2026 TCJA Sunset: How Expiring Tax Provisions Change the LLC vs S Corp vs C Corp Math
Quick Answer
The Tax Cuts and Jobs Act’s individual tax provisions are set to expire after December 31, 2025, reverting top marginal rates from 37% to 39.6% and eliminating the 20% Qualified Business Income (QBI) deduction. While the C Corp flat 21% rate remains untouched, pass-through entities—LLCs and S Corps—face a materially higher effective tax burden in 2026, fundamentally reshifting the entity selection calculus for business owners nationwide.
Key Takeaways
- QBI Deduction Expiration: The 20% Section 199A deduction for pass-through income disappears, adding up to 7.4 percentage points to effective tax rates for LLC and S Corp owners earning qualified business income.
- Individual Rate Reversion: Top marginal bracket reverts from 37% to 39.6%, compounding the QBI loss—pass-through owners in the top bracket could see combined effective rates jump from ~29.6% to ~39.6%.
- C Corp Advantage Narrows Then Widens: The C Corp 21% rate is permanent under TCJA, meaning the pass-through premium shrinks dramatically—C Corps become more attractive for retained earnings and reinvestment strategies.
- S Corp Salary Strategy Still Matters: Even without QBI, S Corp reasonable salary optimization avoids self-employment tax on distributions—a savings of 15.3% on non-salary profit that LLCs taxed as sole proprietorships cannot match.
- State-Level Considerations Intensify: High-tax states like California and New York see a larger gap between C Corp and pass-through taxation post-sunset, making entity choice even more location-dependent.
- Re-evaluation Window is Now: Business owners should model both 2025 and 2026 scenarios before year-end—switching entities takes time and may have tax consequences that require advance planning.
Understanding the TCJA Sunset: What Actually Changes
The Tax Cuts and Jobs Act of 2017 (TCJA) was the most significant overhaul of the U.S. tax code in three decades. While many of its corporate provisions—most notably the flat 21% C Corporation tax rate—were made permanent, the individual and pass-through provisions were designed with a sunset date of December 31, 2025.
As of 2026, unless Congress acts to extend these provisions, the following changes take effect:
Individual Tax Rate Reversion
| Taxable Income (Single) | 2025 TCJA Rate | 2026 Reverted Rate | Change |
|---|---|---|---|
| $0 – $11,600 | 10% | 10% | No change |
| $11,601 – $47,150 | 12% | 15% | +3% |
| $47,151 – $100,525 | 22% | 25% | +3% |
| $100,526 – $191,950 | 24% | 28% | +4% |
| $191,951 – $243,725 | 32% | 33% | +1% |
| $243,726 – $609,350 | 35% | 35% | No change |
| $609,351+ | 37% | 39.6% | +2.6% |
These rate changes directly affect LLC and S Corp owners because pass-through business income is taxed at individual rates on the owners’ personal returns.
The QBI Deduction Disappears
The Section 199A Qualified Business Income deduction allowed eligible pass-through business owners to deduct 20% of their qualified business income from taxable income. This was capped based on W-2 wages paid and the unadjusted basis of qualified property.
For a business owner with $500,000 in qualified pass-through income, the QBI deduction was worth up to $100,000 in reduced taxable income—translating to roughly $37,000 in actual tax savings at the top rate.
In 2026, this deduction vanishes entirely.
What Stays the Same
- C Corp rate: The flat 21% corporate tax rate is permanent and does not expire.
- Estate tax exemption: While also set to sunset, separate from entity selection calculus.
- Standard deduction: Reverts from ~$15,000 (single) to ~$8,000, increasing taxable income for pass-through owners even further.
2025 vs. 2026: Entity-by-Entity Tax Comparison
Let’s examine how the TCJA sunset affects the effective tax burden for each entity type with a concrete example.
Scenario: $300,000 Business Net Income
Assumptions: Single filer, no dependents, reasonable salary of $120,000 for S Corp, standard deduction, no other income.
| Entity Type | 2025 Effective Tax Rate | 2026 Effective Tax Rate | Tax Increase |
|---|---|---|---|
| LLC (Sole Prop) | ~27.9% (with QBI) | ~34.1% (no QBI) | +6.2% |
| S Corp | ~25.3% (with QBI) | ~31.8% (no QBI) | +6.5% |
| C Corp | ~21% + potential double tax | ~21% + potential double tax | No change |
Detailed Breakdown: LLC Taxed as Sole Proprietorship
| Component | 2025 (TCJA) | 2026 (Post-Sunset) |
|---|---|---|
| Business income | $300,000 | $300,000 |
| QBI deduction (20%) | -$60,000 | $0 |
| Taxable income (approx.) | $234,000 | $289,000 |
| Self-employment tax (15.3%) | $21,736 | $21,736 |
| Federal income tax | ~$54,400 | ~$83,300 |
| Total federal tax | ~$76,136 | ~$105,036 |
| Effective rate | ~27.9% | ~34.1% |
Detailed Breakdown: S Corporation
| Component | 2025 (TCJA) | 2026 (Post-Sunset) |
|---|---|---|
| Salary (W-2) | $120,000 | $120,000 |
| Distribution (pass-through) | $180,000 | $180,000 |
| QBI deduction on distribution | -$36,000 | $0 |
| Payroll taxes on salary | $9,180 | $9,180 |
| Federal income tax (total) | ~$48,400 | ~$74,900 |
| Total federal tax | ~$57,580 | ~$84,080 |
| Effective rate | ~25.3% | ~31.8% |
Detailed Breakdown: C Corporation
| Component | 2025 (TCJA) | 2026 (Post-Sunset) |
|---|---|---|
| Corporate taxable income | $300,000 | $300,000 |
| Corporate tax (21%) | $63,000 | $63,000 |
| If distributed as dividends | +15-20% on dividends | +15-20% on dividends |
| If retained | 21% effective | 21% effective |
| If fully distributed | ~36.8% (double tax) | ~36.8% (double tax) |
Key Insight: For business owners who reinvest a significant portion of earnings, the C Corp’s stable 21% rate becomes considerably more attractive in 2026 compared to the 31-34% pass-through effective rates.
How Each Entity Type is Affected
LLCs Take the Biggest Hit
Single-member LLCs and multi-member LLCs taxed as partnerships benefit most from QBI and individual rate cuts. Without these provisions:
- Self-employment tax remains: LLC owners still pay 15.3% SE tax on all net earnings (above the Social Security wage base for the earnings portion)
- No QBI shield: The 20% deduction that offset high marginal rates is gone
- Lower standard deduction: More income is taxable overall
For high-earning LLCs, the combined federal effective rate jumps 6+ percentage points. In high-tax states, the picture worsens further.
S Corps Lose the QBI Advantage But Keep SE Savings
S Corporations lose the QBI deduction just like LLCs, but they retain their most powerful feature: avoidance of self-employment tax on distributions above reasonable salary.
This means:
- On $180,000 of profit distributed above a $120,000 salary, an S Corp owner saves $27,540 in SE tax (15.3% × $180,000)
- This savings is permanent and not affected by the TCJA sunset
- The S Corp remains the best pass-through vehicle for businesses earning above $60,000/year
For a deeper dive, see our LLC vs S Corp complete comparison guide.
C Corps Become the Stability Play
The C Corp’s 21% flat rate was already permanent, and the TCJA sunset doesn’t change it. What changes is the relative attractiveness:
- In 2025, pass-through owners enjoyed a ~25-28% effective rate vs. C Corp’s 21% (+ potential double tax). The gap was manageable.
- In 2026, pass-through effective rates jump to ~32-34%, making the C Corp’s 21% rate look significantly better for businesses that retain earnings.
However, the double taxation problem remains. If you distribute all profits as qualified dividends, the combined rate is ~36.8% (21% corporate + 15-20% dividend tax). C Corps win when you can defer distributions or reinvest earnings into business growth.
Learn more about this tradeoff in our S Corp vs C Corp tax implications guide.
The New Break-Even Analysis: When Does Each Entity Win?
Post-Sunset Decision Framework
| Business Profile | Best Entity (2025) | Best Entity (2026) | Why It Changed |
|---|---|---|---|
| Sole proprietor, $40K profit | LLC (QBI benefit) | LLC (still simplest) | Low income = low bracket, QBI loss minimal |
| Growing business, $100K profit | S Corp (SE tax savings) | S Corp (SE tax savings) | SE savings still dominate at this level |
| Established firm, $300K profit | S Corp (QBI + SE savings) | S Corp or C Corp | QBI gone; if retaining earnings, C Corp wins |
| High-earner, $500K+ profit | S Corp (QBI huge) | C Corp if retaining | 39.6% pass-through vs. 21% C Corp is stark |
| Tech startup, reinvesting all | C Corp (VC requirement) | C Corp (even stronger) | Rate gap widened; investors still prefer C Corp |
| Real estate holding | LLC (pass-through losses) | LLC (pass-through losses) | RE always favors pass-through for deductions |
The Retention Ratio Test
Here’s a practical formula for post-2026 entity selection:
If you retain more than 40% of earnings, the C Corp’s 21% rate likely beats pass-through rates of 32-34%, even accounting for eventual double taxation on distributed amounts.
If you distribute more than 60% of earnings, pass-through entities (especially S Corps) remain superior despite the QBI loss, because you avoid the second layer of dividend tax entirely.
Example: $400,000 profit, retaining 50% ($200,000), distributing 50% ($200,000)
| Entity | Tax on Retained | Tax on Distributed | Total Tax | Effective Rate |
|---|---|---|---|---|
| S Corp (salary $150K) | $0 (retained in basis) | ~$97,200 (on distribution) | ~$116,700 | 29.2% |
| C Corp | $42,000 (21%) | $42,000 (21%) + ~$30,000 (dividends) | ~$114,000 | 28.5% |
At a 50% retention ratio, C Corp and S Corp are nearly identical post-sunset. Shift the retention to 60%, and C Corp pulls ahead.
Strategic Responses to the TCJA Sunset
1. Re-evaluate Your Current Entity
If you’re currently an LLC or S Corp, model your 2026 tax liability with reverted rates. The QBI deduction alone could mean $20,000-$100,000+ in additional annual taxes depending on income level.
2. Consider a C Corp Conversion for High Earners
Businesses consistently earning $500,000+ and retaining significant earnings for growth should seriously evaluate C Corp status. The 21% rate on retained earnings is now a much bigger advantage.
3. Optimize S Corp Salary Before Year-End
S Corp owners should revisit their reasonable salary. A lower salary (within IRS reasonability) means more profit distributed free of SE tax—a strategy that becomes even more valuable when individual rates increase. Our LLC to S Corp conversion guide covers the transition process.
4. Accelerate Income into 2025 Where Possible
If you can recognize bonus income, finalize sales, or convert retirement distributions in 2025, the lower TCJA rates still apply. This is especially impactful for pass-through business owners.
5. Congress May Act—But Don’t Bet On It
There’s ongoing legislative discussion about extending TCJA provisions, either partially or fully. However, the fiscal cost of extension exceeds $4 trillion over a decade, making full extension unlikely. Plan for the sunset and treat any extension as a bonus.
For salary and distribution optimization strategies that work regardless of TCJA outcomes, see our LLC S Corp salary distributions tax optimization guide.
State-Level Impact: Where You Live Matters More
The TCJA sunset amplifies state tax differences because SALT (State and Local Tax) deduction limitations may also revert, but the underlying state tax rates create significant variation.
High-Tax State Impact (California Example)
| Entity | 2025 Combined Rate (Fed + CA) | 2026 Combined Rate (Fed + CA) | Increase |
|---|---|---|---|
| LLC/Sole Prop | ~37.1% | ~43.5% | +6.4% |
| S Corp | ~34.5% | ~41.2% | +6.7% |
| C Corp | ~30.6% (21% + 8.84%) | ~30.6% | No change |
In California, a C Corp owner retaining earnings pays roughly 13 percentage points less than a pass-through owner in 2026—a gap that barely existed in 2025.
No-Income-Tax State Impact (Texas/Florida)
| Entity | 2025 Federal Rate | 2026 Federal Rate | Increase |
|---|---|---|---|
| LLC/Sole Prop | ~27.9% | ~34.1% | +6.2% |
| S Corp | ~25.3% | ~31.8% | +6.5% |
| C Corp | ~21% | ~21% | No change |
Even in tax-free states, the 10+ point gap between C Corp and pass-through rates makes entity selection dramatically more consequential.
Frequently Asked Questions
Does the TCJA sunset affect the 21% corporate tax rate for C Corporations?
No. The Tax Cuts and Jobs Act made the 21% flat corporate tax rate permanent. It does not expire in 2026. This is precisely why the TCJA sunset makes C Corporations relatively more attractive—pass-through rates are rising while the C Corp rate stays flat. Business owners comparing entities should factor this asymmetry into their long-term planning.
How much more tax will an S Corp owner pay without the QBI deduction in 2026?
An S Corp owner with $300,000 in pass-through income (above reasonable salary) would lose the 20% QBI deduction worth approximately $60,000 in reduced taxable income. At the reverted 39.6% top rate, this translates to roughly $23,760 in additional federal income tax for the year. Combined with the bracket reversion itself, total additional tax burden could range from $25,000 to $40,000+ depending on the income distribution between salary and pass-through earnings.
Should I convert my LLC to a C Corp because of the TCJA expiring provisions?
It depends on your retention strategy. If your business earns $300,000+ annually and you retain 40% or more of earnings for growth, the C Corp’s permanent 21% rate becomes very compelling post-sunset. However, if you distribute most profits to owners, the C Corp’s double taxation (21% corporate + 15-20% dividend tax) will likely exceed pass-through rates. Model both scenarios using your actual income, distribution patterns, and state tax rates before deciding.
How does the expiring QBI deduction specifically affect single-member LLCs?
Single-member LLCs taxed as sole proprietorships face a double impact from the TCJA sunset: they lose both the 20% QBI deduction and face higher individual tax brackets. A single-member LLC earning $200,000 in 2025 had an effective federal rate of roughly 27-28% including self-employment tax. In 2026, that same LLC would face approximately 33-34%. Unlike S Corps, single-member LLCs cannot avoid self-employment tax through salary-distribution splitting, making the QBI loss even more painful.
What tax planning steps should pass-through business owners take before the TCJA provisions expire?
Pass-through owners should take four immediate steps: (1) model 2025 vs. 2026 tax liability to quantify the impact, (2) consider accelerating income recognition into 2025 while rates are lower, (3) evaluate whether S Corp election would reduce self-employment tax exposure, and (4) assess whether business reinvestment patterns justify a C Corp conversion. Additionally, review your reasonable salary (for S Corps) and consider maximizing retirement contributions, which reduce taxable income regardless of entity type.
Does the TCJA sunset change the self-employment tax calculation for LLCs vs S Corps?
No. Self-employment tax rates (15.3%) and the Social Security wage base are not affected by the TCJA sunset. What changes is the relative value of avoiding SE tax. In 2025, an S Corp owner saving $15,300 in SE tax on $100,000 of distributions also enjoyed QBI benefits on that income. In 2026, the SE tax savings remain but the QBI benefit is gone—making the SE tax avoidance an even larger percentage of the total tax savings from S Corp status. This strengthens the case for S Corp election for profitable LLCs.
Don’t Wait Until December: Start Your Entity Review Now
The TCJA sunset creates the most significant shift in entity selection math in nearly a decade. Whether you’re a current LLC owner wondering if an S Corp election makes sense, or a profitable business considering the C Corp path for the first time, the decisions you make in 2025 will determine your tax trajectory for years to come.
Use our comparison tools above to model your specific situation. The difference between the right entity choice and the wrong one could be $30,000, $50,000, or even $100,000+ annually in tax savings.
Ready to dive deeper? Explore our complete guides:
- LLC vs S Corp: Complete Comparison Guide
- LLC vs C Corp: Complete Comparison Guide
- When to Convert Your LLC to an S Corp
The math has changed. Make sure your entity keeps up.