How Does Self-Employment Tax Work?

What Is Self-Employment Tax?

Self-employment (SE) tax is the self-employed equivalent of the FICA taxes paid by employees and their employers. When you are a W-2 employee, your employer pays half of your Social Security and Medicare taxes (7.65%) and withholds the other half (7.65%) from your paycheck. When you are self-employed, you are both the employee and the employer - so you pay both halves, totaling 15.3% of your net self-employment income.

The 15.3% SE tax rate consists of two components:

• 12.4% for Social Security (Old-Age, Survivors, and Disability Insurance) - applies to net earnings up to the annual wage base ($176,100 for 2025)
• 2.9% for Medicare (Hospital Insurance) - applies to all net earnings with no cap; an additional 0.9% applies to earnings above $200,000 ($250,000 for joint filers)

Source: IRS Schedule SE (Form 1040), Social Security Administration. 2025 rates.

How Self-Employment Tax Is Calculated

Self-employment tax is calculated on your net self-employment income - your business revenue minus allowable business deductions. The IRS provides a step-by-step calculation on Schedule SE (Form 1040). Here is how it works:

1. Calculate net profit or loss from Schedule C (or Schedule F for farming).
2. Multiply net profit by 92.35% (the IRS allows you to exclude the "employer half" of SE tax from the tax base). For example, if your net profit is $50,000, the SE tax base is $50,000 � 92.35% = $46,175.
3. Apply the 12.4% Social Security rate to the first $176,100 (2025) of the SE tax base. Apply the 2.9% Medicare rate to the entire SE tax base.
4. Add the two components together to get your total SE tax.
5. Deduct half of the SE tax on Schedule 1 (Line 15) as an adjustment to income - this reduces your income tax but not your SE tax.

The SE Tax Deduction: Half Is Deductible

One of the most important things to understand about SE tax is that half of it is deductible on your income tax return. This deduction is taken as an adjustment to income on Schedule 1 (Line 15), meaning you do not need to itemize to claim it. The deduction reduces your adjusted gross income and your income tax liability, but it does not reduce your SE tax itself.

The rationale behind this deduction is fairness: employees do not pay tax on the employer-paid half of their FICA taxes, so the IRS allows self-employed individuals to deduct the equivalent amount. In practice, this means your effective SE tax rate is lower than 15.3%. For someone in the 22% income tax bracket, the deduction reduces the effective SE tax rate from 15.3% to approximately 13.5%.

Source: IRS Schedule SE, Schedule 1. Effective rate after deducting half of SE tax. Assumes income tax rate based on marginal bracket.

How SE Tax Affects Quarterly Estimated Payments

Because self-employment tax is not withheld from your income like it is for employees, you must pay it through quarterly estimated tax payments. The IRS requires you to pay both your income tax and your SE tax throughout the year. If you do not make sufficient estimated payments, you may owe an underpayment penalty.

To calculate your quarterly payments:

• Estimate your annual net self-employment income
• Calculate your SE tax using Schedule SE
• Add your estimated income tax liability
• Subtract any withholding from other sources (like a partner's W-2 job)
• Divide the remaining amount by 4 for quarterly payments

The safe harbor rule: if you pay at least 100% of your prior year's tax liability (110% if your AGI was over $150,000), you will not owe an underpayment penalty, even if your current-year income is higher.

Strategies to Reduce Self-Employment Tax

Unlike income tax, SE tax does not have progressive brackets - it is a flat percentage of your net earnings (up to the wage base). However, there are legitimate strategies to reduce your SE tax burden:

• Maximize business deductions. Every dollar of deductions reduces your net SE income, which directly reduces your SE tax. This is the most powerful and straightforward strategy.
• Contribute to a retirement plan. SEP IRA, Solo 401(k), and SIMPLE IRA contributions reduce your net income for income tax purposes but do not reduce SE tax. However, the overall tax savings are still significant.
• Elect S corporation taxation. If your net income consistently exceeds $60,000-$80,000, electing S corp status can reduce SE tax. You pay yourself a "reasonable salary" (subject to SE tax) and take remaining profits as distributions (not subject to SE tax). The savings must be weighed against additional payroll costs and compliance requirements.
• Hire your spouse. If your spouse works for your business, paying them a reasonable salary shifts some income from your SE tax base to their FICA tax base - potentially reducing the overall family tax burden.

SE Tax and Net Operating Losses

If your business operates at a loss (expenses exceed revenue), you do not owe SE tax for that year. However, you also do not earn Social Security or Medicare credits for that year. The Social Security Administration uses your 35 highest-earning years to calculate benefits, so a loss year simply results in a $0 entry for that year.

Net operating losses (NOLs) can be carried forward to offset future income, reducing both income tax and SE tax in profitable years. The NOL rules changed under the TCJA - for tax years beginning after 2017, NOLs can be carried forward indefinitely but are limited to 80% of taxable income in the carryforward year.

Frequently Asked Questions