TCJA Sunset 2026: What Every American Must Know About the Tax Cuts & Jobs Act Expiration

How Does the TCJA Sunset Affect the Estate Tax Exemption?

The TCJA temporarily doubled the federal estate and gift tax basic exclusion amount under 26 U.S. Code § 2010. Adjusted for inflation, this allowed individuals to shield approximately $13.99 million in 2025 ($27.98 million for married couples) from federal wealth transfer taxes, including the Generation-Skipping Transfer (GST) tax. When the TCJA expired on January 1, 2026, this exemption reverted to approximately $7 million per person (the pre-TCJA $5M base adjusted for inflation). (Note: Over a dozen states impose their own estate or inheritance taxes at thresholds far below the federal limit, sometimes triggering at just $1 million or $2 million.)

The one silver lining: the IRS issued final anti-clawback regulations in 2019, clarifying that gifts made during the TCJA years — when the exemption was higher — will NOT be clawed back and subjected to estate tax at death. This means large lifetime gifts already made before December 31, 2025, are fully protected. However, unused TCJA exemption cannot be retroactively accessed; that specific "use-it-or-lose-it" planning opportunity officially closed on January 1, 2026. Because the exemption is applied bottom-up, if an individual gifted $6 million before the sunset, that amount is subtracted from the new ~$7 million limit, leaving only ~$1 million in remaining lifetime exemption. Taxpayers do not get to keep the "top half" of the expired TCJA limit.

Will the Child Tax Credit and AMT Change in 2026?

Alternative Minimum Tax (AMT)

The Tax Cuts and Jobs Act (TCJA) dramatically increased Alternative Minimum Tax (AMT) exemptions and phase-out thresholds under 26 U.S. Code § 55, effectively eliminating this parallel tax burden for many upper-middle-income taxpayers. The AMT operates as a mandatory secondary tax system designed to prevent high earners from using excessive deductions to avoid paying a baseline tax rate. For tax year 2025, the AMT exemption was approximately $137,000 for single filers and $220,700 for married couples filing jointly (MFJ).

In 2026, AMT exemptions revert to pre-TCJA baseline levels adjusted for inflation—estimated at roughly $55,400 for single filers and $86,200 for married couples. Crucially, the phase-out thresholds also plummet, meaning taxpayers who haven't owed AMT since 2017 may suddenly face it. Key AMT preference items that trigger this tax include large Incentive Stock Option (ISO) exercises, significant state and local tax (SALT) deductions, and accelerated depreciation. Taxpayers expecting liquidity events or high SALT burdens in 2026 should consult a tax professional to model their potential AMT exposure.

Child Tax Credit

Under the TCJA, the Child Tax Credit (26 U.S. Code § 24) doubled from $1,000 to $2,000 per qualifying child under age 17, and the income phase-out threshold was raised to $400,000 for married couples. After the sunset, the credit reverts to $1,000 per qualifying child, and the phase-out threshold drops drastically back to $110,000 for MFJ ($75,000 for single filers). The refundable portion—known as the Additional Child Tax Credit, which allows lower-income families to receive a refund even if they owe no income tax—will also revert to its stricter pre-TCJA structure, lowering the maximum refundable amount and raising the earned income threshold required to qualify.

One major shift that may benefit certain taxpayers is the return of personal exemptions and miscellaneous itemized deductions. Post-sunset, taxpayers can once again claim personal exemptions—estimated at roughly $5,500 per person in 2026—for themselves and their dependents under 26 U.S. Code § 151. However, this benefit returns alongside a roughly 50% reduction in the standard deduction, meaning millions of Americans will once again need to itemize their taxes to minimize their liability.

Additionally, the sunset restores the deduction for miscellaneous itemized expenses that exceed 2% of Adjusted Gross Income (AGI). This allows W-2 employees and investors to deduct unreimbursed employee expenses, union dues, investment advisory fees, and tax preparation costs. To maximize this restored deduction, taxpayers should begin tracking these specific expenses meticulously starting in January 2026.

Note: This is general information, not legal or tax advice. Tax laws are subject to change, and individual circumstances vary; consult a qualified CPA or tax attorney for guidance specific to your situation.

Who Will Be Most Affected by the 2026 Tax Changes?

While the expiration of the Tax Cuts and Jobs Act (TCJA) impacts nearly all US taxpayers, certain groups will see a disproportionate increase in their tax liabilities. (Note: This is general information, not legal or tax advice. Tax laws vary by state; consult a qualified tax professional regarding your specific situation.)

• Pass-through business owners (LLCs, S-corps, sole proprietors): The scheduled expiration of the 20% Qualified Business Income (QBI) deduction under IRC Section 199A, combined with higher individual income tax rates, creates a substantial combined tax increase. Business income will once again be fully taxed at the owner's marginal individual rate.
• High-income individuals ($250K–$600K range): These taxpayers face the reinstatement of the 33% and top 39.6% marginal tax brackets (up from the TCJA's 37% top rate). Additionally, the return of the "Pease limitation" will cap the value of itemized deductions, reducing them by 3% of adjusted gross income (AGI) above specific statutory thresholds.
• Larger estates ($7M–$14M per person): High-net-worth individuals face a steep drop in the lifetime estate and gift tax basic exclusion amount. The TCJA doubled the base exemption (reaching $13.61 million per individual in 2024). In 2026, this reverts to approximately $7 million (adjusted for inflation), potentially subjecting the difference to a 40% federal estate tax. For current thresholds, consult the IRS Estate Tax guidelines.
• Families with multiple children: The Child Tax Credit is slated to revert from $2,000 back to $1,000 per qualifying child, resulting in a $4,000 increase in tax liability for a family with four children. Furthermore, the phase-out threshold for married couples filing jointly will plummet from $400,000 to $110,000, disqualifying many middle-to-upper-income families entirely.
• Taxpayers with ISO stock options: The TCJA significantly increased Alternative Minimum Tax (AMT) exemption amounts. When these sunset, exercising large amounts of Incentive Stock Options (ISOs) in 2026 may trigger unexpected AMT liability, as the spread between the strike price and fair market value is treated as an AMT preference item.
• Standard deduction filers: Because the TCJA nearly doubled the standard deduction, its expiration means the baseline deduction will be roughly halved. This change will force millions of taxpayers to resume tracking receipts and itemizing deductions to minimize their federal tax burden.

How Should I Prepare for the 2026 Tax Changes?

Note: This is general information, not legal advice. Tax laws and procedures vary by state and individual circumstance.

With the TCJA sunset in effect, proactive tax planning is essential. Here is a prioritized action plan to navigate the 2026 tax landscape:

Immediate (Do This Week)

• Update Form W-4: If you are an employee, your 2025 withholding was calibrated to lower TCJA rates. Under the new, higher marginal brackets, you are likely underwithholding for 2026. Complete a new W-4 immediately using the IRS Tax Withholding Estimator.
• Recalculate estimated taxes: Self-employed individuals, freelancers, and pass-through business owners must recalculate 2026 quarterly estimated payments (due April 15, June 15, September 15, and January 15) using IRS Form 1040-ES. This ensures you account for higher rates and the loss of the 20% Qualified Business Income (QBI) deduction under IRC Section 199A.
• Consult a tax attorney or CPA: If you own a business, have a significant estate, or realize substantial investment income, get a comprehensive 2026 tax projection. Failing to pay enough tax throughout the year can trigger IRS underpayment penalties under IRC Section 6654, which generally accrue at an 8% annualized rate on tax shortfalls.

Short-Term (This Month)

• Evaluate itemizing deductions: With the standard deduction roughly halved, many more taxpayers will benefit from itemizing on IRS Schedule A. Crucially, the expiration of the $10,000 State and Local Tax (SALT) cap means residents of high-tax states can once again fully deduct their property and state income taxes.
• Business entity structure review: Without the Section 199A deduction, run a C-corporation versus pass-through entity comparison. Maintaining a C-corp at the permanent 21% federal corporate rate may now be significantly more tax-efficient than pass-through taxation, where business income is taxed at the reverted 39.6% top individual rate.
• Check for AMT exposure: The TCJA significantly increased Alternative Minimum Tax (AMT) exemption amounts. With those reverting to pre-2018 levels, millions more taxpayers will be subject to AMT. If you plan to exercise Incentive Stock Options (ISOs), have significant SALT deductions, or use accelerated depreciation, run an AMT projection using IRS Form 6251.

Longer-Term (This Quarter)

• Estate plan update: The federal estate and gift tax basic exclusion amount (BEA) has dropped from over $13.6 million per individual back to approximately $7 million (adjusted for inflation). If your gross estate exceeds this threshold, meet with an estate planning attorney. Strategies like irrevocable life insurance trusts (ILITs), spousal lifetime access trusts (SLATs), annual exclusion gifting, and charitable remainder trusts have renewed importance to mitigate the 40% federal estate tax.
• Maximize pre-tax retirement contributions: Higher marginal tax brackets increase the immediate tax-saving value of traditional (pre-tax) retirement contributions over Roth contributions. Maximize your 401(k), traditional IRA, SEP-IRA, or SIMPLE IRA contributions for 2026 to strategically lower your Adjusted Gross Income (AGI).

Will Congress Extend the TCJA Before 2026?

Congress holds the constitutional authority under Article I to extend, modify, or make permanent the expiring individual provisions of the Tax Cuts and Jobs Act (TCJA). As of early 2026, active legislative debate centers on preserving middle-income tax brackets, the elevated standard deduction, and the expanded Child Tax Credit. However, taxpayers must understand the legislative realities:

• Legislative action is mandatory: Extensions are not automatic. Any continuation requires new legislation to pass both the House and Senate and be signed by the President. Because of the Senate's 60-vote legislative filibuster rule, passing comprehensive tax legislation often requires utilizing the complex budget reconciliation process.
• Deficit concerns: The Congressional Budget Office (CBO) has projected that permanently extending the TCJA's individual income and estate tax provisions would add approximately $4.6 trillion to the national deficit over a 10-year window, creating significant political hurdles for a blanket extension.
• Compromise is likely: Even if extensions pass, congressional agreement is uncertain. Renewals may be partial, phased out over time, or subject to strict income limitations. Additionally, state tax laws vary; states with "static conformity" will not automatically adopt federal tax extensions without separate state-level legislation.

The most prudent strategy is to plan for the law as it currently exists, not as it might be changed. Taxpayers should consider defensive moves now, such as accelerating income while federal brackets remain lower, delaying deductible business expenses, or utilizing the historically high lifetime estate and gift tax exemption before it reverts to pre-TCJA levels (roughly half its current value, adjusted for inflation). If Congress acts to retroactively extend provisions, a licensed tax attorney can quickly adjust your plan. Building a tax strategy around legislative speculation is risky and may result in significant IRS penalties for underpayment of estimated tax if anticipated extensions do not materialize.