The $40,400 SALT Cap Is a Five-Year Window — Here's Who Actually Benefits
The OBBBA raised the SALT deduction cap to $40,400 for 2026, but a 30% phase-down above $505,000 MAGI claws it back. Here's the real math on who benefits.
For 2026 the SALT deduction cap is $40,400 for single and married-filing-jointly filers ($20,200 if married filing separately), up from $40,000 in 2025. It rises 1% a year through 2029 and reverts to $10,000 in 2030.
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About the Author
Sujit KarkiFinance Researcher & Market Analyst
Independent finance researcher and market analyst with expertise in macroeconomics, equity markets, and personal finance. I help regular investors make better-informed decisions through rigorous, data-driven analysis.
The 2026 SALT cap is $40,400 (MFJ/single), up from $40,000 in 2025.
It phases down 30% of MAGI above $505,000, never below a $10,000 floor.
It's temporary — reverts to $10,000 in 2030 unless Congress extends it.
It only helps if your itemized deductions beat the standard deduction.
I've watched "SALT is back" headlines get people excited who will see exactly zero benefit from it, and I've watched people who could save real money not bother to itemize. Both mistakes come from reading the cap without reading the fine print. So let me walk through what the One Big Beautiful Bill Act actually did to the state-and-local-tax deduction, who it helps, and — just as important — who it quietly leaves at $10,000.
What actually changed
The Tax Cuts and Jobs Act capped the SALT deduction at $10,000 back in 2018. That cap made itemizing pointless for millions of people in high-tax states, because their property and state income taxes alone used to blow past that number. The OBBBA changed it: the cap is $40,000 for 2025 and $40,400 for 2026, then rises 1% a year through 2029 before snapping back to $10,000 in 2030. Married filing separately gets half — $20,200 in 2026.
Here's the first honest caveat: this is a deduction, not a credit. A $40,400 deduction is worth your marginal rate times that number, not $40,400 off your tax bill. In the 24% bracket, deducting an extra $30,000 of SALT you couldn't deduct before saves you about $7,200 — real money, but not the number in the headline.
The phase-down is the catch
This is the part the headlines skip. The raised cap is reduced by 30% of the amount your modified AGI exceeds $505,000 in 2026. It never drops below the old $10,000 floor ($5,000 if married filing separately, with the phase-down starting at $252,500 for that status).
Run the arithmetic. At $550,000 of MAGI you're $45,000 over the line; 30% of that is $13,500, so your cap falls from $40,400 to $26,900. Keep going: for every extra $1,000 of income you lose $300 of cap. By roughly $606,000 of MAGI you're all the way back to $10,000, right where TCJA left you. So the benefit is real for the merely-affluent and vanishes for the genuinely high-income — which is unusual, and worth planning around if your income is lumpy.
Warning
MAGI here adds back things like tax-exempt interest and deductible IRA contributions to your AGI. If you're near $505,000, a Roth conversion or a big capital gain can push you into the phase-down and cost you SALT cap on top of the extra tax.
Who actually benefits
Think about who has more than $10,000 but less than $40,400 of state and local taxes and an income under about $600,000. That's a homeowner in a high-tax state — New York, New Jersey, California, Illinois — with a solid but not stratospheric income. Property tax of $15,000 plus state income tax of $20,000 gets you to $35,000 of deductible SALT that used to be capped at $10,000. That's $25,000 of newly deductible expense.
Renters in low-tax states usually see nothing, because their SALT doesn't clear the standard deduction. That's not a loophole; it's just how itemizing works. I'll name the counterargument honestly: yes, a high-earning renter in California with large state income tax could benefit. But for most renters, the standard deduction still wins, and this whole change is a non-event for them.
The AMT sitting right next to it
One trap that got worse alongside this: the Alternative Minimum Tax. SALT is not deductible for AMT purposes at all, and the 2026 AMT exemption phases out starting at $500,000 of AMTI for single filers and $1,000,000 for joint filers — almost exactly where the SALT phase-down begins for singles. A high earner can get squeezed from both directions — claim a big SALT deduction for regular tax, then have AMT take part of it back. If you carry large SALT, model regular tax and AMT side by side before you count on the deduction actually landing.
If you've read my piece on the SECURE 2.0 Roth catch-up rule that hit high earners, this is the same theme again: a headline number that applies cleanly to some incomes and gets clawed back at others. Worth checking both before you assume a "high earner" break applies to you.
Estimate your 2026 SALT deduction
Interactive · estimate your 2026 SALT deduction
How much of your SALT can you actually deduct?
Your total state & local taxes paid$35,000
Modified AGI$505,000
Of your $35,000 in SALT, you can deduct $35,000 in 2026 — your cap at this MAGI is $40,400.
Your effective SALT cap
$0
Amount you can deduct
$0
Estimate only — not tax advice. 2026 figures per OBBBA; verify against IRS instructions before filing.
SALT cap window — data table
Filing status
Married filing jointly
Base 2026 cap
$40,400
Phase-down starts at MAGI
$505,000
Floor
$10,000
Your effective cap
$40,400
Amount you can deduct
$35,000
The calculator above uses the exact phase-down formula: your cap starts at $40,400 (or $20,200 married filing separately), drops 30 cents for every dollar of MAGI above the threshold, and never falls below the floor.
Here's What I'd Actually Do
Add up your real SALT — property tax plus the larger of state income or sales tax. If it's under $10,000, this whole change is irrelevant to you; take the standard deduction and move on.
Compare itemizing to the standard deduction for 2026. The SALT increase only matters if your total itemized deductions — SALT plus mortgage interest plus charitable giving — beat the standard deduction for your filing status.
If your MAGI is near $505,000, manage the timing. Bunching a Roth conversion into a lower-income year, or deferring a bonus, can preserve thousands of dollars of SALT cap.
Run the AMT in parallel if your income is high. A tax pro or good software will show whether AMT eats the benefit before you count on it.
Remember the clock. This window closes after 2029. If you have discretion over when to pay deductible state taxes, the generous years are now, not 2030.
This isn't tax advice for your specific return — it's the framework I'd use before I sat down with the actual numbers.
Frequently Asked Questions
For 2026 the SALT deduction cap is $40,400 for single and married-filing-jointly filers ($20,200 if married filing separately), up from $40,000 in 2025. It rises 1% a year through 2029 and reverts to $10,000 in 2030.
This is educational content, not financial or tax advice. I'm a researcher, not your advisor, and I don't know your specific tax situation. Rules and indexed thresholds change. Talk to a licensed tax professional before making decisions based on this. See the full disclaimer.
Sujit Karki|||5 min read