OBBBA Homeowner Tax Deductions in 2026: What CPAs Need to Advise
The One Big Beautiful Bill Act (OBBBA) changed homeowner-related tax deductions in ways that will reshape the itemize-vs-standard-deduction calculus for millions of clients. The biggest shift: the SALT cap rose from $10,000 to $40,000, making property tax deductions meaningful again for clients in California, New York, New Jersey, and other high-tax states. At the same time, OBBBA made the TCJA mortgage interest limits permanent ($750,000 acquisition debt cap), and for clients in the 37% bracket, the new 2/37 rule reduces the effective value of all itemized deductions — including mortgage interest and property taxes — to roughly 35 cents on the dollar. The net result is a bifurcated planning environment: middle-income homeowners benefit from the SALT cap increase and may now itemize where they previously took the standard deduction, while high-income homeowners face a stealth reduction in itemized deduction value that requires active planning to navigate. CPAs need to model both the standard deduction comparison and the 2/37 interaction before advising homeowner clients on 2026 filing strategy.
Verify all provisions against the enacted text of OBBBA and await IRS guidance implementing these changes; exact 2026 thresholds will be confirmed in an IRS Revenue Procedure expected in late 2025 or early 2026.
The SALT Cap at $40,000: Biggest Homeowner Change
The most significant OBBBA change for homeowners is the state and local tax (SALT) deduction cap rising from $10,000 to $40,000, effective for tax years beginning after the Act's enactment. Under prior law (IRC §164(b)(6) as enacted by TCJA), taxpayers could deduct a maximum of $10,000 in combined state income taxes, sales taxes, and real property taxes — the same ceiling regardless of actual state tax burden. A homeowner paying $18,000 in property taxes and $20,000 in state income taxes received the same $10,000 deduction as someone in a no-income-tax state.
Under OBBBA, that cap rises to $40,000 — $20,000 for married filing separately. For clients in high-tax states with meaningful property tax burdens, this single change can unlock $10,000–$30,000 in additional deductible SALT that was previously wasted. A New York couple paying $22,000 in state income taxes and $14,000 in property taxes now has $36,000 of deductible SALT — up from $10,000 under prior law, assuming they meet the income threshold.
The $500,000 MAGI Phase-Out
OBBBA's $40,000 cap is subject to a phase-out for higher-income filers. The phase-out begins at $500,000 MAGI and fully reverts the cap to $10,000 at $530,000 MAGI — a 20-percentage-point cliff across just $30,000 of income. Clients whose MAGI sits between $500,000 and $530,000 face significant marginal rate distortions on income in that range because earning additional income reduces the SALT deduction dollar-for-dollar with income.
For planning purposes, clients with MAGI near $500,000 should model whether income-deferral strategies — maximizing retirement plan contributions, deferring year-end billings, accelerating business expenses — can preserve access to the higher SALT cap. Even a modest reduction in MAGI could be worth tens of thousands in additional SALT deductions. See SALT Cap at $40,000: How OBBBA Changes the State Tax Deduction for Your Clients for the full phase-out mechanics and modeling framework.
Mortgage Interest Deduction Under OBBBA
OBBBA made the TCJA mortgage interest deduction limits permanent, ending the uncertainty that would have otherwise reverted those limits after 2025. The result for 2026 and beyond:
Acquisition Debt Cap: $750,000
Mortgage interest on acquisition indebtedness (used to buy, build, or substantially improve a qualified residence) is deductible on up to $750,000 of debt ($375,000 for married filing separately). Interest on debt above that threshold is nondeductible personal interest. OBBBA retained the TCJA grandfather rule for loans originated on or before December 15, 2017 — those mortgages continue under the pre-TCJA $1,000,000 acquisition debt limit.
For clients who purchased homes in the last several years with conforming mortgages at or below the median price, the $750,000 cap generally does not bind. For clients in high-cost markets (New York, San Francisco, Los Angeles) with jumbo mortgages, the excess interest is permanently nondeductible unless the underlying debt was grandfathered.
Home Equity Loan Interest: Nondeductible Unless Acquisition-Linked
OBBBA retained the TCJA restriction eliminating the separate $100,000 home equity debt deduction. Interest on home equity loans or lines of credit is only deductible under the $750,000 acquisition debt umbrella if the proceeds were used to buy, build, or substantially improve the home — not for debt consolidation, college tuition, or other personal purposes. This is a point of frequent client confusion: homeowners often assume a home equity loan is deductible because it is secured by the home. Under current law, the use of proceeds determines deductibility, not the collateral.
Second Home Mortgage Interest
The $750,000 acquisition debt cap applies across the taxpayer's first and second residence combined. Clients with a primary mortgage and a vacation home mortgage must track combined acquisition indebtedness — if the aggregate exceeds $750,000, they must allocate deductible interest between the two properties on a principal-balance basis.
How the 2/37 Rule Reduces Mortgage Interest and Property Tax Benefits for High Earners
For homeowner clients in the 37% bracket (approximately $640,000 single / $768,000 MFJ in 2026), OBBBA's 2/37 rule materially reduces the effective value of itemized deductions — including mortgage interest and property taxes — even after the SALT cap increase.
The 2/37 rule requires taxpayers in the 37% bracket to reduce their total itemized deductions by 2/37 of the amount of income in the 37% bracket. The net effect is that each dollar of itemized deductions is worth approximately 35.1 cents in tax savings rather than the nominal 37 cents. See OBBBA 2/37 Rule: How the New Itemized Deduction Cap Affects High-Earning Clients for the full formula and illustrative calculations.
Practical impact for homeowners: A high-income client with a $900,000 mortgage (grandfathered at $1M) paying $45,000 in annual mortgage interest would expect a 37% deduction worth $16,650. After the 2/37 rule applies, the effective tax benefit may be closer to $15,800 — a difference that compounds across multiple itemized deductions. For clients with both mortgage interest and meaningful property taxes now deductible under the $40,000 SALT cap, the 2/37 rule erodes combined deduction value in proportion to their income in the 37% bracket.
Standard Deduction vs. Itemizing: The 2026 Math for Homeowners
OBBBA made the TCJA standard deduction structure permanent and it continues to be inflation-adjusted annually. For 2026, the standard deduction is approximately (IRS Rev Proc will confirm exact amounts):
| Filing Status | Approx. 2026 Standard Deduction |
|---|---|
| Single | ~$15,700 |
| Married Filing Jointly | ~$31,500 |
| Married Filing Separately | ~$15,750 |
| Head of Household | ~$23,600 |
Note: OBBBA also added an enhanced standard deduction for taxpayers aged 65 and older. Confirm the 2026 senior deduction amount from the enacted statute and IRS guidance.
Who should now itemize in 2026 (that didn't before)
The SALT cap increase to $40,000 changes the itemize threshold for clients who previously couldn't itemize because the $10,000 SALT cap left them with insufficient total itemized deductions. A married couple with:
- $22,000 in state income taxes
- $14,000 in property taxes = $36,000 SALT
- $24,000 in mortgage interest (on a $600,000 30-year mortgage at 7%)
- Combined itemized deductions: ~$60,000
Under prior law, this couple's itemized deductions were: $10,000 (capped SALT) + $24,000 (mortgage interest) = $34,000 — below the $30,000 standard deduction. Under OBBBA, itemized deductions become $36,000 (SALT) + $24,000 (mortgage interest) = $60,000 — nearly double the standard deduction. For this client, OBBBA turns a standard-deduction client into a clear itemizer.
Who still takes the standard deduction
Homeowners whose MAGI exceeds $500,000 face the SALT phase-out; at $530,000+ MAGI, the cap reverts to $10,000. Combined with the 2/37 rule eroding itemized deduction value for those in the 37% bracket, high-income homeowners may find that the break-even between standard and itemized is closer than expected. CPAs should model both options before assuming high-income homeowners with mortgages automatically benefit from itemizing.
For the full itemize-vs-standard decision framework, including bunching strategies and charitable deduction interaction, see Standard Deduction vs Itemized Deductions: How CPAs Decide for Clients in 2025.
Home Sale Exclusion: Unchanged by OBBBA
The §121 primary residence sale exclusion remains unchanged at $250,000 single / $500,000 married filing jointly. Homeowners who sell a primary residence after meeting the 2-of-5-year ownership and use tests can exclude that amount from gross income regardless of the sale price. OBBBA did not modify these amounts or the rules governing non-qualifying use, partial exclusions, or depreciation recapture on the home office portion. See How to Apply the Primary Residence Sale Exclusion (IRC §121): A CPA's Guide for full eligibility analysis.
Home Office Deductions: No OBBBA Changes
OBBBA made no changes to the home office deduction rules under IRC §280A. Self-employed clients with a qualifying home office can still deduct actual expenses (or use the simplified $5/sq ft method, capped at $1,500 per year) for the portion of their home used regularly and exclusively for business. The S-Corp accountable plan trap remains unchanged. Home office deductions remain a high-DIF audit flag and require documentation regardless of the OBBBA changes affecting other homeowner deductions.
Planning Strategies for Homeowner Clients in 2026
1. Re-run the standard vs. itemized comparison for every homeowner client
OBBBA's SALT cap increase invalidates prior-year itemize determinations for clients in high-tax states. Clients who have taken the standard deduction since 2018 because the SALT cap made itemizing noncompetitive may now benefit from itemizing. Run the comparison before advising on any deduction.
2. Model the MAGI phase-out cliff
For clients between $500,000 and $530,000 MAGI, quantify the dollar value of SALT deductions at risk and compare it to the cost of income-deferral strategies. Maximizing 401(k)/defined benefit contributions, electing installment sale treatment on a business asset, or timing year-end income can preserve access to the $40,000 SALT cap.
3. Address the home equity interest trap proactively
Review clients who have home equity lines of credit and are deducting the interest. Confirm whether the HELOC proceeds were used for acquisition or improvement of the home. Interest on HELOCs used for personal purposes has been nondeductible since 2018 and OBBBA does not change that. Clients who took out HELOCs for non-acquisition purposes and are still claiming the interest need corrections.
4. Apply the 2/37 rule before projecting high-income homeowner deduction benefits
For clients in the 37% bracket who own homes with large mortgages and property taxes, the 2/37 rule reduces effective deduction value. Factor this into tax projections and estimated payment calculations — the effective marginal rate on deductions is lower than the nominal bracket rate.
5. Coordinate SALT and charitable deduction strategies
For clients in high-tax states who now itemize because of the SALT increase, the charitable deduction interaction matters. OBBBA's 0.5% AGI floor on charitable deductions and the 35% benefit cap for 37% bracket filers affect total itemized deduction planning. A client who previously used a donor-advised fund to bunch charitable deductions may now have different optimal giving patterns. See OBBBA Charitable Giving Strategies for High-Income Clients in 2026 for the charitable/itemized interaction.
FAQ
Does the OBBBA $40,000 SALT cap apply to property taxes?
Yes. The SALT cap covers state income taxes, local income taxes, real property taxes, and (if elected instead of income tax) state sales taxes. All of these combined cannot exceed the $40,000 cap ($20,000 MFS), subject to the $500,000 MAGI phase-out. A homeowner paying $14,000 in property taxes and $22,000 in state income taxes has $36,000 of SALT — fully deductible under the new cap if MAGI is below $500,000.
Is mortgage interest on a $1,000,000 loan still deductible in 2026?
Only if the loan was originated on or before December 15, 2017. Grandfathered loans retain the pre-TCJA $1,000,000 acquisition debt limit. Loans originated after that date are subject to the $750,000 cap permanently under OBBBA. Interest on debt above the applicable limit is nondeductible personal interest.
Can my client deduct a home equity loan used for a kitchen renovation?
Yes — if the HELOC or home equity loan proceeds were used to buy, build, or substantially improve the taxpayer's first or second home, the interest is treated as acquisition indebtedness and is deductible subject to the $750,000 combined cap. Document the use of proceeds and keep records of the renovation costs; the deductibility turns entirely on purpose, not the loan vehicle.
How does the 2/37 rule affect a client with a large mortgage?
For clients in the 37% bracket, the 2/37 rule requires reducing total itemized deductions by 2/37 of the income subject to the 37% rate. This applies across all itemized deductions — mortgage interest, SALT, charitable contributions, and medical expenses are all reduced proportionately. The effective marginal tax benefit per dollar of itemized deductions falls from 37% to approximately 35.1%. For clients with large itemized totals, this can reduce after-tax deduction value by thousands of dollars annually.
Should my client stop paying state estimated taxes early because the SALT cap helps?
The $40,000 SALT cap is a deduction ceiling, not a payment strategy. Clients should continue paying actual state tax liability — there is no benefit to overpaying state taxes to maximize the SALT deduction beyond actual liability, and the $40,000 cap means the first $40,000 of SALT paid is deductible (subject to MAGI). Timing strategies generally don't help for SALT because state income taxes are deducted in the year paid, and property taxes are deducted in the tax year they are paid if they cover a period ending by year-end.
Did OBBBA raise the §121 home sale exclusion?
No. The primary residence sale exclusion remains $250,000 for single filers and $500,000 for married filing jointly. OBBBA did not modify these amounts, the ownership and use tests, or the rules governing partial exclusions and non-qualifying use periods.
Does the standard deduction increase for senior homeowners in 2026?
OBBBA increased the additional standard deduction for seniors aged 65 and older. Confirm the exact 2026 amount from the enacted statute and anticipated IRS guidance. Senior clients who own homes should model whether the enhanced standard deduction or itemizing (with the SALT cap benefit) produces the better result.
What documentation should homeowners keep for OBBBA-era deductions?
Property tax: county or municipal tax bills showing the amount and period covered. Mortgage interest: Form 1098 from the lender. For home equity interest claimed as acquisition debt: records of the purpose of the proceeds (contractor invoices, closing statements). SALT: state income tax returns, estimated tax payment confirmations, and Form 1098 for property taxes. Maintain these records for at least three years from the return due date, or seven years if there is any possible claim for loss.
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