Self-Employment Tax: What It Is and How to Reduce It

Business Taxes · SELF-EMPLOYED

Self-employed individuals pay both the employee and employer share of Social Security and Medicare — 15.3% on top of income tax. Here's what it is, how it's calculated, and legal ways to reduce it.

When you work for an employer, your Social Security and Medicare taxes are split — you pay 7.65% and your employer pays another 7.65%. When you're self-employed, you pay both sides: 15.3% on the first $177,000 (2025) of net earnings and 2.9% on everything above that. This is called self-employment (SE) tax, and it surprises many new business owners. The good news: there are legitimate strategies to reduce it.

How Self-Employment Tax Is Calculated

SE tax applies to your net self-employment income — gross income minus business deductions. The calculation works in two steps:

1. Multiply net profit by 92.35% (this accounts for the employer-equivalent deduction)
2. Apply 15.3% to the result up to $177,000 (2025 Social Security wage base), then 2.9% on anything above

The Additional Medicare Tax (0.9%) also applies if your total earned income exceeds $200,000 (single) or $250,000 (married filing jointly).

Example: $80,000 net profit → $80,000 × 92.35% = $73,880 → $73,880 × 15.3% = $11,304 in SE tax.

The Deduction for Half of SE Tax

Congress built in a partial offset: you can deduct half of your SE tax as an above-the-line deduction on your Form 1040. This reduces your adjusted gross income — not your SE tax itself, but your income tax bill. In our example above, you'd deduct $5,652 ($11,304 ÷ 2), saving you money at your marginal income tax rate. This deduction is automatic — it appears on Schedule SE and flows to Schedule 1.

Strategy 1: Maximize Business Deductions

Every dollar you reduce your net profit reduces both income tax and SE tax. This makes deductions doubly valuable for the self-employed. Common areas where self-employed individuals leave money on the table:
• Home office — if you work from home, claim the deduction
• Vehicle mileage — use a mileage log; 70 cents/mile in 2025 adds up fast
• Health insurance premiums — 100% deductible above-the-line
• Retirement contributions — SEP-IRA, SIMPLE IRA, or Solo 401(k)
• Professional development, subscriptions, software

Strategy 2: Elect S Corporation Status

An S corporation does not eliminate SE tax — it restructures it. As an S corp owner-employee, you pay yourself a 'reasonable salary,' which is subject to payroll taxes (equivalent to SE tax). But profits above your salary are distributed as S corp distributions, which are NOT subject to SE tax.

Example: $150,000 net profit. As a sole proprietor, you pay SE tax on ~$138,525. As an S corp paying yourself $90,000 in salary, you pay payroll taxes only on $90,000 — potential savings of $9,000+ in SE tax annually.

S corp elections come with administrative costs and complexity. This strategy typically makes sense when net profit consistently exceeds $60,000–$80,000.

Strategy 3: Contribute to a Retirement Plan

Contributions to a SEP-IRA, SIMPLE IRA, or Solo 401(k) reduce your net self-employment income — which reduces both income tax and SE tax. For 2025:
• SEP-IRA: contribute up to 25% of net self-employment income, max $70,000
• Solo 401(k): up to $23,500 employee contributions + 25% employer contributions, max $70,000
• SIMPLE IRA: up to $16,500 ($20,000 if age 50+)

Retirement plan contributions are one of the most powerful tax-reduction tools available to the self-employed.

Frequently Asked Questions

I'm a freelancer. Do I owe SE tax even if I also have a regular W-2 job?

Yes. SE tax applies to your net freelance income regardless of what you earn at your day job. However, the Social Security portion (12.4%) only applies until your combined earnings (W-2 + self-employment) reach $177,000. Your employer's W-2 withholding counts toward this limit.

Can I avoid SE tax by treating my business income as 'passive'?

Generally no. The passive income exclusion applies to limited partners and certain passive investors. Active business owners — even single-member LLC members who manage the business — owe SE tax. The IRS scrutinizes arrangements designed to reclassify active income as passive.

When is the S corp election not worth it?

Below about $60,000 in net profit, the SE tax savings are often offset by the cost of running payroll, filing a corporate return (Form 1120-S), and state fees. S corps also require a reasonable salary — you can't pay yourself zero. An enrolled agent or CPA can run the numbers for your specific situation.

Does the QBI deduction reduce SE tax?

No. The Section 199A QBI deduction reduces your income tax, not your self-employment tax. SE tax is calculated separately on Schedule SE before the QBI deduction is applied.