S Corporation Advantages and Disadvantages: Payroll Tax and QBI

The advantages and disadvantages of an S corporation come down to a trade: you get pass-through taxation and a way to shrink payroll taxes on owner earnings, and in exchange you accept rigid ownership rules, IRS scrutiny of your salary, weaker loss deductions than a partnership offers, and disqualification from some of the largest tax breaks available to C corporation founders. Whether the trade pays off depends on your profit level, how you plan to finance the business, and what a future exit looks like.

What You Gain

The core benefit is that the business itself owes no federal income tax on ordinary operating profit. Income, losses, deductions, and credits flow through to each shareholder’s personal Form 1040 via Schedule K-1, so profit is taxed once at individual rates rather than twice as with a C corporation.¹ Items keep their character on the way through. A long-term capital gain at the entity level is still a long-term capital gain on your return. A charitable contribution is still deductible as one.

One catch on the pass-through side: you pay tax on your share of the income whether the company distributes cash or not.² If the business reinvests profit rather than paying it out, you still owe tax on your slice.

The Payroll Tax Split

This is where the S corp earns its reputation. A sole proprietor or general partner pays self-employment tax on essentially all net business earnings: 12.4% for Social Security up to the annual wage base of $184,500 in 2026, plus 2.9% for Medicare with no cap, for a combined 15.3%.¹³ High earners add another 0.9% on wages above $200,000 single or $250,000 joint.⁴

An S corp owner who works in the business must take a W-2 salary, which is fully subject to FICA. Profit above that salary can come out as a distribution, and S corporation distributions are not subject to self-employment tax.⁵

Consider a business netting $200,000. As a sole proprietor, you’d owe roughly $28,200 in self-employment tax after the standard 92.35% adjustment. Elect S corp status, set your salary at $80,000, and FICA on that salary totals about $12,240 (employer plus employee shares combined). The remaining $120,000 comes out as a distribution with no payroll tax attached. That’s roughly $16,000 saved. Actual numbers depend on the salary you set and your total income.

The Qualified Business Income Deduction

S corporation shareholders can claim the Section 199A qualified business income deduction, worth up to 20% of qualified pass-through income.⁶ The One, Big, Beautiful Bill Act signed in July 2025 made the deduction permanent starting with the 2026 tax year, kept the 20% rate, widened the phase-in band for the income limitation to $150,000 for joint filers and $75,000 for others, and added a $400 minimum deduction for taxpayers with at least $1,000 of QBI from a business they materially participate in.

The deduction still phases out for higher-income owners of specified service businesses like law, accounting, health care, and consulting, with thresholds published annually by the IRS.⁷ Below the threshold, the math is simple; above it, most owners lean on a CPA.

What You Give Up

Rigid Ownership Rules

The eligibility rules are strict, and breaking one kills the election. The business must be a domestic corporation (or an LLC that elects corporate treatment) and must satisfy all of the following at all times:⁸

No more than 100 shareholders. Family members can elect to count as one, which softens the cap slightly, but it still blocks any business planning a broad capital raise or public offering.
Only eligible shareholders. Shareholders must be U.S. citizens, resident aliens, certain domestic trusts, or estates. Nonresident aliens, partnerships, corporations, and most LLCs cannot hold shares. A single ineligible shareholder terminates the election.
One class of stock. All outstanding shares must carry identical rights to distributions and liquidation proceeds. Voting differences among common shares are fine, but preferred stock with special dividend or liquidation rights is not.

The single-class-of-stock rule is the one that bites most often. Venture capital, angel rounds, and much of private equity depend on preferred stock with liquidation preferences. If your business needs that kind of financing, S corp status won’t work. Even convertible debt and warrants can be treated as a second class of stock if structured the wrong way.

The Reasonable Compensation Requirement

Because every dollar shifted from salary to distribution saves payroll tax, the IRS watches this closely. Any shareholder who performs more than minor services must receive W-2 wages that reflect what a comparable employer would pay for similar work.⁹ The IRS uses industry salary data, job duties, hours worked, and company revenue to test whether a salary is artificially low.¹⁰

An S corp reporting large distributions alongside a suspiciously small salary is an audit target. If the IRS reclassifies distributions as wages, the company owes back payroll taxes, interest, and penalties on the reclassified amount. The savings are real but require setting a defensible salary, documenting it, and running payroll with proper withholding every pay period. That overhead doesn’t exist for a sole proprietorship or partnership.

Higher Filing Costs and Steep Late Penalties

The corporation files Form 1120-S annually, reporting income, deductions, and each shareholder’s allocable share on Schedule K-1.² For calendar-year filers, the return is due March 15, a month earlier than individual returns.¹¹ A six-month extension is available but only extends filing, not payment.

Late-filing penalties are $255 per shareholder per month or partial month, up to 12 months.² A five-shareholder S corp filing three months late owes $3,825 even if no tax is due. For returns more than 60 days late, the minimum penalty is the lesser of tax owed or $525. Preparation fees for Form 1120-S with K-1s are meaningfully higher than for a Schedule C, and running payroll adds monthly cost on top. Those expenses cut into the payroll tax savings, especially at modest profit levels.

Restricted Fringe Benefits

S corporations cannot provide most tax-free fringe benefits to shareholders who own more than 2%. Employer-paid health insurance, group-term life insurance, and HSA contributions that would be tax-free for a regular employee are taxable wages for these shareholder-employees.¹² C corporations face no such restriction.

Health insurance premiums get partially favorable treatment. If the S corp pays the premiums and reports them on the shareholder-employee’s W-2 (in Box 1 but not Boxes 3 and 5), they escape Social Security, Medicare, and unemployment taxes.¹³ The shareholder can then claim an above-the-line deduction for the premiums on their personal return. The deduction is unavailable if the shareholder or their spouse is eligible for a subsidized employer health plan elsewhere.

Where an S Corp Loses to a Partnership

Losses pass through to shareholders, but you can only deduct them up to the total of your stock basis and your debt basis.¹⁴ Anything over that carries forward indefinitely.

The S corp basis rules are notably worse than partnership rules. In a partnership, a partner’s basis includes their share of the entity’s liabilities, including bank loans the partnership takes out. In an S corp, debt basis comes only from money you personally lend to the corporation. A loan guarantee doesn’t count.¹⁵ If the S corp borrows $500,000 from a bank and you personally guarantee it, your basis doesn’t move. You’d need to lend that money directly to the corporation to gain any debt basis.

That difference matters most for businesses that lose money early or carry significant debt. A partnership can hand its owners larger deductible losses because entity debt boosts partner basis. An S corp owner in the same economic position may have losses they can’t currently use. Distributions also reduce stock basis, and if a distribution exceeds your remaining basis, the excess is taxed as capital gain. An accurate running basis calculation is essential.

S corp income and losses must be allocated strictly in proportion to stock ownership. You cannot make special allocations to give one owner a larger share of losses or a particular type of income the way a partnership can. Every shareholder gets a pro rata slice based on percentage of shares and days held.

Property distributions carry another trap. When an S corp distributes appreciated property instead of cash, the corporation recognizes gain as if it sold the property at fair market value.¹⁶ That gain flows through to shareholders on their K-1s, creating a tax bill even though no one actually sold anything.

Where an S Corp Loses to a C Corp

Section 1202 lets shareholders of qualifying C corporations exclude up to 100% of capital gains on the sale of qualified small business stock (QSBS), potentially sheltering millions from tax. S corporation stock can never qualify, because the statute requires the issuing corporation to be a C corporation both at issuance and during substantially all of the holding period.¹⁷

This is a meaningful disadvantage for founders expecting a large exit. A C corporation founder selling $10 million in QSBS could potentially owe zero federal capital gains tax. An S corp owner selling for the same amount pays capital gains tax on the full proceeds. For high-growth startups anticipating a significant sale, the QSBS exclusion alone can outweigh years of S corp payroll tax savings. An S corporation can hold QSBS issued by another C corporation and pass the exclusion through to its shareholders, but the S corp’s own shares never qualify.

Extra Risks for Former C Corporations

Businesses that convert from C corp to S corp status carry two potential traps that don’t apply to companies formed as S corps from the start.

Built-In Gains Tax

If the corporation held appreciated assets when it converted, any gain recognized on those assets during the first five years of S corp status is subject to the built-in gains tax at the highest corporate rate, currently 21%.¹⁸ This tax hits at the entity level, on top of the income tax shareholders pay when the gain passes through. After the five-year recognition period ends, the extra tax no longer applies.

Passive Investment Income Termination

A converted C corp that still has accumulated earnings and profits must watch its passive investment income. If more than 25% of gross receipts come from passive sources like rents, royalties, dividends, or interest for three consecutive tax years, the S election terminates automatically at the start of the following year.¹⁹ Even before termination, the corporation pays a special tax on excess net passive income each offending year.²⁰ The clean fix is to distribute accumulated C corp earnings quickly after converting.

State Tax Wrinkles

Not every state fully respects the federal S election. Some states impose an entity-level income or franchise tax on S corporations, so the business pays state tax directly even while avoiding federal corporate tax. Others treat the S corp as a C corporation for state purposes, eliminating the pass-through benefit at that level. Rates and structures vary, from nominal flat fees to taxes based on net income, gross receipts, or net worth.

Multi-state businesses have to track different rules in each state they operate in. Some states require composite returns or withholding on nonresident shareholders’ distributive shares. Those obligations add compliance cost and reduce the net benefit of the election, particularly for businesses with operations or shareholders spread across several states.

How the Election Works and How It Ends

To elect S corp status, the business files IRS Form 2553, signed by every shareholder. The form is due no later than two months and 15 days into the tax year for which the election takes effect.²¹ For a calendar-year corporation, that’s March 15. Miss it and you wait another year unless you qualify for late-election relief.

Revenue Procedure 2013-30 offers a path for businesses that missed the deadline, as long as the request comes within three years and 75 days of the intended effective date, you can show reasonable cause, and all shareholders reported income consistently with S corp treatment during the gap.²²

If the corporation violates any structural requirement, the S election terminates automatically on the date of the disqualifying event, and the tax year splits into an S short year and a C short year.¹⁹ After termination, the corporation generally cannot re-elect S status for five tax years without IRS consent. That lockout means an accidental violation, such as admitting a nonresident alien shareholder, carries consequences that last far longer than the mistake itself.

1
Internal Revenue Service. S Corporations
2
Internal Revenue Service. 2025 Instructions for Form 1120-S
3
Social Security Administration. Contribution and Benefit Base
4
Internal Revenue Service. Topic No. 560, Additional Medicare Tax
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Internal Revenue Service. Shareholders Instructions for Schedule K-1 Form 1120-S
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Internal Revenue Service. Qualified Business Income Deduction
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Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
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Office of the Law Revision Counsel. 26 USC 1361 – S Corporation Defined
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Internal Revenue Service. S Corporation Employees, Shareholders and Corporate Officers
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Internal Revenue Service. FS-2008-25
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Internal Revenue Service. Publication 509 (2026), Tax Calendars
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Internal Revenue Service. Publication 15-B (2026), Employers Tax Guide to Fringe Benefits
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Internal Revenue Service. S Corporation Compensation and Medical Insurance Issues
14
Office of the Law Revision Counsel. 26 USC 1366 – Pass-Thru of Items to Shareholders
15
Internal Revenue Service. S Corporation Stock and Debt Basis
16
Office of the Law Revision Counsel. 26 USC 311 – Taxability of Corporation on Distribution
17
Office of the Law Revision Counsel. 26 USC 1202 – Partial Exclusion for Gain From Certain Small Business Stock
18
Office of the Law Revision Counsel. 26 USC 1374 – Tax Imposed on Certain Built-In Gains
19
Office of the Law Revision Counsel. 26 USC 1362 – Election, Revocation, Termination
20
Internal Revenue Service. Instructions for Form 1120-S (2025)
21
Internal Revenue Service. Instructions for Form 2553
22
Internal Revenue Service. Revenue Procedure 2013-30