How Self-Employment Tax Works: Schedule SE, FICA & Above-the-Line Deductions
- •Self-employment tax represents both employer and employee halves of FICA (12.4% Social Security + 2.9% Medicare = 15.3%).
- •The tax applies to 92.35% of your net business profit, not 100%.
- •You receive an above-the-line deduction on Schedule 1 for exactly 50% of the self-employment tax you pay.
1. The Anatomy of the 15.3% Self-Employment Rate
When you are an employee, your employer pays 7.65% in FICA taxes and withholds 7.65% from your paycheck. When you are self-employed (as a freelancer, sole proprietor, or partner), you are both employer and employee. Therefore, you pay the full 15.3% rate: 12.4% for Old-Age, Survivors, and Disability Insurance (Social Security) and 2.9% for Hospital Insurance (Medicare).
2. The Statutory 92.35% Net Profit Multiplier
IRC § 1402(a)(12) provides a mathematical parity adjustment: you multiply your net profit by 92.35% (0.9235) before calculating SE tax. This prevents you from paying self-employment tax on the employer portion of the tax itself.
3. Social Security Wage Base Limits
The 12.4% Social Security portion only applies up to the statutory annual ceiling: $176,100 in 2025 and $184,500 in 2026. If you have concurrent W-2 earnings, those wages count first toward the ceiling, reducing the amount of self-employment earnings subject to Social Security tax. The 2.9% Medicare portion continues on all net earnings without any ceiling.
- IRC § 1401: Rate of Self-Employment Tax
- IRC § 1402: Definitions of Net Earnings from Self-Employment
- IRS Schedule SE (Form 1040) Instructions
- SSA Fact Sheet: 2025 & 2026 Social Security Contribution Base
Frequently Asked Questions
Can I deduct health insurance if I am self-employed?
Yes. Self-employed individuals may generally claim the self-employed health insurance deduction on Schedule 1 as an above-the-line adjustment, provided they were not eligible to participate in an employer-sponsored health plan.
Does the 50% deduction lower my self-employment tax?
No. The 50% deduction reduces your Adjusted Gross Income (AGI), which lowers your federal income tax, but does not reduce the Schedule SE self-employment tax itself.