Are there IRS limits on solo 401(k) contributions for 2026?

Have more questions?

Reviewer

Casey Epton, CPA, is a Senior Tax Advisor at Deduction, where he helped design Taylor, CPAI from day one, building an AI tax agent that works seamlessly for both clients and the CPAs who verify every return.

Last updated:

Sep 2026

Yes. The IRS imposes three statutory limits on solo 401(k) contributions for 2026. Two govern how much can be added to the account in a single year; the third caps the amount of compensation used in the calculation. All figures were adjusted for cost-of-living and published in IRS Notice 2025-67.

The Three Governing Limits

1. Employee Elective Deferral Limit - IRC §402(g)

The maximum you can contribute as an employee (elective deferrals) is $24,500 for 2026. This applies regardless of how your business is structured — sole proprietor, single-member LLC, or S corporation. Contributions can be made pre-tax (traditional) or after-tax (Roth), if the plan document permits Roth.

2. Combined Annual Additions Ceiling - IRC §415(c)

The total of all contributions — employee deferrals plus employer profit-sharing contributions — cannot exceed the lesser of $72,000 or 100% of compensation for 2026. This is the hard ceiling that ultimately governs how much can go into the account in a single year.

3. Compensation Cap - IRC §401(a)(17)

Employer profit-sharing contributions are calculated as a percentage of compensation. For 2026, compensation used in that calculation cannot exceed $360,000. Compensation above this threshold is excluded from the formula.

Limit	2026 Amount	IRC Reference
Employee elective deferral	$24,500	§402(g)
Combined annual additions ceiling	$72,000	§415(c)
Compensation cap	$360,000	§401(a)(17)

Catch-Up Contributions

Participants who are age 50 or older by December 31, 2026, may contribute additional catch-up amounts above the standard limits.

Ages 50–59 and 64+: $8,000 additional elective deferral catch-up, for a maximum employee contribution of $32,500.
Ages 60–63 ("super catch-up" under SECURE 2.0): $11,250 additional elective deferral catch-up, for a maximum employee contribution of $35,750. This elevated limit applies only to this four-year age window.

2026 Roth Catch-Up Mandate. Under IRC §414(v)(7)(A), if your prior-year wages subject to FICA exceeded $150,000, all catch-up contributions must be designated as Roth. The 2025 lookback number of $150,000 will continue to rise for inflation. If your solo 401(k) plan document does not permit Roth contributions, you lose the ability to make any catch-up contributions for that year. Review your plan document before year-end.

What These Limits Mean in Practice

The employee deferral limit ($24,500) and the combined ceiling ($72,000) work together. Employer profit-sharing contributions fill the gap between the two. The size of that gap depends on business structure. For sole proprietors and single-member LLCs, the employer contribution is capped at roughly 20% of net self-employment income after the SE tax deduction. S corporation owners contribute up to 25% of W-2 wages.

Ready to optimize your tax strategy? Solo 401(k) planning is most effective when it starts before year-end. Taylor, CPAI can help you identify the right deferral approach for your income structure. Talk to Taylor, CPAI →

Have a question about your taxes?

Ask Taylor, CPAI

Become a client