Self-Employment Tax (15.3%): What It Is and How to Lower It

Short answer: Self-employment tax is a 15.3% tax on net self-employment earnings that funds Social Security and Medicare, covering the portions an employer would normally pay for a W-2 worker. In 2026, the 12.4% Social Security portion applies to net earnings up to $184,500, and the 2.9% Medicare portion applies to all net earnings with no cap. You can lower it by claiming every business deduction, since the tax is based on profit, not revenue.

The first year you are self-employed, this tax is usually the surprise. Understanding how it works — and where the legitimate levers are — helps you plan for it instead of getting blindsided.

What is self-employment tax?

Self-employment (SE) tax is the self-employed person’s version of the Social Security and Medicare taxes that are automatically withheld from a paycheck. When you work for an employer, you pay half and the employer pays half. When you work for yourself, you pay both halves.

That is why the rate feels high: it is not an extra penalty on freelancers, it is the full contribution that a W-2 worker only sees half of. The IRS explains SE tax at irs.gov.

How is the 15.3% self-employment tax broken down?

The 15.3% rate has two parts, each with its own rules for 2026.

Portion	Rate	Applies to (2026)
Social Security	12.4%	Net self-employment earnings up to $184,500
Medicare	2.9%	All net self-employment earnings (no cap)
Combined	15.3%	Net earnings up to the Social Security wage base

Two extra details matter:

• SE tax is calculated on about 92.35% of your net profit, not 100%, because of a built-in adjustment.
• High earners pay an additional 0.9% Medicare tax on earnings above $200,000 (single) or $250,000 (married filing jointly).

Who has to pay self-employment tax?

You generally owe SE tax if your net earnings from self-employment are $400 or more for the year. This includes freelancers, gig workers, independent contractors, sole proprietors, and most single-member LLC owners.

The $400 threshold is low on purpose. Even a modest side hustle can trigger SE tax, so do not assume small income is exempt.

How do I calculate self-employment tax?

The calculation follows a short sequence on Schedule SE:

1. Start with your net profit from Schedule C.
2. Multiply by 92.35% to get the amount subject to SE tax.
3. Apply 15.3% (up to the Social Security wage base; 2.9% Medicare continues above it).
4. That result is your self-employment tax.
5. Deduct half of it as an adjustment to income on your Form 1040.

For example, on $50,000 of net profit: $50,000 × 92.35% = $46,175, and $46,175 × 15.3% ≈ $7,065 in SE tax. About half of that ($3,532) is then deductible against your income tax.

When do I pay self-employment tax?

Nobody withholds SE tax for you, and that is the second surprise after the rate itself. It lands on your calendar twice — once as paperwork, once as money.

The paperwork is annual: you calculate SE tax on Schedule SE and file it with your Form 1040 after the year ends. The money is not. If you expect to owe $1,000 or more in total tax for the year, the IRS wants payments as you earn, through quarterly estimated taxes. For the 2026 tax year, those are due April 15, June 15 and September 15 of 2026, and January 15 of 2027.

Miss them and the shortfall is charged an underpayment penalty, which functions as interest rather than a flat fine — so a late payment is better than a skipped one.

Two practical notes:

• If you also hold a W-2 job, you can raise the withholding on that job instead of writing quarterly checks. Withholding is treated as paid evenly across the year, which can repair a quarter you have already missed.
• The money has to exist when the date arrives. Setting aside a fixed percentage of every client payment as it lands is the habit that makes the deadlines uneventful.

How can I legally lower my self-employment tax?

Because SE tax is based on net profit, the most direct way to reduce it is to reduce your taxable profit through legitimate deductions. Ways 1099 workers commonly lower the bill:

• Claim every business deduction. Mileage, home office, supplies, software, and insurance all shrink the profit SE tax is based on. Working through a full list of self-employed deductions once a year usually surfaces something you have been paying for and never claimed.
• Track mileage precisely. At 72.5¢ per mile for 2026, documented business miles directly cut taxable profit.
• Keep thorough receipts. Unclaimed expenses mean you are paying SE tax on money you actually spent on the business.
• Consider retirement contributions. SEP-IRA or Solo 401(k) contributions lower income tax (note: they reduce income tax, not SE tax, but are still valuable).
• Deduct half of your SE tax. This is automatic and lowers your income tax.
• Explore an S-corp election if you earn enough. At higher, stable income, an S-corporation structure can reduce the earnings subject to SE tax, though it adds payroll and compliance costs — a decision for a tax professional.

The theme is documentation. Deductions you cannot prove are deductions you cannot safely take.

What does the 15.3% actually buy?

Before you optimize this number down to the floor, it helps to know what it is buying.

SE tax is not a fee for the privilege of freelancing. It buys the same two things a W-2 worker’s payroll tax buys: Social Security coverage and Medicare eligibility. Reported self-employment earnings build work credits — you can earn a maximum of four per year, and it takes 40 credits, roughly ten years of covered work, to qualify for Social Security retirement benefits. Those same credits are what qualify you for disability coverage and what survivor benefits for your family are based on.

That has a practical consequence. Legitimate deductions lower your profit, and lowering your profit lowers both your SE tax and, at the margin, the earnings record your future benefit is calculated from. For most solo workers that tradeoff is still clearly worth taking — a deduction saves cash now at a small, distant cost. But it explains why the answer to “how do I get this to zero?” is that you should not want to.

The line to respect is the one between deducting real expenses and under-reporting real income. The first is tax planning. The second is fraud, and it quietly shrinks the retirement and disability record you are building at the same time.

Why does tracking expenses matter so much for SE tax?

Consider two freelancers who each gross $60,000. One tracks $12,000 in real business expenses; the other tracks nothing. The first is taxed on $48,000 of profit; the second on $60,000. On the difference alone, the disorganized freelancer overpays SE tax by well over a thousand dollars — for expenses they actually incurred.

Records are not busywork. They are the mechanism that keeps you from overpaying.

Keel: Invoice Maker & Receipts makes that record-keeping simple enough to actually keep up with. It captures receipts on your iPhone (the app proposes the details from a scan and you approve them), logs mileage at the 2026 IRS rate of 72.5¢ per mile, and creates invoices so your income and profit are clear. Everything is stored encrypted on your device — no bank connection, no cloud, no account — and exports as one file at tax time. Keel is not an automated bank-linked all-in-one; the honest tradeoff for that privacy is a little manual entry, which many solo workers find is a fair price for owning their data. Get Keel on the App Store.

Frequently asked questions

Is self-employment tax on top of income tax? Yes. SE tax (15.3%) funds Social Security and Medicare and is separate from federal and state income tax. Most 1099 workers owe both on the same profit, calculated on two different forms — Schedule SE for the 15.3%, and your Form 1040 for income tax. This stacking is why the common advice is to set aside 25%–30% of net income rather than just your income tax bracket.

Do I pay self-employment tax if I have a W-2 job too? Yes, on your self-employment earnings of $400 or more. Wages already taxed through your W-2 job count first toward the $184,500 Social Security wage base for 2026, so if your salary alone exceeds it, only the 2.9% Medicare portion applies to your side income. Your employer’s withholding does not cover SE tax, so you may still owe estimated payments.

Can deductions reduce my self-employment tax? Yes. Business deductions lower your net profit, and SE tax is calculated on net profit — a $1,000 deduction cuts roughly $141 of SE tax before any income tax saving. Retirement contributions, the deduction for half your SE tax, and the standard deduction all work differently: they lower income tax only, leaving the 15.3% untouched.

What is the additional Medicare tax? It is an extra 0.9% Medicare tax on combined wages and self-employment earnings above $200,000 (single) or $250,000 (married filing jointly). It applies on top of the standard 2.9% Medicare portion, is reported on Form 8959, and has no employer-paid half. These thresholds are not indexed for inflation, so more filers cross them each year.

Does forming an S-corp always cut self-employment tax? Not always. An S-corp can reduce earnings subject to SE tax at higher, stable incomes, but the IRS requires you to pay yourself reasonable compensation as W-2 wages, which is still taxed — only the remaining distributions escape. Against that you add payroll, a separate Form 1120-S return, and accounting costs. Whether it saves money depends on your numbers — consult a tax professional.

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This article is general information, not tax advice. Consult a qualified tax professional.