SEP IRA vs Solo 401(k): Best Retirement Account for Self-Employed

If you're self-employed — freelancer, consultant, contractor, small business owner — you have access to retirement accounts with far higher contribution limits than salaried employees. Most people with a 1099 don't fully use them. That's an expensive oversight.

The two main options: the SEP IRA and the Solo 401(k). They're not equally good for everyone.

SEP IRA: Simple, High Limits

SEP-IRA (Simplified Employee Pension) lets you contribute up to 25% of net self-employment income, capped at $70,000 in 2026.

Pros:

  • Extremely simple to open and maintain (most brokers have online setup in 20 minutes)
  • Contributions can be made up to tax-filing deadline (including extensions)
  • No annual filing requirements until assets exceed $250,000

Cons:

  • Contributions are employer-only (you contribute as the business, not as an employee)
  • Lower effective limit at lower income levels
  • If you have employees, you must contribute the same percentage for all eligible employees — this makes SEP IRAs impractical for businesses with staff

Solo 401(k): Higher Limits at Lower Incomes

Solo 401(k) (also called Individual 401k or i401k) allows two types of contributions:

  1. Employee contribution: Up to $23,500 in 2026 ($31,000 if 50+)
  2. Employer contribution: Up to 25% of net self-employment income

Combined max: $70,000 ($77,500 if 50+) in 2026

The Key Difference: Why Solo 401(k) Wins at Lower Incomes

With a SEP IRA, all contributions are employer contributions (25% of income). With a Solo 401(k), you first make the full employee contribution before adding the employer percentage.

Example: $60,000 in net self-employment income

Account Calculation Max contribution
SEP IRA 25% × $60,000 $15,000
Solo 401(k) $23,500 employee + 25% × $60,000 $38,500

At $60,000 income, the Solo 401(k) lets you shelter $23,500 more than the SEP IRA.

The SEP IRA only "catches up" to Solo 401(k) limits at very high income levels (roughly $186,000+), where the 25% employer contribution alone fills the $70,000 cap.

Which Account Type Inside?

Both offer Traditional (pre-tax) versions. Solo 401(k)s can also be Roth — contributions are after-tax but growth and withdrawals are tax-free. This is a significant advantage if you expect higher taxes in retirement.

SEP IRAs are pre-tax only.

Complexity and Administration

SEP IRA: Open online in minutes, no annual filing, minimal paperwork. If you're self-employed and want the easiest possible setup, this is it.

Solo 401(k): Must be established by December 31 of the tax year (contribution deadline is still the filing deadline). Requires an IRS Form 5500-EZ once assets exceed $250,000. Slightly more paperwork. Still manageable for most people.

When to Choose Each

Situation Better choice
High income ($150k+ net SE income) Either — limits are similar
Lower income ($40k–$120k net SE income) Solo 401(k) — dramatically higher limits
Want Roth option Solo 401(k) only
Have employees SEP IRA (or consider SIMPLE IRA)
Want absolute simplicity SEP IRA
50+ and want catch-up Solo 401(k) — $7,500 catch-up vs $0 for SEP

The Bottom Line

  • Solo 401(k) is better for most self-employed people earning under $150,000/year — dramatically higher limits
  • SEP IRA is simpler, requires less setup, and works fine at higher incomes
  • Solo 401(k) has a Roth option; SEP IRA does not
  • Both let you contribute until your tax-filing deadline — use that flexibility to optimize your contribution after knowing your final income

Use our Retirement Calculator to model how maximizing your self-employed retirement contributions affects your retirement age and balance.

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