C-Corp vs S-Corp for Small Businesses: Tax Comparison and When Each Makes Sense

Q: What's the QSBS exclusion (IRC 1202)?

Under IRC 1202, a taxpayer can exclude from income up to $10 million (or 10x their basis in the stock, whichever is greater) of gain from the sale of Qualified Small Business Stock. To qualify, all five requirements must be met:

Q: How does choosing the wrong entity structure affect my taxes?

The wrong entity can cost thousands in unnecessary taxes annually. A sole proprietor earning $120,000 pays roughly $17,000 in self-employment tax; an S-Corp paying a $70,000 reasonable salary saves approximately $7,650 in FICA on the remaining $50,000. Conversely, an S-Corp for a business earning $40,000 creates more compliance cost (payroll, separate return) than the FICA savings justify. A C-Corp creates double taxation on distributions unless the owner takes all profits as salary, which maximizes FICA.

By Yarik Yarosh, CPA ·September 5, 2026 ·6 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

The C-Corp vs. S-Corp decision is one of the most consequential tax choices a business owner makes, and it is also one of the most misunderstood. The conventional wisdom (“S-Corps are always better for small businesses”) is often wrong for high-growth businesses, businesses planning to raise capital, or businesses with exit strategies that involve selling stock. The right answer depends on the specific financial picture.

✓Key takeaway

C-Corp vs. S-Corp comparison:

S-Corp advantages:

No double taxation. Income is taxed once at the shareholder level.
SE tax savings. K-1 distributions aren’t subject to self-employment or FICA tax (only reasonable salary is).
QBI deduction. K-1 income qualifies for the 20% QBI deduction (IRC 199A) for non-SSTB businesses (or below the income threshold for SSTBs).
Loss pass-through. Losses flow to the owner’s personal return and can offset other income (subject to basis, at-risk, and passive activity limitations).

C-Corp advantages:

Flat 21% corporate tax rate (vs. individual rates up to 37%).
QSBS exclusion (IRC 1202). Up to $10 million in capital gains excluded on sale of stock held 5+ years.
Unlimited shareholders (S-Corps limited to 100, US residents/citizens only).
Multiple classes of stock (S-Corps limited to one class).
Retained earnings taxed at 21%. If the business reinvests profits rather than distributing them, the 21% rate may be lower than the owner’s individual rate.
Fringe benefits. C-Corp shareholders can receive tax-free health insurance, group term life, and other fringe benefits. S-Corp shareholders owning >2% cannot exclude these benefits.

S-Corp disadvantages:

Reasonable salary requirement (IRS scrutinizes low salaries).
100-shareholder limit.
Single class of stock only.
No QSBS eligibility.
Basis tracking required at the shareholder level.

C-Corp disadvantages:

Double taxation. Corporate income taxed at 21%, then dividends taxed at 0-23.8% at the shareholder level.
No pass-through of losses.
Accumulated earnings tax risk (IRC 531, 20% penalty on unreasonable accumulations above $250,000).
Personal holding company tax risk (IRC 541, 20% on undistributed PHC income).

When does each structure save more tax?

Hypothetical example

Round numbers. For current guidance, see IRS Form 2553 instructions. A business earns $200,000 in net profit. Comparing the total tax burden (entity + owner) in three scenarios.

Scenario 1: Owner distributes all profit.

S-Corp:

Owner salary: $70,000 (FICA: $10,710)
K-1 income: $130,000 (no FICA)
QBI deduction: $130,000 x 20% = $26,000 (NOT SSTB)
Taxable income: $200,000 - $15,000 (std ded) - $26,000 = $159,000
Income tax: approximately $28,200
Total tax: $38,910
Effective rate: 19.5%

C-Corp:

Corporate tax: $200,000 x 21% = $42,000
After-tax profit: $158,000
Dividend to owner: $158,000
Qualified dividend tax: $158,000 x 15% = $23,700
Total tax: $42,000 + $23,700 = $65,700
Effective rate: 32.9%

S-Corp wins by $26,790 (13.4% lower effective rate).

Scenario 2: Owner distributes $100,000, reinvests $100,000.

S-Corp:

Same as above (all $200,000 taxed whether distributed or not): $38,910

C-Corp:

Corporate tax on $200,000: $42,000
Dividend on $100,000 distributed: after-tax = $79,000 distributed
Dividend tax: $79,000 x 15% = $11,850
Total tax: $42,000 + $11,850 = $53,850
Plus $100,000 retained for reinvestment (already taxed at 21%)
Effective rate on distributed amount: 26.9%

S-Corp still wins, but the gap narrows to $14,940. If the retained earnings grow and are eventually extracted via a QSBS-eligible stock sale (excluded gain), the C-Corp may win over the long term.

Scenario 3: Business earns $500,000, owner at 37% bracket.

S-Corp:

Salary: $120,000 (FICA: $16,578)
K-1: $380,000
QBI deduction: $380,000 x 20% = $76,000 (but subject to W-2/UBIA limitation above $266,950/$533,900 thresholds)
Assuming QBI fully available: taxable income approximately $389,000
Income tax: approximately $88,000
Total: approximately $104,578
Effective rate: 20.9%

C-Corp:

Corporate tax: $500,000 x 21% = $105,000
After-tax: $395,000
If distributed as dividends: $395,000 x 23.8% (20% + 3.8% NIIT) = $94,010
Total: $199,010
Effective rate: 39.8%

At $500,000, S-Corp wins by $94,432. The double taxation at high income levels makes the C-Corp significantly more expensive for fully distributed earnings.

When the C-Corp wins:

The business will be sold (QSBS exclusion saves $1M+ on a $5M+ exit)
The business retains most earnings for growth (21% corporate rate < 37% individual rate on undistributed income)
The business will raise outside capital (investors want C-Corp structure)
The owner wants to accumulate wealth inside the entity and extract it through salary, benefits, and eventually a stock sale rather than annual distributions

Illustrative numbers only, not a real client and not advice for your facts.

What’s the QSBS exclusion (IRC 1202)?

Under IRC 1202, a taxpayer can exclude from income up to $10 million (or 10x their basis in the stock, whichever is greater) of gain from the sale of Qualified Small Business Stock. To qualify, all five requirements must be met:

The stock must be C-Corp stock (not S-Corp).
The corporation must be a domestic C-Corp with gross assets under $50 million at the time the stock is issued.
The stock must be held for at least 5 years.
The corporation must use at least 80% of its assets in an active trade or business (not investing, real estate, financial services, professional services, or farming).
The stock must be acquired at original issuance (not purchased on the secondary market).

The exclusion is per-taxpayer, per-company. A married couple filing jointly can exclude up to $20 million. Multiple QSBS investments can each qualify for the exclusion independently.

How does choosing the wrong entity structure affect my taxes?

The wrong entity can cost thousands in unnecessary taxes annually. A sole proprietor earning $120,000 pays roughly $17,000 in self-employment tax; an S-Corp paying a $70,000 reasonable salary saves approximately $7,650 in FICA on the remaining $50,000. Conversely, an S-Corp for a business earning $40,000 creates more compliance cost (payroll, separate return) than the FICA savings justify. A C-Corp creates double taxation on distributions unless the owner takes all profits as salary, which maximizes FICA. Switching later is possible but can trigger tax consequences: converting a C-Corp to an S-Corp subjects built-in gains to a 5-year recognition period.

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Cite this page

Yarik Yarosh, CPA. "C-Corp vs S-Corp for Small Businesses: Tax Comparison and When Each Makes Sense." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/small-business-ccorp-vs-scorp-comparison

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.