How to Calculate SALT Deduction: A Step-by-Step Guide for Taxpayers

If you live in a high-tax state like California, New York, New Jersey, or Illinois, the SALT deduction is one of the most important lines on your federal tax return. It can mean thousands of dollars in savings, or a frustrating ceiling that limits what you can actually deduct.

The rules changed significantly with the Tax Cuts and Jobs Act of 2017 and again with recent legislation. Many taxpayers still do not fully understand what qualifies, how the cap works, or how to calculate their deduction correctly.

What Is the SALT Deduction?

SALT stands for State and Local Taxes. The SALT deduction allows federal taxpayers who itemize deductions to deduct certain state and local taxes paid during the tax year from their federal taxable income.

The concept behind it is straightforward. You already paid these taxes to your state or local government. Allowing a federal deduction for those payments prevents you from being taxed twice on the same income.

The SALT deduction has existed in some form since the federal income tax was established in 1913. For most of that history, it was uncapped. The Tax Cuts and Jobs Act of 2017 introduced the $10,000 cap that still affects millions of taxpayers today, though that cap has recently been increased under new legislation.

What Taxes Are Included in the SALT Deduction?

The SALT deduction covers three categories of taxes. You can deduct any combination of these, but the total is subject to the cap.

State and Local Income Taxes

If your state charges an income tax, the amount you paid or had withheld during the year is deductible. This includes state income taxes withheld from your paycheck and any additional payments you made when filing your state return.

For a resident of Los Angeles earning $180,000, the California state income tax paid can easily reach $12,000 to $15,000 per year before the cap applies. A high earner in Manhattan paying New York State and New York City income tax combined faces an even larger burden.

If you made a state estimated tax payment in January of the current year that covered the prior tax year, you deduct it in the year you paid it, not the year it covers. This timing matters for planning purposes.

Property Taxes on Real Estate You Own

Real property taxes paid on your primary residence, vacation home, or land are deductible under SALT. This covers state, county, and local property taxes assessed on real estate.

For homeowners in high-property-value markets, this adds up fast. A homeowner in Pasadena, California with a property assessed at $900,000 pays roughly $9,000 to $11,000 per year in property taxes. A homeowner in Westchester County, New York or Bergen County, New Jersey may pay $15,000 to $25,000 per year in property taxes alone.

Property taxes paid through an impound or escrow account by your mortgage servicer are still deductible. The servicer pays the tax on your behalf. You deduct it in the year the servicer made the payment to the taxing authority.

Personal property taxes on vehicles are also deductible if the tax is imposed annually and based on the value of the vehicle. California’s vehicle license fee used to qualify under this provision in prior years. Check with a CPA about current California treatment.

Sales Taxes as an Optional Alternative

Instead of deducting state and local income taxes, you can choose to deduct state and local sales taxes paid during the year. You cannot deduct both. It is one or the other.

This option primarily benefits residents of states with no income tax, such as Texas, Florida, Nevada, and Washington. If you live in one of these states, you have no state income tax to deduct. The sales tax option gives you something to work with.

You can calculate your actual sales taxes paid, which requires keeping receipts all year. Or you can use the IRS Optional Sales Tax Tables, which estimate your deduction based on your income, family size, and state. The IRS provides a free Sales Tax Deduction Calculator at irs.gov to make this easier.

If you made a major purchase during the year, such as a vehicle, boat, or home building materials, you can add the actual sales tax on that purchase to the table amount. This can meaningfully increase your deduction. For business owners, it’s equally important to perform an accurate year-end inventory count, as proper inventory records and purchase documentation help support tax reporting and maximize eligible deductions.

What Does Not Count Toward the SALT Deduction?

Not every tax payment qualifies. Several categories are specifically excluded from the SALT deduction.

• Federal income taxes paid. These are never deductible on a federal return.
• Social Security and Medicare taxes withheld from wages. Payroll taxes do not qualify.
• Property taxes on foreign real estate. The SALT deduction applies only to taxes paid to U.S. state and local governments.
• Taxes paid on business property claimed elsewhere on your return. If you deduct property taxes through Schedule C or Schedule E as a business expense, you cannot also claim them under SALT on Schedule A.
• Transfer taxes paid at real estate closing. These are treated as part of your cost basis in the property, not as a deductible tax.
• Homeowner association fees and assessments, even when described as taxes.
• Fees for specific services like garbage collection, utility hookups, or sewer fees are not deductible as taxes even if charged by a government entity.

What Is the SALT Deduction Cap and How Much Is It Now?

The Tax Cuts and Jobs Act of 2017 capped the SALT deduction at $10,000 per year for all filing statuses except married filing separately, which has a $5,000 cap. This limit applied starting with the 2018 tax year.

The TCJA cap was set to expire after the 2025 tax year along with many other TCJA provisions. Congress took action in 2025 to address this. The Big Beautiful Bill signed into law in 2025 increased the SALT cap substantially. For tax years 2025 through 2029, the SALT deduction cap was raised to $40,000 for most filing statuses. The cap then increases by 1 percent per year through 2033, after which it reverts to $10,000.

However, this increased cap phases out for very high earners. The phaseout begins at $500,000 of modified adjusted gross income. Once your MAGI exceeds $600,000, the cap returns to the original $10,000 level. This income-based phaseout is new and changes planning calculations for high earners significantly.

For most taxpayers earning under $500,000, the $40,000 cap is a significant improvement. A family in the San Fernando Valley paying $18,000 in property taxes and $16,000 in California state income tax previously could deduct only $10,000. Under the new rules, their full $34,000 in state and local taxes is deductible.

How to Calculate the SALT Deduction: Step by Step

The calculation itself is not complicated once you gather the right numbers. Here is how to work through it.

Step 1: Determine Which Income Tax to Include

Look at your W-2 forms. Box 17 shows state income tax withheld. If you had multiple employers or lived in multiple states during the year, add the state tax withheld from each W-2.

Add any state estimated tax payments you made during the calendar year. These are the quarterly payments made directly to your state’s revenue agency, such as the California Franchise Tax Board or the New York State Department of Taxation and Finance.

Include any balance due payment you made when you filed your prior year state return, as long as you made that payment during the current tax year. For example, if you paid $800 to the California FTB in April 2025 when filing your 2024 return, that $800 counts in your 2025 SALT calculation.

Do not include your state tax refund in this calculation. However, be aware that if you claimed a SALT deduction in the prior year and received a state refund, that refund may be taxable federally under the tax benefit rule. Your state will send you a 1099-G for the refund amount.

Step 2: Add Your Property Taxes Paid

Gather your property tax statements for all real property you own. If your taxes are paid through an escrow account, check your year-end mortgage statement. It shows the total property taxes paid on your behalf during the year.

If you paid property taxes directly, check your county treasurer records. Most California counties let you look up payment history online. In Los Angeles County, go to ttc.lacounty.gov. In Orange County, use ttc.ocgov.com. Print or save your payment confirmation as documentation.

If you own rental property, do not include those property taxes in your SALT calculation. Rental property taxes belong on Schedule E as a business deduction. Including them on Schedule A also would be double-counting.

Step 3: Choose Income Tax or Sales Tax, Not Both

At this point you have your state and local income tax total. Now decide whether to use that amount or substitute it with your sales tax amount.

For most residents of California, New York, New Jersey, Illinois, Massachusetts, and other high-income-tax states, the income tax amount will be larger than any reasonable sales tax estimate. Use income taxes.

For residents of Texas, Florida, Nevada, Washington, South Dakota, Wyoming, and Alaska where state income tax is zero, use the sales tax option. Run the IRS Sales Tax Deduction Calculator at irs.gov to get your estimated deduction based on your state, income, and family size. Add actual sales tax paid on large purchases on top of that table amount.

Step 4: Add the Income or Sales Tax Total to Your Property Tax Total

Your SALT deduction is the sum of your chosen income or sales tax amount plus your real property taxes. Add these two numbers together.

Example: A married couple in San Jose, California pays $14,000 in California state income taxes and $12,000 in Santa Clara County property taxes. Their total SALT before the cap is $26,000.

Under the pre-2025 rules, their deduction would have been capped at $10,000. Under the new $40,000 cap effective for tax years 2025 through 2029, their full $26,000 is deductible assuming their MAGI is under $500,000.

Step 5: Apply the Cap to Your Calculated Total

Compare your calculated SALT total to the applicable cap for your filing status and income level.

• For tax years 2025 through 2029: $40,000 cap for single filers and married filing jointly, with phaseout starting at $500,000 MAGI
• For married filing separately: $20,000 cap under the new rules, subject to the same phaseout
• For tax years 2018 through 2024: $10,000 cap, $5,000 for married filing separately

If your SALT total is below the cap, you deduct the full amount. If it exceeds the cap, your deduction is limited to the cap amount. Enter the lesser of your calculated total or the applicable cap on Schedule A, Line 5e.

Step 6: Compare Your Total Itemized Deductions to the Standard Deduction

The SALT deduction only benefits you if you itemize. For 2025, the standard deduction is $15,000 for single filers and $30,000 for married filing jointly, reflecting annual inflation adjustments.

Add your SALT deduction to your other itemized deductions: mortgage interest, charitable contributions, and any other qualifying deductions. If this total exceeds your standard deduction, itemizing saves you money. If the standard deduction is larger, take it instead.

With the $40,000 SALT cap now in place, many homeowners in high-tax states who previously could not benefit from itemizing now can. A homeowner in Marin County, California paying $20,000 in property taxes and $15,000 in state income taxes has $35,000 in SALT alone, well above the $30,000 married standard deduction even before adding mortgage interest.

SALT Deduction Example: A California Homeowner in 2025

Let us walk through a complete, realistic example.

Taxpayer profile: Married couple filing jointly in Glendale, California. Combined W-2 income of $280,000. They own a home assessed at $850,000. No business income. MAGI is $280,000, well under the $500,000 phaseout threshold.

Their state and local tax payments for 2025:

• California state income taxes withheld from W-2s: $18,400
• California estimated tax payment made in January 2025 for 2024: $1,200
• Los Angeles County property taxes paid through escrow: $10,200

Total SALT before cap: $29,800. Under the 2025 rules with a $40,000 cap and MAGI of $280,000, they deduct the full $29,800.

They add $29,800 in SALT to $21,000 in mortgage interest deduction and $4,500 in charitable contributions. Total itemized deductions: $55,300. The married standard deduction is $30,000. They itemize and save based on the difference.

Under the old $10,000 SALT cap, they would have had $10,000 plus $21,000 plus $4,500 equals $35,500 in itemized deductions, still above the standard deduction but significantly less beneficial. The higher cap gave them an extra $19,800 in deductible SALT, saving them roughly $4,400 in federal taxes at their effective rate.

When Does It Make Sense to Take the SALT Deduction vs. the Standard Deduction?

The answer depends entirely on your total itemized deductions versus the standard deduction amount for your filing status.

You benefit from itemizing when your qualifying expenses, including SALT, mortgage interest, charitable contributions, and other allowable deductions, exceed the standard deduction threshold.

For most renters, the standard deduction wins. Without property taxes or mortgage interest, the SALT deduction alone rarely pushes itemized deductions above the standard deduction threshold.

For homeowners with a mortgage in high-tax states, the combination of SALT and mortgage interest deduction almost always makes itemizing worthwhile. The higher SALT cap under the new legislation makes this even more likely for 2025 through 2029 filers.

Run both scenarios every year. Tax software does this automatically. If you prepare your own return manually, calculate your total itemized deductions before committing to either method. Claiming the wrong approach costs money.

How to Claim the SALT Deduction on Your Federal Tax Return

The SALT deduction is claimed on Schedule A of Form 1040. Schedule A is the Itemized Deductions form. You attach it to your federal return when you choose to itemize.

On Schedule A, the relevant lines are:

• Line 5a: State and local income taxes, or general sales taxes if you choose that option
• Line 5b: State and local real estate taxes
• Line 5c: State and local personal property taxes
• Line 5d: Total of lines 5a through 5c
• Line 5e: Your SALT deduction, capped at the applicable limit

The IRS instructions for Schedule A walk through each line in detail. The current year Schedule A is available at irs.gov. IRS Publication 17, Your Federal Income Tax, also provides a comprehensive explanation of each itemized deduction category.

Who Benefits Most from the SALT Deduction?

The SALT deduction primarily benefits taxpayers who:

• Live in high-income-tax states like California, New York, New Jersey, Massachusetts, Oregon, or Minnesota
• Own real estate in high-property-tax counties or states like Westchester County in New York, Marin County in California, or Essex County in New Jersey
• Itemize deductions because their total deductible expenses exceed the standard deduction
• Have MAGI below the $500,000 phaseout threshold under the new higher cap rules

Taxpayers in states with no income tax and who rent rather than own real estate benefit the least. The sales tax option may still provide some deduction, but it rarely approaches the SALT amounts common in high-tax states.

Under the old $10,000 cap, even residents of high-tax states often saw limited benefit because their actual SALT far exceeded the cap. The new $40,000 cap changes this meaningfully for the middle and upper-middle income range.

Income-Based Phaseout: How High Earners Are Affected by the New SALT Rules

The increased SALT cap introduced under the 2025 legislation includes a phaseout provision that reduces the cap for high-income taxpayers. This is new and changes planning considerations significantly.

The phaseout works as follows. For taxpayers with MAGI between $500,000 and $600,000, the $40,000 cap reduces proportionally. By the time MAGI reaches $600,000, the cap has returned to $10,000. The reduction is calculated on a sliding scale over that $100,000 income range.

For a taxpayer earning $550,000 in MAGI, they sit halfway through the phaseout range. Their effective SALT cap is approximately $25,000, halfway between $40,000 and $10,000.

This phaseout creates a marginal rate effect in the $500,000 to $600,000 MAGI range. Each additional dollar of income in that range reduces your SALT cap by $0.30. For taxpayers in this income range, timing income, accelerating deductions, or using state PTET workarounds becomes especially valuable.

State Workarounds for the SALT Cap: The Pass-Through Entity Tax Strategy

Following the 2017 SALT cap, many states created workarounds to help their residents recover some of the lost deduction. The most widely used is the Pass-Through Entity Tax, also called PTET.

California enacted its own PTET under AB 150, signed into law in 2021. It allows partnerships, S corporations, and LLCs taxed as partnerships or S corporations to pay California income tax at the entity level rather than passing the liability to individual owners.

Because the entity-level payment is a business expense, it is fully deductible on the federal business return without regard to the SALT cap. The individual owner then receives a credit against their California income tax for the entity-level tax paid.

The IRS has confirmed in Notice 2020-75 and subsequent guidance that entity-level state income tax payments by pass-through entities are fully deductible business expenses at the federal level. This remains true even after the SALT cap increase.

Business owners in California, particularly those owning S corporations, multi-member LLCs, or partnerships along the tech corridor from San Jose to San Francisco, should discuss the California PTET election with their CPA before each tax year. The election must be made by the due date of the entity’s return.

Did the SALT Deduction Cap Expire After 2025?

The original $10,000 SALT cap from the Tax Cuts and Jobs Act was set to expire after December 31, 2025. Without congressional action, the deduction would have reverted to being unlimited.

Congress acted before that expiration. The 2025 tax legislation replaced the expiring $10,000 cap with a new $40,000 cap applicable for tax years 2025 through 2029, with annual 1 percent increases through 2033. The cap then returns to $10,000 after 2033 unless further legislation is passed.

This means taxpayers now face a known cap structure through 2033. Planners can build multi-year strategies around these known parameters, which was not possible under the uncertainty of the expiring TCJA provisions.

How the SALT Deduction Interacts with Other Itemized Deductions

The SALT deduction does not stand alone. It is one piece of the total itemized deductions picture. Understanding how it fits with other deductions helps you make smarter decisions.

Mortgage Interest Deduction

The home mortgage interest deduction is the deduction most commonly paired with SALT. You can deduct interest on mortgage debt up to $750,000 in loan principal for homes purchased after December 15, 2017. For older mortgages, the limit is $1 million.

A homeowner with a $700,000 mortgage at 6.5 percent pays roughly $45,000 in interest in the first year. That $45,000 in mortgage interest combined with a $35,000 SALT deduction creates $80,000 in itemized deductions well above any standard deduction threshold.

Charitable Contribution Deduction

Cash donations to qualified charities are deductible as itemized deductions up to 60 percent of your adjusted gross income. Donations of appreciated stock or property are deductible up to 30 percent of AGI.

Taxpayers who already itemize due to SALT and mortgage interest often find that adding charitable contributions costs them very little in after-tax terms. If you are already itemizing, the marginal tax cost of a charitable gift is reduced by your federal and state tax rate.

Bunching Strategy: When to Concentrate Deductions in One Year

Some taxpayers alternate between itemizing one year and taking the standard deduction the next. This bunching strategy concentrates deductible expenses into one year to exceed the standard deduction threshold, then takes the standard deduction in the off year.

SALT is harder to bunch because it depends on actual taxes paid during the year. But charitable contributions can be bunched easily. A donor-advised fund lets you contribute multiple years of charitable giving in one year, take the full deduction in the contribution year, and distribute grants to charities over time. This pairs well with a SALT-driven itemizing strategy.

Planning Considerations During the Temporary SALT Cap Expansion

The new $40,000 SALT cap is temporary. It applies through 2029 with modest increases. After 2033, it reverts to $10,000. This known timeline creates planning opportunities that smart taxpayers should discuss with their advisors now.

Timing of State Tax Payments

You can control when you make state estimated tax payments to some extent. If you are under the SALT cap and close to year-end, prepaying your Q4 state estimated tax payment that is due in January can pull that deduction into the current year.

The IRS generally allows this if the tax payment covers a liability that already exists. You cannot prepay estimated state taxes for a future year and deduct them in the current year. The IRS blocked this type of prepayment in IRS Notice 2018-54 following the TCJA.

For California residents, paying the Q4 California estimated tax payment due January 15 in December of the prior year pulls the deduction one year earlier. With the $40,000 cap now in place, this may be more beneficial than in recent years when the $10,000 cap made such timing irrelevant for many.

Coordinating SALT With Your Broader Tax Plan

SALT planning does not happen in isolation. Your decision to itemize affects which other deductions you claim and how you structure charitable giving, retirement contributions, and business expenses.

Higher-income taxpayers facing the SALT phaseout at $500,000 to $600,000 MAGI should work with a CPA or financial planner to model whether income-reducing strategies such as maximizing retirement contributions, harvesting capital losses, or structuring business income through a PTET can keep MAGI below the phaseout threshold.

The California Society of CPAs maintains a directory of qualified tax professionals at calcpa.org. For legal questions about business structuring to optimize SALT treatment, the State Bar of California at calbar.ca.gov lists attorneys who specialize in tax law.

Can Married Couples Filing Separately Each Claim a $20,000 SALT Deduction?

Under the new rules, married filing separately taxpayers have a $20,000 SALT cap each, totaling $40,000 combined if both spouses itemize. However, there is a critical restriction. If one spouse itemizes, the other spouse must also itemize and cannot take the standard deduction.

The standard deduction for married filing separately is $15,000 in 2025. If both spouses itemize and each has $20,000 in SALT, their combined deductible SALT equals $40,000, the same as filing jointly. The separate filing rarely produces a better SALT outcome than filing jointly for this reason.

Married filing separately triggers other disadvantages as well. It eliminates the student loan interest deduction, reduces IRA contribution deductibility, and bars the American Opportunity Credit and Earned Income Tax Credit. Filing separately purely for SALT purposes is rarely a winning strategy.

History of the SALT Deduction and Why the Cap Was Introduced

The SALT deduction dates to the Revenue Act of 1913, which established the modern federal income tax. For over a century, taxpayers could deduct state and local taxes without limitation. This was seen as a way to prevent double taxation on the same income.

The Tax Cuts and Jobs Act of 2017 introduced the $10,000 cap as part of a broader restructuring of individual taxes. The stated rationale was to simplify the tax code and reduce deductions that disproportionately benefited high-income taxpayers in high-tax states. Critics argued it amounted to a federal penalty on states that chose to fund public services through higher taxes.

The political debate over the SALT cap became one of the most contentious tax policy fights in recent years. Congressional representatives from California, New York, New Jersey, and Illinois pushed repeatedly to raise or eliminate the cap. The 2025 increase to $40,000 represented a compromise, expanding relief for middle-income homeowners while maintaining a ceiling for the highest earners.

Is the SALT Deduction Worth Claiming If I Am Close to the Standard Deduction Threshold?

The SALT deduction has no standalone value. It only produces a tax benefit as part of your total itemized deductions package. If your total itemized deductions, including SALT, are less than your standard deduction, you claim the standard deduction and the SALT calculation becomes irrelevant.

However, if your itemized deductions are close to the standard deduction threshold, think carefully about whether other deductions can tip the balance. Mortgage interest, charitable contributions, and casualty losses from federally declared disasters all count toward your itemized total.

Even if the SALT deduction alone does not justify itemizing, it can push you over the threshold when combined with other deductions. Do the math before deciding. Tax software does this comparison automatically, but understanding the mechanics helps you plan throughout the year, not just at filing time.

Work With a Tax Professional to Maximize Your SALT Deduction

The SALT deduction is one of the few federal tax benefits that directly rewards taxpayers who live and own property in high-tax states. With the cap raised to $40,000 for 2025 through 2029, millions of homeowners in California, New York, New Jersey, and other high-tax states can now deduct substantially more than they could under the old rules.

Calculating the deduction correctly requires gathering the right documentation, choosing between income tax and sales tax correctly, tracking property tax payments across multiple properties, and understanding how the income-based phaseout applies to your situation.

For straightforward situations, the calculation is manageable with good tax software and attention to detail. For taxpayers with complex income, multiple properties, business ownership, or MAGI near the phaseout range, working with a qualified CPA or tax advisor is worth the cost. The savings from proper SALT optimization can easily exceed professional fees, sometimes by a wide margin.

IRS Publication 17 covers Schedule A deductions in full. IRS Publication 530 covers homeownership-related tax items, including property taxes. Both are available free at irs.gov and are updated annually to reflect current law. If you need help applying these rules to your specific situation, a CPA firm in Granada Hills can help you interpret the guidance correctly and ensure your tax return reflects the latest IRS requirements.