S-Corp vs. C-Corp: Which Entity Saves Owners More?

For most active business owners generating profits below $500,000 per year, an S-corp typically produces lower total taxes than a C-corp because income passes through to individual returns and avoids double taxation. A C-corp makes more sense when owners want to retain large earnings inside the company at the flat 21% corporate rate, pursue outside investors who need equity flexibility, or position the business for a tax-advantaged exit under the qualified small business stock rules. The right answer depends on your income level, growth plans, and whether you need the QBI deduction, now permanent under the One Big Beautiful Bill Act (OBBBA).

How S-Corp and C-Corp Taxation Actually Work

The core difference between an S-corp and a C-corp is where the tax is paid.

C-corporation: The company pays federal income tax at a flat 21% rate on taxable income. When after-tax profits are distributed to shareholders as dividends, those dividends are taxed again on the shareholder’s individual return, at qualified dividend rates up to 23.8% (including the 3.8% net investment income tax). This two-layer structure is called double taxation. The combined effective federal rate on distributed C-corp earnings can reach 36 to 40%.

S-corporation: The entity pays no federal income tax at the entity level. Income, losses, deductions, and credits flow through to shareholders in proportion to ownership and are reported on individual returns. Shareholders pay tax at their ordinary income rates, which top out at 37% in 2026. However, owners can also claim the 20% Section 199A QBI deduction on qualified business income, bringing the effective top federal rate on pass-through profits closer to 29.6% for eligible taxpayers.

The Self-Employment Tax Advantage

One of the strongest reasons small business owners choose S-corps is payroll tax savings. A sole proprietor or single-member LLC owner pays self-employment tax at 15.3% on all net profit up to $184,500 in 2026, and 2.9% beyond that. An S-corp owner is required to take a reasonable W-2 salary, but distributions above that salary are not subject to payroll taxes.

For example, an owner generating $200,000 in net profit who pays themselves a reasonable salary of $100,000 owes FICA only on the $100,000 wage, not on the $100,000 distribution. That structural split can save $8,000 to $15,000 annually, depending on the salary-to-distribution ratio. The IRS closely scrutinizes S-corps that pay unreasonably low salaries, so the compensation must reflect market rates for the services the owner actually performs.

S-Corp vs. C-Corp: Key Structural Differences

Factor	S-Corp	C-Corp
Entity-level federal tax	None	21% flat
Shareholder-level tax	Ordinary income rates (up to 37%)	Qualified dividend rates (up to 23.8%)
Double taxation	No	Yes, on distributions
QBI deduction (Sec. 199A)	Yes, up to 20%	No
Maximum shareholders	100 (with family-attribution rules)	Unlimited
Allowable shareholder types	U.S. individuals, certain trusts, estates	Individuals, corporations, foreign investors
Classes of stock	One	Multiple
Qualified small business stock (QSBS)	Not eligible	Eligible
Venture or institutional equity	Rarely practical	Standard

S-Corp Eligibility Rules

To elect S-corp status with IRS Form 2553, a corporation must meet all of the following on the election date and every day thereafter:

• No more than 100 shareholders (all members of one family, up to six generations, count as one)
• Only eligible shareholders: U.S. citizens, resident aliens, certain trusts, and estates. Partnerships, corporations, and nonresident aliens are excluded.
• Only one class of stock (differences in voting rights are permitted)
• Domestic corporation, not an S-ineligible type such as a financial institution or DISC

Failing to maintain any of these requirements triggers automatic termination of S status, often with adverse tax consequences. C-corps carry none of these restrictions, making them the default structure for businesses with complex cap tables, foreign investors, or planned institutional funding.

When the S-Corp Structure Wins

Pass-Through With the 20% QBI Deduction

The OBBBA, signed July 4, 2025, made the Section 199A QBI deduction permanent. In 2026, eligible S-corp shareholders can deduct up to 20% of qualified business income from federal taxable income. Per IRS Revenue Procedure 2025-32, the 2026 phase-out ranges run from $201,750 to $276,750 for single filers and $403,500 to $553,500 for married filing jointly. The IRS publishes guidance on pass-through taxation at irs.gov/businesses/small-businesses-self-employed/s-corporations.

The OBBBA also widened the phase-in ranges above those thresholds, to $75,000 for single filers and $150,000 for joint filers, and added a minimum $400 deduction for owners with at least $1,000 of QBI who materially participate.

Specified service trade or business (SSTB) owners, including consultants, lawyers, accountants, and financial advisors, begin to lose the deduction as taxable income rises above these thresholds and lose it entirely above the upper limit. Non-SSTB businesses with significant W-2 wages or depreciable property can often claim the full deduction regardless of income level.

For an owner in the 32% bracket with $300,000 of qualified business income and no SSTB limitation, the effective federal income tax rate on that income drops from 32% to roughly 25.6% after the QBI deduction, before considering payroll tax savings.

State Pass-Through Entity Tax (PTET) Elections

Most states now allow S-corps and other pass-through entities to elect a state-level entity tax, which the business deducts as a federal business expense. This structure bypasses the individual SALT deduction cap entirely. The OBBBA raised the SALT cap to $40,400 in 2026 for individual filers, but high-income owners subject to the phase-out (beginning above $505,000 of MAGI) can still benefit from a PTET election layered on top. The IRS authorized this strategy in Notice 2020-75, and it survived OBBBA unchanged.

Accumulated Losses Flow to Owners

S-corp losses pass through to shareholders and can offset other income on the individual return, subject to basis, at-risk, and passive activity limitations. C-corp losses stay inside the corporation and only offset future corporate income, making the S-corp structure more capital-efficient for early-stage or cyclical businesses that generate losses in some years.

When the C-Corp Structure Wins

Retaining Earnings at 21%

When an owner wants to leave significant earnings inside the business to fund growth, a C-corp’s 21% flat rate can be attractive. An owner in the 37% bracket who retains $1 million inside the corporation pays $210,000 in corporate tax, compared to $370,000 if the same income passed through to the personal return. The deferral advantage is real but temporary: if and when those earnings are eventually distributed as dividends or extracted through a sale, the second layer of tax applies.

QSBS: The Exit Tax Benefit

C-corp status is often essential for businesses that qualify for the qualified small business stock (QSBS) exclusion under Section 1202. Under OBBBA changes effective for stock issued after July 4, 2025, the exclusion cap increased from $10 million to $15 million per taxpayer, and the corporate gross asset threshold increased from $50 million to $75 million. Both figures are indexed for inflation beginning in 2027.

OBBBA also introduced a tiered holding period for stock issued after July 4, 2025. A shareholder can exclude 50% of eligible gain after 3 years, 75% after 4 years, and up to 100% after 5 years. Stock issued on or before July 4, 2025 keeps the prior rule, which requires a holding period of more than 5 years for the exclusion. S-corps and their shareholders cannot access Section 1202.

Venture Capital and Complex Cap Tables

Institutional investors typically require preferred stock with liquidation preferences, anti-dilution provisions, and other terms that need multiple share classes. Because S-corps can have only one class of stock, they are practically incompatible with traditional VC funding rounds. C-corps, usually organized in Delaware, are the standard vehicle for startups pursuing outside equity.

Attracting International Shareholders

S-corps cannot have nonresident alien shareholders. Any business with global investors, foreign co-founders, or international equity plans must use a C-corp.

The LLC vs. S-Corp Dimension

Owners comparing entity structures often ask whether to use an LLC taxed as an S-corp or a C-corp. A single-member LLC is taxed as a sole proprietorship by default; a multi-member LLC is taxed as a partnership. Either can elect S-corp or C-corp treatment. Operationally, LLCs offer more flexibility in governance and profit allocation, but an LLC taxed as an S-corp must still meet all S-corp eligibility and compensation rules.

The “LLC vs S corp” question usually comes down to compliance cost and tax savings breakeven. Running S-corp payroll adds accounting and payroll processing costs. Many advisors set an informal breakeven at around $40,000 to $50,000 of net profit above a reasonable salary before the payroll tax savings justify S-corp overhead.

Modus’s tax advisory team regularly helps owners model this breakeven for their specific revenue trajectory and state tax obligations, factoring in PTET elections and the QBI deduction impact.

Head-to-Head: Which Structure Saves More by Scenario

Scenario A: $250,000 net profit, active owner, non-SSTB An S-corp owner paying a $100,000 reasonable salary saves approximately $11,000 to $13,000 in payroll taxes on distributions compared to a sole proprietor, and qualifies for a partial QBI deduction. A C-corp at 21% leaves $197,500 after entity tax, but distributing those earnings triggers qualified dividend tax, resulting in a higher combined federal burden.

Scenario B: $2 million net profit, owner retaining capital for expansion The C-corp’s 21% rate on retained earnings produces meaningful deferral versus the S-corp’s 37% pass-through rate on undistributed income. If the business will eventually sell rather than distribute dividends, and qualifies for QSBS, the C-corp exit may be tax-free up to $15 million.

Scenario C: SSTB professional firm (law, accounting, consulting) over $553,500 taxable income At this income level, the QBI deduction phases out entirely for SSTB owners. The S-corp still provides payroll tax savings on distributions, and PTET elections remain valuable, but the QBI advantage disappears. C-corp retention may be worth modeling if significant capital stays inside the business.

Implementation Considerations

Switching from C-corp to S-corp status requires filing Form 2553 and can trigger a built-in gains (BIG) tax on appreciated assets under Section 1374 for 5 years after conversion. Moving the other direction, from S-corp to C-corp, terminates the pass-through election and restarts the C-corp tax regime. Both conversions have timing and basis implications that require careful planning.

Modus’s advisory practice helps mid-market owners model multi-year scenarios before committing to a structure change, including state conformity and PTET election strategy.

Related reading: Audit Opinion Types: Unqualified, Qualified, Adverse, and Disclaimer

Frequently Asked Questions

Should my business be an S-corp or a C-corp?

For most active small business owners, an S-corp produces lower total taxes because income passes through at individual rates, avoiding the C-corp’s entity-level tax, and owners can claim the 20% QBI deduction. A C-corp is better for businesses retaining large profits at the 21% rate, seeking venture capital, or targeting a tax-free exit under the QSBS rules.

What is the main tax disadvantage of a C-corp?

Double taxation: the corporation pays 21% federal income tax on profits, and shareholders pay qualified dividend tax (up to 23.8%, including NIIT) when those after-tax profits are distributed. Combined, this can produce a 36 to 40% effective federal rate on distributed earnings.

Can an S-corp owner avoid self-employment tax?

Partially. An S-corp owner must take a reasonable W-2 salary, which is subject to FICA taxes at 15.3% up to the wage base ($184,500 in 2026) and 2.9% above it. Distributions above the salary are not subject to payroll taxes, which is the primary payroll tax savings mechanism. Setting compensation unreasonably low is a known IRS audit trigger.

Is the 20% QBI deduction still available in 2026?

Yes. The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made the Section 199A QBI deduction permanent. S-corp owners, sole proprietors, and partnership owners with qualified business income can deduct up to 20%, subject to income thresholds and SSTB rules. C-corps cannot claim the QBI deduction.

What is QSBS and why does it matter for C-corps?

Qualified small business stock (QSBS) under Section 1202 allows individual shareholders of eligible C-corps to exclude a large portion of capital gain on the sale of stock. Under OBBBA rules for stock issued after July 4, 2025, the exclusion cap is $15 million per taxpayer, the company’s gross assets must be under $75 million at issuance, and a tiered schedule applies: 50% exclusion after 3 years, 75% after 4 years, and up to 100% after 5 years. Stock issued on or before July 4, 2025 follows the prior rule of 100% exclusion after more than 5 years. S-corp shareholders cannot access Section 1202.

Can I convert my C-corp to an S-corp later?

Yes, but built-in gains (BIG) tax under Section 1374 applies to net unrealized gains on assets the C-corp held at conversion, recognized within 5 years of the S-election. Careful timing and planning of the conversion, including asset valuation at the election date, can reduce BIG tax exposure. A tax advisor should model the full multi-year impact before converting.