SEP IRA vs Solo 401(k) for Self-Employed — 2026 Limits
If you’re a freelancer or own a one-person business, you have access to retirement accounts that let you stash far more than the regular $7,000 IRA limit. The two main options: SEP IRA and Solo 401(k). They’re not equivalent. Here’s the real comparison in 2026.
2026 Contribution Limits
- SEP IRA: Up to 25% of net self-employment income (or ~20% of gross schedule C profit after the half-SE-tax deduction), capped at $70,000.
- Solo 401(k): Up to $23,500 in elective deferrals (or $31,000 if age 50+), plus an employer profit-sharing piece of 25% of compensation, all capped at $70,000 ($77,500 if 50+).
For the same income, Solo 401(k) usually allows higher contributions because of the elective-deferral piece — especially for lower- and middle-income self-employed.
Example: $80,000 Net Self-Employment Income
- SEP IRA max: ~$14,900 (20% of $74,696 after half-SE-tax deduction)
- Solo 401(k) max: $23,500 + ~$14,900 = ~$38,400
The Solo 401(k) lets you shelter $23,500 more than the SEP IRA at this income level.
Setup Complexity
- SEP IRA: 5-minute setup at any IRA custodian (Vanguard, Fidelity, Schwab). Form 5305-SEP. No annual filings. No upfront fees at major brokerages.
- Solo 401(k): More paperwork to establish (one-time plan document setup). At a major broker, this is still relatively simple but takes a few days. Once assets exceed $250,000, you must file Form 5500-EZ annually with the IRS.
Other Trade-Offs
| Feature | SEP IRA | Solo 401(k) |
|---|---|---|
| Roth option | No (Traditional only) | Yes, Roth Solo 401(k) available |
| Loans from account | No | Yes, up to $50k or 50% of balance |
| Backdoor Roth IRA friendly | No (pro-rata problem) | Yes, doesn’t trigger pro-rata |
| Employees? | Must contribute equally for any eligible employee | Disallowed once you have employees (other than spouse) |
| Contribution deadline | Tax filing deadline + extensions | Plan must be established by year-end; contributions by tax deadline |
The “Backdoor Roth Problem”
If you do backdoor Roth IRA conversions, having a SEP IRA balance creates a tax mess called the pro-rata rule — the conversion becomes partially taxable based on the ratio of pre-tax to after-tax IRA assets.
The Solo 401(k) doesn’t have this problem because it’s not an IRA. High-earners who want backdoor Roth flexibility should choose Solo 401(k).
The Spousal Add-On
If your spouse works in the business (even part-time), they can also contribute to a Solo 401(k) — effectively doubling household retirement contributions. SEP IRAs allow this too, but the employer contribution must be the same percentage for every “employee” (you and spouse).
When to Choose Each
- SEP IRA wins if: You want simplicity, hate paperwork, have a side hustle making under $40k a year and just want a tax break.
- Solo 401(k) wins if: You earn $40k+ from self-employment and want to max out contributions, want Roth option, or do backdoor Roth conversions.
What About SIMPLE IRA?
SIMPLE IRA exists too, with a $16,500 limit (2026) plus 3% employer match. It’s mostly for slightly larger small businesses (2–10 employees). For pure solopreneurs, Solo 401(k) or SEP IRA almost always beats SIMPLE.
Bottom Line
For most one-person businesses earning over $40k, the Solo 401(k) is the right account in 2026 — higher contribution potential, Roth option, no IRA-conversion conflicts. Set it up at Fidelity, Schwab or Vanguard with no recurring fees.