The $40,000 SALT Cap Explained (2025)

By Shakeel Muzaffar, reviewed by Prof. Dr. Khalil Mudassar, PhD · Last updated 2026-10-04

The SALT cap is the dollar limit on how much state and local tax you can deduct if you itemize. For tax year 2025 a new law raised it from $10,000 to $40,000 ($20,000 if married filing separately). The higher cap is temporary and phases down for high earners.

How the SALT Cap Changes Each Year, 2025 Through 2030

The SALT cap does not hold steady. The 2025 law set $40,000 for 2025, built in small yearly bumps through 2029, then lets the limit snap back to $10,000 in 2030. So the window of real relief is only five tax years.

The table below lists the cap for each year and flags how solid each figure is. The 2025 and 2026 amounts are fixed in law. The 2027 through 2029 amounts are projections from the statute’s 101% yearly step, since the IRS has not published official numbers for those years yet.

What Is the SALT Cap, and Who Does It Actually Help?

The SALT cap limits your deduction for state and local taxes, so it only matters if you itemize on Schedule A. If you take the standard deduction, the cap changes nothing for you, because you are not deducting these taxes line by line at all.

SALT stands for state and local taxes. On Schedule A you add up three things: either your state and local income tax or your general sales tax (you pick one, not both), plus your real estate (property) tax, plus any personal property tax. The total is then limited to the cap.

For many homeowners in higher-tax states, those pieces add up fast. A household with $22,000 of state income tax and $13,000 of property tax has $35,000 of SALT. Under the old $10,000 limit, $25,000 of that was lost. Under the 2025 cap of $40,000, the full $35,000 can be deducted, as long as the phase-down does not apply.

Want the deductible figure for your own numbers? The SALT Deduction Calculator applies the cap, the phase-down, and the floor for you. To see how the property-tax piece is figured in the first place, read our guide on how property tax is calculated.

How the High-Income Phase-Down Shrinks the SALT Cap

The $40,000 cap does not stay at $40,000 for everyone. Above a set income level, the cap shrinks. In 2025 it drops by 30 cents for every dollar of modified adjusted gross income (MAGI) above $500,000, or above $250,000 if married filing separately.

There is a hard stop. The reduction can never push the cap below a $10,000 floor ($5,000 MFS per the IRS worksheet). So even very high earners keep at least the old limit. For most filers, MAGI is simply the adjusted gross income on their return, raised only by certain foreign-income exclusions that most people do not have.

Here is the rule with real numbers, using a married-filing-jointly example for 2025. Say your MAGI is $560,000 and you paid $50,000 of SALT. Your income above $500,000 is $60,000. Thirty percent of that is $18,000, so your cap falls from $40,000 to $22,000. You deduct the smaller of $50,000 and $22,000, which is $22,000.

The cap reaches its $10,000 floor once the reduction hits $30,000. That happens when MAGI runs $100,000 past the threshold, meaning a 2025 joint filer with MAGI of $600,000 or more is capped at $10,000 regardless of how much SALT they paid.

The thresholds drift up too. The $500,000 start point becomes $505,000 in 2026, then grows by 1% a year through 2029, in step with the cap itself.

Why the Bigger SALT Cap Is Temporary

The short answer is that Congress wrote an expiration date into it. The 2025 law, Public Law 119-21, raised the cap only for tax years 2025 through 2029. For tax years beginning after December 31, 2029, the limit reverts to $10,000 ($5,000 MFS), the same figure set by the 2017 tax law.

That reversion is automatic. Unless a future Congress changes the rule, a filer who deducts $40,000 of SALT in 2029 may be back to a $10,000 ceiling in 2030. For anyone doing multi-year planning, the sunset is the single most important detail to keep in view.

This temporary design is why the yearly amounts matter. The relief is real but short, and it is largest for itemizers whose income sits below the phase-down threshold. Higher earners get a smaller cap, and the very highest keep only the $10,000 floor even during the five-year window.

SALT Cap vs. the Other 2025 Deduction Changes

The SALT cap is one of several itemized and above-the-line changes in the 2025 law, and they follow different rules. The SALT cap is a limit on an itemized deduction, and it phases down at high incomes. Other new breaks, like the senior deduction, work separately and have their own thresholds.

If you are weighing whether to itemize at all, the SALT cap is only part of the picture. A larger standard deduction or a separate senior break can tip the math the other way. Our Senior Deduction Calculator covers that provision, and the finance calculators hub lists the full set of 2025 tax tools.

SALT Cap: Frequently Asked Questions

Sources and Further Reading

Educational information, not tax advice; confirm with the current IRS guidance and a tax professional. The 2027 through 2029 figures are projections from the statute’s formula, not IRS-published amounts, and tax rules can change. Reviewed for accuracy by Prof. Dr. Khalil Mudassar, PhD. Last updated 2026-10-04.