What Is Self-Employment Tax? (SE Tax Explained)

When you work for an employer, Social Security and Medicare taxes are split between you and your employer — each pays 7.65%. When you're self-employed, you pay both halves yourself. This combined obligation is called the self-employment tax, and it's one of the most significant tax differences between traditional employment and freelancing.

Understanding self-employment tax is essential for accurate financial planning as an independent professional.

What Is Self-Employment Tax?

Self-employment (SE) tax is the IRS mechanism by which freelancers, sole proprietors, and independent contractors pay into Social Security and Medicare — the same programs that employed workers fund through FICA withholding.

The key difference: employees split FICA with their employer (each paying 7.65%), while self-employed individuals pay the full 15.3% themselves.

SE tax applies to your net self-employment income — that is, your business revenue minus allowable business deductions.

The Self-Employment Tax Rate

The 15.3% SE tax rate is composed of two parts:

• 12.4% for Social Security — applied to net self-employment income up to the Social Security wage base ($176,100 in 2025)
• 2.9% for Medicare — applied to all net self-employment income with no cap

If your net self-employment income exceeds $200,000 (single filer) or $250,000 (married filing jointly), an additional 0.9% Medicare surtax applies to the amount over those thresholds.

Example Calculation

Say your net self-employment income for the year is $80,000:

• SE tax base = $80,000 × 92.35% = $73,880 (you only pay SE tax on 92.35% of net income)
• SE tax = $73,880 × 15.3% = approximately $11,304

The 92.35% factor exists because the IRS allows you to reduce your net income by half of SE tax before calculating it, effectively mimicking the employer deduction that traditional employees receive.

Who Pays Self-Employment Tax?

You are generally subject to SE tax if your net self-employment income is $400 or more for the year. This threshold is low — it means even modest freelance income triggers SE tax obligations.

SE tax applies to:

• Freelancers and consultants
• Sole proprietors
• Independent contractors receiving 1099 income
• Partners in a partnership (on their distributive share of partnership income)
• LLC members taxed as sole proprietors or partnerships

It does not typically apply to shareholders of S corporations who receive distributions rather than wages (though S corp shareholders who perform services must pay themselves reasonable compensation subject to payroll taxes).

The SE Tax Deduction

There is a partial offset: the IRS allows you to deduct 50% of your SE tax from your gross income when calculating your income tax. This deduction appears on Schedule 1 (Form 1040) and reduces your adjusted gross income.

This deduction does not reduce the SE tax itself — it only reduces your income tax base. Still, it provides meaningful relief, especially at higher income levels.

Self-Employment Tax vs. Income Tax

SE tax and income tax are separate obligations — you pay both. Many freelancers are surprised to discover that their total tax bill includes:

• Federal income tax (based on taxable income and applicable brackets)
• Self-employment tax (15.3% of net SE income, up to Social Security limits)
• State income tax (in most states)

At moderate income levels, SE tax often exceeds income tax for freelancers. For example, a freelancer with $50,000 in net self-employment income might owe more in SE tax alone than in federal income tax — particularly after accounting for the standard deduction and the SE tax deduction.

How to Report and Pay Self-Employment Tax

SE tax is calculated using Schedule SE (Self-Employment Tax), which is filed as part of your annual Form 1040. The net SE income from Schedule C flows into Schedule SE.

Because the IRS expects taxes to be paid throughout the year rather than all at once in April, freelancers must include SE tax estimates in their quarterly estimated tax payments. Failing to do so can result in underpayment penalties.

Reducing SE Tax Through Retirement Contributions

Contributions to certain retirement accounts — such as a SEP-IRA, Solo 401(k), or SIMPLE IRA — reduce your net self-employment income, which in turn reduces your SE tax base.

This is one of the most effective tax-reduction strategies available to self-employed individuals and is worth exploring with a CPA if your income is substantial.

Why Real-Time SE Tax Tracking Matters

Because SE tax is a percentage of net income, it changes every time your income or deductible expenses change. A freelancer who lands a large contract mid-year could see their SE tax liability shift significantly — with no automatic withholding to handle it.

Numeris Ledger's real-time tax engine tracks your federal income tax, state income tax, and self-employment tax as your income and expenses change throughout the year. Rather than discovering a large SE tax liability in April, you always know where you stand — so you can plan, reserve, and pay on time.