SEP IRA vs Solo 401(k) for Self-Employed Americans

If you're self-employed, the standard IRA limit is low relative to what you might want to save. Both of these plans exist to fix that, and they get there differently.

SEP IRA

Simple to open and administer, with minimal ongoing paperwork. Contributions are employer-side only, limited to the lesser of 25% of compensation or $72,000 for 2026, with a compensation cap applied.

The consequence of being employer-only: at lower income levels, the percentage limit binds hard. Earn modestly and 25% of that is a modest number, regardless of how much you'd like to contribute.

SEPs also require proportional contributions for eligible employees, which matters if you ever hire.

Solo 401(k)

Available to self-employed people with no employees other than a spouse. The structure is what makes it powerful: you contribute in two capacities. As the employee, you can make elective deferrals — up to $24,500 for 2026, plus catch-up if you're 50 or over. As the employer, you can add a profit-sharing contribution on top.

Combined contributions are subject to the same overall annual additions limit — $72,000 for 2026, excluding catch-up.

The practical effect: at lower and moderate incomes, a solo 401(k) usually allows a considerably larger contribution than a SEP, because the employee deferral isn't tied to a percentage of earnings. More paperwork, though, including a filing requirement once assets exceed a threshold.

The consequence people don't anticipate

SEP IRA balances count as pre-tax IRA money for the pro-rata rule. So if you use — or might use — the backdoor Roth strategy, a SEP can quietly make those conversions partly taxable.

A solo 401(k) doesn't create that problem, because it isn't an IRA. For higher earners who rely on backdoor Roth contributions, that's often the deciding factor rather than the contribution math.

Choosing between them

Broadly: a SEP suits someone who wants minimum administration and has income high enough that the 25% cap isn't binding. A solo 401(k) suits someone wanting maximum contribution room, Roth options within the plan, or clean backdoor Roth mechanics.

Both have deadlines for establishment and funding that differ from each other. Get those from a professional rather than guessing — missing one costs you the year.

To work out your actual self-employed net income, StatementOrganizer.com will pull it from your statements.

References

• 2026 retirement plan limits: IRAs, 401(k)s and more — First Citizens Bank
• 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 — Internal Revenue Service
• Self-employed individuals tax center — Internal Revenue Service

This article is for general education only and is not tax or investment advice. Contribution limits are stated for the 2026 tax year and change annually. Contribution calculations for self-employed individuals involve adjustments not described here, and establishment and funding deadlines differ between plan types. Consult a qualified tax professional.