What Is SE Tax? Rate, 2026 Wage Base, and Penalties

Self-employment tax is the federal tax that self-employed workers pay to fund Social Security and Medicare, at a combined rate of 15.3% on net earnings. Traditional employees split those contributions with an employer; when you work for yourself, you cover both halves. For the 2026 tax year, the Social Security portion applies to the first $184,500 of net earnings, and the Medicare portion has no ceiling.

Who Owes Self-Employment Tax

You owe it if your net earnings from self-employment reach $400 or more in a tax year.¹ Net earnings means business revenue minus allowable expenses, not gross receipts. The $400 floor is low, and it applies whether self-employment is your main source of income or a sideline.

The rule reaches most people working outside a W-2 job:

Sole proprietors running an unincorporated business
Independent contractors and freelancers, including gig workers
Partners reporting their share of partnership income
Single-member LLC owners, treated the same as sole proprietors for tax purposes

Side income counts too. If you clear more than $400 in profit from a side business while holding a salaried job, that profit carries self-employment tax on top of your regular income tax. Certain church employees whose employers do not participate in Social Security are also treated as self-employed under federal tax law.²

The Rate and the 2026 Wage Base

The 15.3% rate breaks into two parts:¹

12.4% for Social Security, applied only to the first $184,500 of net self-employment earnings in 2026³
2.9% for Medicare, applied to every dollar of net self-employment earnings with no cap

Once your earnings pass $184,500, the 12.4% Social Security portion stops on the excess. The 2.9% Medicare portion keeps running.

How to Calculate What You Owe

The tax does not apply to your gross revenue. It applies to net profit after one extra adjustment. Take your net profit from the business, then multiply by 92.35% (that is, subtract 7.65%). The result is your taxable self-employment earnings, and the 15.3% rate applies to that figure.⁴ The 7.65% reduction exists because traditional employees do not pay FICA on the employer’s share of the contribution, and this adjustment gives you a comparable benefit.

On $50,000 in net profit, the math looks like this:

$50,000 × 92.35% = $46,175 in taxable self-employment earnings
$46,175 × 15.3% = $7,064.78 in total self-employment tax

Because $46,175 sits well below the $184,500 Social Security wage base, the full 15.3% applies to the entire amount. If your adjusted earnings exceeded $184,500, you would apply 12.4% only to the first $184,500 and 2.9% to everything above it.³

Deducting Half of the Tax

After the total is calculated, you can deduct half of your self-employment tax from your adjusted gross income. In the example above, that is $3,532. Schedule SE handles the calculation; the deduction flows to Schedule 1 of your Form 1040.⁵ You take the deduction whether or not you itemize. It reduces your income tax bill, though it does not reduce the self-employment tax itself.

Income That Doesn’t Count

Not every dollar you earn outside a paycheck triggers self-employment tax. Federal law carves out several categories:²

Rental income from real estate you own, unless you are in the business of dealing in real estate
Dividends and interest from investments, unless you are a securities dealer
Capital gains from selling investments or other capital assets
A limited partner’s distributive share of partnership income, though guaranteed payments for services are not excluded

These categories still carry regular income tax. They just do not add the extra 15.3%.

Quarterly Payments and the Safe Harbor

Nobody withholds tax from your self-employment income, so the IRS expects payment as you go. Estimated payments use Form 1040-ES and cover both income tax and self-employment tax.⁶ For the 2026 tax year, the four due dates are:⁷

April 15, 2026, for income earned January through March
June 15, 2026, for income earned April through May
September 15, 2026, for income earned June through August
January 15, 2027, for income earned September through December

If a date falls on a weekend or federal holiday, the deadline shifts to the next business day. You can pay through the Electronic Federal Tax Payment System (EFTPS) or IRS Direct Pay, both free, both giving you a confirmation number for your records.⁸

You avoid the underpayment penalty if any one of these is true:⁶

You owe less than $1,000 in total tax after withholdings and credits
You paid at least 90% of the current year’s tax
You paid at least 100% of last year’s tax (110% if your prior-year adjusted gross income exceeded $150,000, or $75,000 if married filing separately)⁹

When income swings from year to year, basing quarterly payments on 100% (or 110%) of last year’s total tax is the simplest way to stay inside the safe harbor.

The Forms You’ll File

Self-employment tax runs through a chain of forms, each feeding the next. Start with your income records. Form 1099-NEC reports payments from clients, and Form 1099-K reports payments processed through third-party platforms like payment apps or online marketplaces. You owe tax on all business income whether or not a form arrives for it.

The return itself moves through these:

Schedule C, where you report business income and subtract expenses to reach net profit or loss¹⁰
Schedule SE, where you apply the 92.35% multiplier and calculate the tax plus the deductible half⁵
Schedule 1, where the deduction for half of your self-employment tax lands as an adjustment to income
Form 1040, which pulls the numbers together

Receipts, mileage logs, bank statements, and invoices kept during the year make Schedule C far easier to complete when the return is due.

What Late Filing or Underpayment Costs

Missing a deadline or underpaying is expensive. The IRS charges different penalties for different failures:¹¹

Failure to file: 5% of unpaid tax per month, capped at 25%. If your return is more than 60 days late, the minimum penalty is the lesser of $525 or 100% of the tax owed.
Failure to pay: 0.5% of unpaid tax per month, capped at 25%. The rate drops to 0.25% per month once you have an installment agreement in place.
Underpayment of estimated tax: calculated on how much you underpaid, how long it stayed unpaid, and the IRS’s quarterly interest rate.¹²

Interest also accrues on any unpaid balance from the original due date at the federal short-term rate plus 3%, compounded daily. The failure-to-file penalty runs ten times the failure-to-pay penalty, so filing on time matters even in a month when you cannot pay the full amount.

1
Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
2
Office of the Law Revision Counsel. 26 USC 1402 – Definitions
3
Social Security Administration. Contribution and Benefit Base
4
Internal Revenue Service. Topic No. 554, Self-Employment Tax
5
Internal Revenue Service. Schedule SE (Form 1040)
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Internal Revenue Service. Estimated Taxes
7
Internal Revenue Service. Estimated Tax
8
Internal Revenue Service. Tax Time Guide: Use IRS Electronic Payment Options for Fast, Safe Service
9
Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
10
Internal Revenue Service. Instructions for Schedule C (Form 1040)
11
Internal Revenue Service. Topic No. 653, IRS Notices and Bills, Penalties and Interest Charges
12
Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty