Is self-employment tax the same as income tax?

No — they're completely separate taxes calculated on separate schedules. Income tax is based on taxable income (after deductions). SE tax is based on net profit from self-employment (before most deductions). You pay both. For a sole proprietor at $100,000 net profit in the 22% bracket, you might owe roughly $12,700 in SE tax and $15,000+ in income tax — total over $27,000 before state tax.

Do I owe SE tax if my business has a loss?

No. SE tax only applies to net profit from self-employment. If your Schedule C shows a loss, there's no SE tax that year. The loss may also offset other income on your 1040, reducing income tax.

Does an LLC owner pay self-employment tax?

Yes — if the LLC is taxed as a sole proprietorship (single-member LLC default) or partnership, the owner pays SE tax on their share of net profit. The LLC structure doesn't change the tax treatment; only the tax election does. An LLC that has elected S-corp status only pays FICA on the owner's W-2 salary.

What's the difference between SE tax and payroll tax?

They're the same rates (Social Security + Medicare = 15.3%), but they apply differently. Payroll tax is split between employer and employee — each pays 7.65%, for a combined 15.3%. SE tax applies when you're both: as a self-employed person, you pay the full 15.3% yourself. An S-corp owner pays payroll taxes only on their W-2 salary (split between the corporation and themselves as employee), not on the full profit.

Does SE tax count toward my Social Security benefits?

Yes. SE tax payments are credited to your Social Security earnings record, which affects your eventual retirement benefits. This is worth considering when comparing sole prop vs S-corp: a lower salary in an S-corp means lower Social Security contributions and potentially slightly lower future benefits.

How does the Additional Medicare Tax work for high earners?

If your combined wages, self-employment income, and other compensation exceeds $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Medicare tax applies to income above those thresholds. This is on top of the 2.9% Medicare component in SE tax. The Additional Medicare Tax is not deductible — unlike the regular SE tax deduction for half of the standard 15.3%.

Tax planning

Self-Employment Tax Explained: Rates, Calculation, and How to Reduce It

Self-employment tax is 15.3% on top of income tax — and it applies to every dollar of net profit for sole proprietors, LLC members, and partners. Here's how it works, what it actually costs, and the three ways to reduce it.

Written by Matt Reese, CPA · 7 min read · Published April 2026·Share on LinkedIn

Key Takeaways

Self-employment tax is 15.3% (Social Security 12.4% + Medicare 2.9%) and applies to net profit before income tax. It's separate from — and in addition to — federal and state income tax.
SE tax is calculated on 92.35% of net profit, not 100%, because the IRS allows a deduction equivalent to the employer's share.
Half of SE tax is deductible 'above the line' on your 1040 — it reduces your adjusted gross income, which is more valuable than a standard deduction.
The S-corp election is the primary tool to reduce SE tax: only the W-2 salary is subject to payroll taxes, not the distribution portion of profits.

What self-employment tax actually is

When you work for an employer, your paycheck reflects two FICA taxes: Social Security (6.2%) and Medicare (1.45%). Your employer pays a matching amount. Total: 15.3% of your wages, split evenly.

When you’re self-employed, there’s no employer to split it with. You pay both sides — the full 15.3%. On top of your federal and state income tax. That’s what self-employment tax is.

It applies to sole proprietors (Schedule C filers), single-member LLC owners (default taxation), partners in a partnership, and anyone receiving W-2 wages from a business they own. It does not apply to S-corp distributions — only to the W-2 salary an S-corp owner pays themselves.

Self-employment tax isn’t a penalty — it’s the full cost of Social Security and Medicare when there’s no employer to split it with you.

The rates and how they apply

SE tax has two components with different caps:

Social Security (12.4%): Applies to net SE income up to the Social Security wage base — $176,100 in 2025. Above that, no additional Social Security tax.
Medicare (2.9%): No cap. Applies to all net SE income at any level.
Additional Medicare Tax (0.9%): Applies to SE income over $200,000 (single) / $250,000 (married filing jointly). Not included in the standard 15.3% rate — this is extra, and not deductible.

Why 92.35%?

SE tax is calculated on 92.35% of net profit, not 100%. This adjusts for the fact that employees only pay half of FICA — the employer’s half is excluded from their wage base. The 92.35% factor gives self-employed people an equivalent adjustment. The other 7.65% is effectively the “employer share” you’re paying.

What it actually costs — real numbers

SE tax at $150,000 net profit

Net profit$150,000

SE tax base (92.35% × $150,000)$138,525

Social Security (12.4% × $138,525)$17,177

Medicare (2.9% × $138,525)$4,017

Total SE tax$21,194

Deductible half of SE tax (reduces AGI)−$10,597

Net SE tax cost after deduction≈ $13,600

Federal income tax (22% bracket, rough estimate)≈ $18,000

Combined federal tax before state≈ $31,600

At $150k in net profit, SE tax adds roughly $21k to your bill before the deduction. After the deductible half reduces your AGI, the real net cost is around $13,600 — still a substantial addition on top of income tax.

How SE tax compares at different income levels

Net profit	SE tax (sole prop)	FICA as S-corp (60% salary)	Annual SE tax savings
$80,000	≈ $10,890	≈ $6,535	≈ $4,355
$150,000	≈ $19,470	≈ $11,682	≈ $7,788
$250,000	≈ $28,640	≈ $17,184	≈ $11,456
$400,000	≈ $33,120 (SS cap)	≈ $19,872	≈ $13,248
$600,000	≈ $38,400 (SS cap)	≈ $23,040	≈ $15,360

Note: S-corp column assumes 60% of net profit as W-2 salary; savings estimates don’t account for compliance costs (~$2,000–$4,000/year) which reduce the net benefit at lower income levels.

The three ways to reduce SE tax

1. Elect S-corp status

The most powerful lever. An S-corp owner pays FICA (the equivalent of SE tax) only on their W-2 salary — not on the distribution portion of profits. A $150,000 profit split as $90,000 salary + $60,000 distribution means SE tax only on $90,000 instead of the full $150,000.

This is worth $7,000–$15,000+ per year for most profitable S-corp owners, which is why it’s worth the added compliance cost above a certain profit threshold.

2. Deduct legitimate business expenses

Every dollar of legitimate business expense that reduces net profit reduces SE tax — because SE tax is calculated on net profit. A $10,000 equipment deduction under Section 179 doesn’t just save income tax; at 15.3%, it also saves approximately $1,530 in SE tax. Deductions taken on Schedule C (home office, vehicle, equipment, retirement contributions via deductible accounts) reduce the SE tax base directly.

This is different from deductions taken on the personal return (like mortgage interest or standard deduction) — those reduce income tax but not SE tax.

3. Maximize retirement contributions

Solo 401(k) or SEP-IRA contributions reduce net SE income, which reduces SE tax. A $50,000 retirement contribution at a $200k profit level saves roughly $7,650 in SE tax (15.3% × $50,000) in addition to the income tax savings. This is why the retirement contribution is often the first move before the S-corp election at lower income levels.

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What doesn't reduce SE tax

Deductions on the personal side of the return — standard deduction, mortgage interest, child tax credits, and even the QBI deduction itself — reduce your income tax but not your SE tax. SE tax is calculated on net self-employment income before those personal deductions. Only business-level reductions (expenses, retirement contributions, or the S-corp election) reduce SE tax.

The deductible half of SE tax

One built-in relief: you can deduct half of SE tax as an above-the-line deduction on Schedule 1 of your 1040. This reduces your adjusted gross income — not just your taxable income. A lower AGI affects your eligibility for other deductions, IRA contribution limits, and various credits.

At $150,000 net profit, the SE tax is roughly $21,200. Half = $10,600 deducted from AGI. At a 24% marginal rate, that deduction is worth about $2,544 in income tax savings — partially offsetting the SE tax burden.

Planning ahead

SE tax is predictable once you know your net profit. The most effective planning happens quarterly — when you have current-year income data and can estimate where the full year is heading. If you’re in a high-profit year and still operating as a sole prop, the S-corp election question deserves a serious look.

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How to Actually Elect S-Corp Status: Form 2553, Deadlines, and What Happens Next

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Frequently asked

Questions owners actually ask

Is self-employment tax the same as income tax?: No — they're completely separate taxes calculated on separate schedules. Income tax is based on taxable income (after deductions). SE tax is based on net profit from self-employment (before most deductions). You pay both. For a sole proprietor at $100,000 net profit in the 22% bracket, you might owe roughly $12,700 in SE tax and $15,000+ in income tax — total over $27,000 before state tax.
Do I owe SE tax if my business has a loss?: No. SE tax only applies to net profit from self-employment. If your Schedule C shows a loss, there's no SE tax that year. The loss may also offset other income on your 1040, reducing income tax.
Does an LLC owner pay self-employment tax?: Yes — if the LLC is taxed as a sole proprietorship (single-member LLC default) or partnership, the owner pays SE tax on their share of net profit. The LLC structure doesn't change the tax treatment; only the tax election does. An LLC that has elected S-corp status only pays FICA on the owner's W-2 salary.
What's the difference between SE tax and payroll tax?: They're the same rates (Social Security + Medicare = 15.3%), but they apply differently. Payroll tax is split between employer and employee — each pays 7.65%, for a combined 15.3%. SE tax applies when you're both: as a self-employed person, you pay the full 15.3% yourself. An S-corp owner pays payroll taxes only on their W-2 salary (split between the corporation and themselves as employee), not on the full profit.
Does SE tax count toward my Social Security benefits?: Yes. SE tax payments are credited to your Social Security earnings record, which affects your eventual retirement benefits. This is worth considering when comparing sole prop vs S-corp: a lower salary in an S-corp means lower Social Security contributions and potentially slightly lower future benefits.
How does the Additional Medicare Tax work for high earners?: If your combined wages, self-employment income, and other compensation exceeds $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Medicare tax applies to income above those thresholds. This is on top of the 2.9% Medicare component in SE tax. The Additional Medicare Tax is not deductible — unlike the regular SE tax deduction for half of the standard 15.3%.

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Educational content only.This article is for informational purposes and does not constitute tax, legal, or investment advice. Every owner’s facts are different; consult a qualified CPA and advisor before acting. Tax and accounting services are provided through Matt Reese, CPA; investment advisory services are provided through Measured Risk Portfolios, a registered investment adviser. Matt Reese, CPA and Measured Risk Portfolios are separate entities; clients are not required to engage both.