The Solo 401(k), also called an individual 401(k) or one-participant 401(k), is designed for self-employed individuals with no employees (other than a spouse). It follows the same rules, contribution limits, and tax treatment as traditional 401(k) plans.
2026 Contribution Limits
- Employee deferral limit (2026): $24,500 (under age 50)
- Employer contribution: Up to 25% of net self-employment income (after self-employment tax deduction)
- Total combined limit (2026): $72,000 (employee + employer, excluding catch-up)
- Can designate contributions as Traditional (pre-tax) or Roth (after-tax)
- Roth Solo 401(k) contributions grow tax-free; qualified distributions are tax-free
- Loans permitted (up to $50,000 or 50% of vested balance, whichever is less)
Catch-Up Contribution Provisions (Employer Plans)
| Age | Catch-Up Amount (2026) | Notes |
|---|---|---|
| Under 50 | $0 | Standard deferral only |
| 50-59 | $8,000 | Standard catch-up |
| 60-63 | $11,250 | Super catch-up |
| 64+ | $8,000 | Reverts to standard catch-up |
- Roth catch-up mandate (2026): Employees earning over $150,000 in Federal Insurance Contributions Act (FICA) wages in the prior year must make catch-up contributions on a Roth (after-tax) basis only
- Those earning $150,000 or less may choose pre-tax or Roth catch-up
Exam Tip: Gotchas
- The "super catch-up" applies ONLY at ages 60-63. It does NOT apply at age 64 or above; the catch-up reverts to the standard amount. The exam may test the specific age window.