, and it sets up a slow-moving escalator of 1 percent annual increases through 2029, a pace that may not keep up with rising property taxes and incomes in high-cost states.
Why a $40,000 SALT cap changes the math for itemizers
The original $10,000 cap hit hardest in states with steep property and income taxes, forcing many middle- and upper-middle-income households to switch to the standard deduction and lose a benefit they had relied on for decades. The jump to $40,000 reopens meaningful savings for those filers. The IRS instructions for Schedule A for 2025 confirm the new ceiling and spell out that the deduction covers state and local income taxes (or sales taxes, at the taxpayer’s election) plus real estate taxes, all subject to the combined cap.
The relief, however, comes with built-in limits. The Congressional Budget Office projects the $40,000 figure will rise by just 1 percent a year through 2029, reaching roughly $41,600 by the end of that window. In states where property assessments and income-tax collections have been climbing at several times that rate, the gap between what taxpayers actually pay and what they can write off will widen each year. A household in a high-tax metro area whose combined state and local bill grows at 4 or 5 percent annually would see its effective deduction shrink in real terms well before the escalator expires.
The CBO outlook also flags a phasedown of the SALT limit for higher-income taxpayers starting in 2025. The IRS describes this as a modified adjusted gross income limitation with a floor, meaning filers above a certain income threshold will see their $40,000 cap reduced. Exact thresholds and reduction rates are set in the enacted statute, and the IRS guidance on deductible taxes confirms both the AGI-based phasedown and the combined nature of the cap. For many upper-income households, that means the headline $40,000 figure will function more as a starting point than a guaranteed benefit.
Homeowners weighing whether to itemize will still need to compare the SALT deduction, mortgage interest, and charitable gifts against the standard deduction. In lower-tax states, even a $40,000 cap may not be fully used, while in coastal metros with six-figure property tax bills, the higher ceiling may still fall short of actual outlays. The new rules also interact with long-standing limits on deducting certain personal charges, such as fees that are not treated as taxes, which remain nondeductible even if a homeowner has room left under the cap.
Legislative trail from $10,000 to $40,000
The increase traces directly to H.R. 1 of the 119th Congress, formally titled the One Big Beautiful Bill Act. The enrolled bill text on Congress.gov establishes the statutory language amending the Internal Revenue Code, and the Cornell Law Institute identifies the measure as Public Law 119-21, confirming it raised the SALT cap from $10,000 to $40,000. That fourfold increase is the first adjustment to the deduction ceiling since the Tax Cuts and Jobs Act imposed the original limit for tax years beginning after 2017, replacing what had previously been an essentially uncapped write-off for most individual filers.
Lawmakers from high-tax states had pushed for years to ease or repeal the cap, arguing that it penalized their residents and put downward pressure on school and infrastructure spending. Opponents countered that an unlimited SALT deduction disproportionately benefited higher-income households and effectively subsidized state and local tax hikes. The $40,000 compromise, paired with the gradual 1 percent escalator and the AGI-based phaseout, reflects an attempt to restore some relief for middle- and upper-middle-income homeowners without fully reopening the door for very large deductions at the top of the income scale.
Under the new statute, Treasury and the IRS are responsible for issuing regulations and updating forms so that taxpayers and preparers can apply the higher cap consistently. Those administrative steps include clarifying how the SALT limit interacts with existing rules on allocating real estate taxes between personal and rental use, as well as how to treat refunds of state income taxes that were previously deducted.
What homeowners should watch next
For property owners, the most immediate task is gathering accurate records of real estate tax bills and state income or sales taxes for 2025. The IRS notes in Publication 530 that only certain charges on a property tax bill qualify as deductible taxes, while amounts for services such as trash collection or local improvements generally do not. That distinction becomes more important as the nominal cap rises, because taxpayers may assume they can deduct everything on the bill when, in fact, only a portion counts toward the SALT limit.
Tax professionals expect the higher ceiling to push more homeowners back into itemizing, especially in suburbs and cities where property taxes alone can approach or exceed the old $10,000 cap. Still, the benefit will vary widely depending on income, location, and the pace of local tax increases relative to the law’s modest annual adjustments. With the new framework now locked in through 2029, households have a clearer, if imperfect, basis for planning around one of the most consequential line items on their federal returns.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
