TCJA Tax Sunset 2026: What It Means For Your Mortgage

The sweeping tax changes introduced by the Tax Cuts and Jobs Act (TCJA) of 2017 are scheduled to "sunset" at the end of 2025. For American homeowners and prospective buyers in 2026, this means a seismic shift in how mortgages, property taxes, and home equity are treated come tax season. The stakes are enormous: depending on your income, home value, and state of residence, your effective federal tax bill could increase or decrease by thousands of dollars annually.

What Is the TCJA Sunset? A Plain-Language Explainer

The Tax Cuts and Jobs Act was signed into law in December 2017 and represented the most comprehensive overhaul of the US tax code in three decades. To comply with Senate budget reconciliation rules, most of the individual tax provisions were written with a built-in expiration date: December 31, 2025. Unless Congress passes legislation to extend or replace them, these provisions automatically expire and the tax code reverts to its pre-2018 state beginning January 1, 2026.

As of May 2026, Congress has not yet passed a comprehensive extension—though negotiations are ongoing. This means millions of Americans are potentially facing their first full tax year under the reverted, pre-TCJA rules.

The Standard Deduction: The Biggest Change for Homeowners

The TCJA's most impactful change was nearly doubling the standard deduction. Here are the approximate figures as they stand and where they revert:

This single change triggers a cascade effect for homeowners. Under TCJA, the vast majority of homeowners—even those with sizable mortgages—found the standard deduction exceeded their potential itemized deductions, so they simply took the standard deduction. Post-sunset, with the standard deduction roughly halving, millions more homeowners will find that their combined mortgage interest + property taxes + state income taxes exceed the standard deduction threshold, making itemizing worthwhile again.

The Mortgage Interest Deduction (MID): Return to $1 Million Cap

Under TCJA, the mortgage interest deduction was limited to loans up to $750,000 in principal. Post-sunset, the cap reverts to $1,000,000. Here is what this means in practice:

• Loans under $750k: No change in deductible interest—you were already covered under both regimes.
• Loans between $750k and $1M (originated after 2017): Post-sunset, you can now deduct interest on the full balance, not just the first $750k. This could be worth $1,500–$3,000+ annually depending on your rate.
• Pre-2018 loans up to $1M: Were already grandfathered under TCJA. Post-sunset, the grandfather clause becomes moot and the $1M limit applies universally.
• Home equity loan interest: Post-sunset restores deductibility of up to $100,000 in home equity debt for any purpose (TCJA restricted this to home improvement use only).

The SALT Cap Expires: A Massive Win for CA, NY, NJ Homeowners

The $10,000 SALT (state and local tax) deduction cap was one of the most bitterly contested provisions of the TCJA. It disproportionately punished high-income homeowners in high-tax blue states—effectively a stealth tax increase on residents of California, New York, New Jersey, Illinois, Connecticut, and Massachusetts.

Post-sunset, the cap disappears entirely. Homeowners in these states can once again deduct their full property taxes plus state and local income taxes on Schedule A. The savings can be dramatic:

• A New York City homeowner paying $25,000 in property taxes + $30,000 in state/city income taxes was previously limited to deducting $10,000 total. Post-sunset, they could potentially deduct the full $55,000, saving roughly $13,200 annually at a 24% federal rate.
• A California homeowner with $18,000 in property taxes and $45,000 in state income taxes jumps from a $10,000 SALT deduction to a potential $63,000 deduction—a staggering change that dramatically improves the math of homeownership in high-cost California markets.

The AMT Trap: More Middle-Class Households Affected

One of the less-discussed consequences of the TCJA sunset is the reversion of Alternative Minimum Tax (AMT) exemption amounts. The TCJA dramatically increased AMT exemptions, effectively removing tens of millions of middle and upper-middle-class households from AMT exposure.

Post-sunset, the AMT exemption returns to lower pre-2018 levels (approximately $55,400 for singles and $86,200 for married filing jointly, versus the TCJA levels of ~$85,700 and ~$133,300 respectively). The AMT phase-out thresholds also drop sharply. This means:

• Households with incomes of $200,000–$500,000 who were removed from AMT under TCJA may find themselves subject to it again in 2026.
• The AMT disallows many common deductions—including the SALT deduction. So even homeowners who regain significant SALT deductions post-sunset may find the AMT limits their actual benefit.
• Stock option holders, homeowners in expensive markets, and high-income earners with large deductions should model their 2026 AMT exposure with a tax professional immediately.

Pass-Through Business Deduction and Child Tax Credit

Two other TCJA provisions expiring have indirect relevance to homeowners and families:

Section 199A Pass-Through Deduction (20% QBI Deduction): Self-employed individuals and owners of S-corps, LLCs, and partnerships have been deducting 20% of qualified business income under this provision. Post-sunset, this deduction disappears—effectively a significant tax increase on the self-employed. For real estate investors holding properties in pass-through entities (LLCs), this has direct cash flow implications.

Child Tax Credit: Reverts from $2,000 per child (TCJA) back to $1,000 per child, with lower phase-out thresholds. For families with two or three children, this alone represents $2,000–$3,000 in annual tax increases, directly reducing the discretionary income available for housing costs.

What to Do Now: A 2026 Action Plan for Homeowners

1. Model Your Itemized Deductions Under Both Scenarios

Use a tax planning tool or work with your accountant to calculate your 2026 federal tax under both regimes. Calculate your total mortgage interest, property taxes, state income taxes, charitable contributions, and other itemizable expenses. Compare this total to the post-sunset standard deduction. If you are materially above the standard deduction threshold, begin organizing and maximizing your itemized deductions now.

2. Consider Accelerating Deductions Into 2025

If the TCJA is NOT extended (still uncertain as of this writing), and you expect to be in a higher tax bracket in 2026 due to reverted rates, there may be strategies to accelerate income into 2025 (when TCJA rates still apply) or defer deductions to 2026 (when they may be more valuable). For example, if you are considering a large charitable donation, waiting until 2026—when itemizing becomes more beneficial—could maximize the deduction's tax impact.

3. Evaluate Roth Conversion Opportunities

The TCJA's lower tax brackets represent a closing window for Roth conversions. Converting traditional IRA or 401(k) balances to a Roth IRA while TCJA rates still apply (or were recently in effect) can lock in lower tax rates on those funds permanently. For homeowners with significant home equity who plan to downsize or sell, this strategy can be especially powerful for managing the tax impact of capital gains.

4. Refinancing Strategy

The sunset does not directly change the economics of refinancing—your break-even point is still driven by rate savings versus closing costs. However, if you have a mortgage above $750,000 originated after 2017, the post-sunset rules removing the $750k cap mean you will have more deductible interest going forward. Factor this into your total cost-of-ownership calculations when deciding whether to refinance, move, or stay put. Use the USFinNexus mortgage calculator below to model your exact scenario.

5. Watch Legislative Developments Closely

Congress may yet extend some or all TCJA provisions. The political dynamics are complex: extending all provisions would add an estimated $4+ trillion to the deficit over 10 years. As of May 2026, various compromise proposals circulate including permanent extension of lower brackets but allowing the SALT cap to lapse, or extending the standard deduction increase while retaining the $750k MID cap. Any of these outcomes would materially change the analysis above. Sign up for tax alerts and check back here for updates.

The Bottom Line

The TCJA sunset is one of the most consequential tax events for American homeowners in nearly a decade. The near-halving of the standard deduction alone will push millions of homeowners back into itemizing territory, where their mortgage interest, property taxes, and state income taxes suddenly become powerful tax weapons again. For homeowners in high-tax coastal states, the elimination of the SALT cap is potentially worth tens of thousands of dollars annually.

At the same time, the reversion of AMT exemptions, the loss of the pass-through deduction, and the reduction in the Child Tax Credit will create pain points for many households. The winners and losers from the TCJA sunset depend heavily on individual circumstances—income level, state of residence, mortgage size, and business ownership status.

The math for "Rent vs. Buy" fundamentally changes when you can deduct a massive property tax bill and interest on a $1M mortgage. If you are buying a home or refinancing in 2026, you need to factor these tax changes into your true cost of ownership. Consult with a tax professional, and use CFPB-compliant calculators to run your numbers under both the current and post-sunset scenarios.