One of the quieter advantages of self-employment is access to retirement accounts with contribution limits far beyond what a typical employer-sponsored 401(k) allows — and every dollar contributed reduces your taxable income today. The two most popular options for freelancers are the SEP IRA and the Solo 401(k), and the right choice depends heavily on your income level and whether you have employees.
Side-by-side comparison
| Feature | SEP IRA | Solo 401(k) |
|---|---|---|
| Who can contribute | Employer contribution only, based on net self-employment income | Both employee deferral and employer contribution |
| Contribution flexibility at low income | Lower total possible at modest income | Often higher total possible at modest income due to employee deferral |
| Setup complexity | Very simple, minimal paperwork | More setup steps, plan documentation required |
| Employees other than a spouse | Must contribute proportionally for eligible employees | Generally must have no employees other than a spouse |
| Loan option | Not available | Often available, depending on the plan provider |
Why the Solo 401(k) often wins at moderate income
Because a Solo 401(k) allows you to contribute as both the "employee" (an elective deferral, similar to a traditional workplace 401(k)) and the "employer" (a profit-sharing style contribution based on net income), freelancers with moderate net profit can often contribute significantly more to a Solo 401(k) than to a SEP IRA, which only allows the employer-side contribution.
Why some freelancers still choose the SEP IRA
- Radically simple to open and maintain — often just a short form with a brokerage
- No annual filing requirement at typical account sizes, unlike a Solo 401(k) which requires additional reporting once assets cross a certain threshold
- A strong fit for freelancers with fluctuating, unpredictable income who want maximum flexibility year to year without ongoing plan administration
How the contribution ties into your deduction picture
What if you have employees?
If your freelance business has grown to include employees beyond a spouse, a SEP IRA requires proportional contributions for all eligible employees, which can become expensive quickly. A Solo 401(k) is generally not available once you have non-spouse employees, at which point other plan types become more appropriate — a conversation worth having with a financial or tax professional as your business scales.
The bottom line
Both accounts reduce your current-year taxable income while building long-term retirement savings — the right choice depends on your income level, whether you value the Solo 401(k)'s higher potential contribution room, and how much administrative complexity you're willing to take on.
Frequently asked questions
Can I contribute to both a SEP IRA and a Solo 401(k) in the same year?
Generally you would choose one primary self-employed retirement structure per business, since combining both against the same self-employment income involves overlapping contribution limit rules — professional guidance is recommended before attempting to combine them.
Do these contributions reduce self-employment tax?
No — like the health insurance deduction, retirement contributions reduce income tax by lowering AGI, but they do not reduce the net earnings figure used to calculate self-employment tax.
What happens to the account if I go back to a W-2 job?
The account remains yours and continues to hold its existing balance; you simply stop making self-employment-based contributions once you no longer have qualifying self-employment income, and can generally roll the balance into another retirement account if desired.