I left $40,000 sitting in a checking account earning 0.01% interest for two years. I told myself I was too busy to open a retirement account. That excuse cost me years of compound growth I will never get back.
A SEP-IRA closes that exact gap. Freelancers ask what a SEP-IRA is for self-employed workers because the name sounds like something built for a corporate payroll department, not a solo 1099 contractor working from a laptop. It is not. It is one of the largest retirement deductions available to anyone who files a Schedule C.
What Is a SEP-IRA?
A SEP-IRA (Simplified Employee Pension Individual Retirement Arrangement) is a retirement account funded by employer contributions only. For a sole proprietor, you are both the employer and the employee, so you write one contribution from business profit into your own IRA.
There is no salary deferral. There is no separate employee contribution. The business makes a single deposit, and that deposit is deductible.
Compare that to a Traditional IRA, capped at $7,500 for 2026. A SEP-IRA can hold nearly ten times that amount in a strong year. Any self-employed person with net profit can open one. A day job with its own 401(k) does not disqualify you from also running a SEP-IRA off your freelance income.
How Much Can You Contribute to a SEP-IRA?
The SEP-IRA rule reads 25% of compensation. For a sole proprietor, the real number lands closer to 20% of net profit. The gap exists because the contribution reduces its own base, and the IRS math solves for that circle.
Here is the calculation, using confirmed 2026 figures:
Net profit: $100,000
Multiply by 92.35% (the self-employment tax adjustment): $92,350
Self-employment tax on that amount: about $14,129
Deductible half of self-employment tax: $7,065
Net self-employment earnings for retirement purposes: $92,935
Maximum SEP-IRA contribution: 20% of $92,935 equals $18,587
The maximum SEP-IRA contribution for 2026 is $72,000, capped by a compensation limit of $360,000.
SEP-IRA vs. Solo 401(k): Which One Fits Your Business?
A SEP-IRA wins on simplicity. A Solo 401(k) wins on total contribution room at every income level, because it stacks a $24,500 employee deferral on top of the same 20% employer contribution you would get from a SEP-IRA. The setup deadline is the only real reason to consider a SEP-IRA at all.
| Feature | SEP-IRA | Solo 401(k) |
|---|---|---|
| 2026 max contribution | $72,000 |
$72,000 (plus catch-up) |
| Employee deferral | None | Up to $24,500 |
| Effective employer rate | 20% of net profit |
20% of net profit |
| Catch-up (age 50-59, 64+) | None | $8,000 |
| Super catch-up (age 60-63) | None | $11,250 |
| Roth option | Yes, since 2023 | Yes |
| Setup deadline | Filing deadline, with extensions | Must exist by December 31 |
| Loan provision | No | Some providers allow it |
If your net profit sits under $117,500 and the Solo 401(k) December 31 setup deadline has already passed for the year, use a SEP-IRA instead. The deadline is forgiving and the form takes minutes. At this income level, the employer contribution gap between the two accounts is small enough that simplicity wins.
If your net profit runs higher, or you set up a Solo 401(k) before December 31, it puts more money to work than a SEP-IRA at the identical 20% employer contribution, plus the employee deferral stacked on top.
Does a SEP-IRA Reduce Your Self-Employment Tax?
No. A SEP-IRA contribution reduces income tax, not self-employment tax. This works the same way as the self-employed health insurance deduction: it lands on Schedule 1 as an above-the-line deduction against income tax, while self-employment tax is calculated on net profit before that deduction applies.
Confusing the two leads freelancers to over-project their tax savings. Budget the SEP-IRA deduction against income tax only.
What Is the Roth SEP-IRA?
Since 2023, SECURE Act 2.0 allows a Roth version of the SEP-IRA. You fund it with after-tax dollars, skip the current-year deduction, and take the growth out tax-free in retirement.
Custodian support remains limited. Call your brokerage before assuming they offer it.
One separate 2026 rule affects Solo 401(k) catch-up contributions, not the SEP-IRA itself. If your Solo 401(k) is sponsored by an S-corp or C-corp and your prior-year W-2 wages from that business exceeded $145,000, your catch-up contributions must be Roth, not pre-tax. Sole proprietors and partners with no W-2 wages are exempt from this rule entirely.
How Do You Open and Fund a SEP-IRA?
Who Can Open a SEP-IRA, and What Is the Employee Catch?
Any 1099 contractor with net profit can open a SEP-IRA. The catch arrives the moment you hire an employee.
If you have eligible employees, you must contribute the same percentage of compensation for them that you contribute for yourself. A 20% contribution for you means a 20% contribution for every eligible employee on payroll. That rule alone stops most freelancers with staff from using a SEP-IRA.
Solo freelancers with no employees skip this problem entirely.
When Is the SEP-IRA Contribution Deadline?
You can fund a SEP-IRA for the prior tax year up to your extended filing deadline, October 15. No other major retirement account gives you that much runway.
A freelancer who closes a strong year in December can still open and fund a SEP-IRA the following October, based on the prior year's net profit. The Solo 401(k) does not offer this option. Its plan must exist by December 31 of the tax year, even though the employer contribution itself can still be funded later.
Where Does the SEP-IRA Fit in Your Money System?
The SEP-IRA is not baseline income. Fund your tax reserve account first. Fund your emergency fund next. Pay yourself a fixed baseline salary after that.
What is left after those three steps is investable cash. That is where the SEP-IRA contribution comes from, not from money you need to cover rent next month. The full sequence lives in the Freelancer Financial Checklist.
"Uninvested cash is not neutral. It is a cost, decaying against inflation every month it sits still."— David's Rule on Idle Cash
Open the account today. Fund it before the extended deadline. Then stop thinking about it until next year.