The SALT Cap That Actually Applies to Your Client
For seven years, the SALT deduction conversation was simple: your client could deduct up to $10,000 in state and local taxes, regardless of how much they actually paid. The cap was flat, applied to everyone, and left no room for planning.
The One Big Beautiful Bill Act changed that. Starting in 2025, the SALT deduction cap rises to $40,000, indexed annually for inflation (the indexed amount for 2026 is $40,400). This sounds like a win for clients in high-tax states. It is not that simple.
The new law introduced a MAGI-based phase-out that did not exist before. The phase-out begins at $500,000 of modified adjusted gross income (indexed to $505,000 for 2026) for all filing statuses except married filing separately. For every $100 of MAGI above the threshold, the cap is reduced by $30. That is a 30% reduction rate. The cap can never fall below $10,000, which serves as a hard floor.
Working the math: the $40,400 cap must lose $30,400 before hitting the $10,000 floor. At $30 per $100 of excess income, that takes $101,333 of MAGI above the threshold. So the phase-out ceiling, where the cap settles at $10,000, is approximately $606,333 for 2026.
A married couple in New Jersey earning $600,000 does not get a $40,400 SALT deduction. Their MAGI exceeds the $505,000 threshold by $95,000. The reduction: $95,000 x 0.30 = $28,500. Their actual SALT cap is $11,900. If they earn $650,000, the excess is $145,000 and the reduction is $43,500, dropping the cap to the $10,000 floor. At $606,333 or above, the cap is $10,000.
This is the number advisors need to calculate. The headline $40,400 cap is the starting point, not the answer.
Who Benefits and Who Does Not
The new SALT cap creates clear winners and losers compared to the old $10,000 cap.
Clear winners: Clients with MAGI below the phase-out threshold who pay more than $10,000 in state and local taxes. A married couple in California earning $350,000 who pays $28,000 in state income tax and $12,000 in property tax can now deduct up to $40,400 instead of $10,000. That is $30,400 in additional deductions, worth $7,296 at the 24% bracket.
Partial winners: Clients with MAGI in the phase-out range ($505,000 to approximately $606,333 for 2026). They get more than $10,000 but less than $40,400. The benefit depends on where they land in the phase-out. A single filer in New York earning $575,000 has excess MAGI of $70,000. The reduction: $70,000 x 0.30 = $21,000. Their cap is $19,400, nearly double the old limit but well below the headline.
No change (low income): Clients who were already below the $10,000 cap. Retirees in low-tax states, clients with minimal property taxes, and anyone taking the standard deduction. The higher cap does nothing for them.
No change (high income): Clients whose MAGI fully phases out the increase. A married couple earning $800,000 in Connecticut who paid $65,000 in state and local taxes expected relief. Their MAGI is well above the $606,333 ceiling, so the phase-out reduces their cap to the $10,000 floor. That is exactly the same cap they had under prior law. The OBBBA gives them nothing new, but it does not make them worse off either. The $10,000 floor ensures that fully phased-out taxpayers are no worse than they were under the TCJA flat cap.
The Itemization Threshold Shift
The SALT cap change does not exist in isolation. It interacts with the standard deduction, which the OBBBA also made permanent at its higher level.
For 2026, the standard deduction is $16,100 for single filers and $32,200 for married filing jointly. A client only benefits from itemizing if their total itemized deductions exceed these amounts.
Under the old $10,000 SALT cap, many clients who previously itemized switched to the standard deduction because the cap eliminated their largest single deduction. A married couple with $30,000 in SALT, $15,000 in mortgage interest, and $5,000 in charitable contributions had $50,000 in itemized deductions before the TCJA. After the $10,000 cap, their itemized total dropped to $30,000. They still cleared the $32,200 standard deduction in some cases, but many clients with smaller mortgage balances or less charitable giving found themselves below the threshold and stopped itemizing.
The $40,400 SALT cap changes this calculation dramatically. That same couple now has $40,400 (SALT, assuming full cap) + $15,000 (mortgage) + $5,000 (charitable) = $60,400 in itemized deductions, nearly double the $32,200 standard deduction. For clients below the phase-out threshold, itemizing is a clear win.
This means the SALT cap increase will push some clients back into itemizing who have not itemized in years. Advisors need to revisit the itemization calculation for every client in a high-tax state.
Planning Strategies
MAGI management. Since the phase-out is MAGI-based, strategies that reduce MAGI can increase the effective SALT cap. Roth conversions add to MAGI (so time them carefully). Retirement plan contributions reduce MAGI. Timing of capital gains realizations, business income recognition, and deferred compensation payouts all affect where the client lands relative to the threshold. An advisor who coordinates income timing with the SALT phase-out can save thousands.
Property tax timing. State and local property taxes are deductible in the year paid. Some jurisdictions allow early payment of property taxes. If a client is in the phase-out range in 2026 but expects lower income in 2027, deferring a December property tax payment to January may increase the effective SALT cap in 2027 when their MAGI is lower. The reverse also works: if 2026 MAGI is below the threshold but 2027 will be high, prepaying the January property tax in December captures the deduction in the better year.
Charitable bunching returns. With more clients back to itemizing, charitable bunching (concentrating two or more years of charitable gifts into one year to exceed the standard deduction threshold, then taking the standard deduction in off years) becomes relevant again. A client who gives $10,000 annually might instead give $30,000 every three years to a donor-advised fund, itemizing in the bunching year and taking the standard deduction in the other two.
State income tax estimated payments. State income taxes paid (not just assessed) during the calendar year count toward SALT. Clients who make quarterly estimated payments can time the fourth quarter payment (normally due January 15 of the following year) by paying it in December to shift deductions between tax years. This strategy requires comparing the SALT cap and MAGI in both years.
The married filing separately trap. For married filing separately, the SALT cap is $20,200 (half the joint cap) and the phase-out threshold is $252,500 for 2026. The same 30% reduction rate applies. This can create situations where filing separately eliminates most of the SALT benefit. Run both calculations before deciding.
Entity structure for business owners. Pass-through entity (PTE) tax elections in many states allow S corporations and partnerships to pay state income tax at the entity level, bypassing the SALT cap entirely. The entity gets a state tax deduction, and owners receive a federal tax credit or deduction that is not subject to the SALT cap. More than 30 states now offer PTE elections. For business owners in phase-out territory, this may be the single most valuable planning strategy available.
The Sunset Problem
The OBBBA SALT provisions have a built-in expiration. The $40,400 cap (indexed) and the MAGI phase-out apply for tax years 2026 through 2029. After 2029, the SALT cap reverts to $10,000 unless Congress acts.
This four-year window creates a planning timeline. Strategies that depend on the higher SALT cap (like relocating deductions into high-SALT years) should be modeled with the 2029 sunset in mind. Clients considering moves from high-tax to low-tax states have a specific window in which the SALT benefit is available. After 2029, the calculus changes.
Advisors should be transparent about the uncertainty. “This deduction is available through 2029 under current law. We are building your plan around what the law says today, and we will adjust if it changes.” That framing manages expectations without speculating on legislative outcomes.
The Client Conversation
For clients in states with high income or property taxes, start with a simple comparison. “Last year, you could deduct $10,000 in state and local taxes. This year, depending on your income, you may be able to deduct up to $40,400. Let me calculate what your actual cap is.”
Then run the numbers. Show the MAGI, the phase-out calculation, and the resulting cap. Compare the total itemized deductions to the standard deduction. If itemizing now wins, show by how much.
For clients in the phase-out range, the conversation becomes about income timing. “If we can shift $50,000 of income from 2026 to 2027 (or vice versa), your SALT cap changes by $15,000 because of the 30% phase-out rate. At the 24% bracket, that is $3,600 in your pocket.” These are real planning opportunities that did not exist when the cap was a flat $10,000.
For business owners, raise the PTE election. “Your state allows your S corp to pay state income tax at the entity level. That payment bypasses the SALT cap entirely. For you, this could mean an additional $15,000 in deductible state taxes that would otherwise be capped.” If the client is working with a CPA, coordinate the election timing.
Key Takeaways
- Calculate each client’s actual SALT cap, not the headline number. The $40,400 cap is reduced by 30% of MAGI above $505,000 (2026 indexed threshold), with a $10,000 floor. Run the phase-out calculation for every client in a high-tax state.
- Revisit the itemization decision for every high-tax-state client. The higher SALT cap may push clients who switched to the standard deduction back into itemizing. Compare total itemized deductions to the $16,100/$32,200 standard deduction for 2026.
- Time income and deductions around the phase-out threshold. Small shifts in MAGI near $505,000 can change the SALT cap by thousands at the 30% reduction rate. Coordinate capital gains, retirement contributions, and estimated tax payments to optimize the effective cap.
- Evaluate pass-through entity tax elections for business owners. PTE elections bypass the SALT cap entirely. For S corp and partnership owners in phase-out territory, this may be worth more than any other single planning strategy.
- Plan within the 2029 sunset window. The OBBBA SALT provisions expire after 2029 unless extended. Build strategies that account for this timeline and revisit annually as the sunset approaches.
The Advisor’s Edge
The SALT deduction used to be the simplest line on Schedule A. You paid state and local taxes, you deducted them, no planning required. The $10,000 cap eliminated most of the planning. Now the OBBBA has created a graduated system with MAGI phase-outs, inflation indexing, entity-level workarounds, and a sunset date.
That complexity is where advisor value lives. A client reading a news article about the $40,400 SALT cap assumes that is their deduction. You calculate their actual cap after the phase-out. You model whether itemizing beats the standard deduction. You coordinate with their CPA on estimated payment timing and PTE elections. You plan across the four-year window.
The tax code rewards advisors who understand how provisions interact. SALT connects to MAGI, which connects to Roth conversion planning, which connects to Medicare premiums. The Certified Tax Specialist™ (CTS®) designation builds this kind of cross-cutting analytical skill. It is not about knowing one rule. It is about understanding how every rule affects every other rule in a client’s financial life.
For a closer look at entity-level tax strategies and exit planning for business owners, see Tax Strategies for Business Owners: QSBS, Opportunity Zones, and Exit Planning.
Sources and Notes: Content draws on CTS Module 1, Chapter 2 (Individual Income Taxation) and Module 2, Chapter 7 (Deduction Strategies). SALT cap provisions per One Big Beautiful Bill Act (P.L. 119-21), Section 110301. MAGI phase-out thresholds per Joint Committee on Taxation technical explanation (JCX-19-25). Standard deduction projections based on IRS inflation indexing methodology. PTE tax election availability tracked by the AICPA State Tax Policy Resource Center. The 2029 sunset provision per OBBBA Section 110301(c). This article is refreshed annually or as tax law changes.