A Bigger Bucket for the Self-Employed in 2026
If you run a one-person business and save for retirement on your own, the IRS just handed you a raise. The 2026 solo 401k caps are higher than 2025 across every tier, which means more room to shelter income, defer taxes, and build long-term wealth. The total ceiling now stretches past $80,000 once catch-ups kick in.
A solo 401k (also called an individual 401k or one-participant 401k) is designed for business owners with no employees other than a spouse. You wear two hats inside the plan, employee and employer, and each role has its own contribution rule. Stacked together, those two rules are why this account tends to outpace SEP IRAs and traditional IRAs for high earners.
Many self-employed savers open a solo 401k through a low-cost brokerage like Robinhood, Fidelity, or Charles Schwab. The platform you pick will not change the IRS limits, but it can affect fees, investment menus, and how easy it is to track contributions during tax season.
Robinhood
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The 2026 Employee Deferral Limit
As the employee of your own business, you can defer up to $24,500 of compensation into the plan in 2026. That is up from $23,500 in 2025. You can split this between pre-tax (traditional) and Roth dollars in any ratio your plan allows.
This $24,500 cap is per person, not per plan. If you also work a W-2 job with a 401k, the limit applies across both plans combined. Going over can trigger taxes and penalties, so track every paycheck deferral plus your solo contributions in one place.
Catch-Up Contributions by Age
The IRS gives older savers extra room, but the rules now branch by age band.
Age 50 to 59
If you are 50 or older during 2026, you can add an extra $8,000 in catch-up money. That brings your employee deferral to $32,500. Catch-ups can be pre-tax or Roth in most solo 401k plans.
Age 60 to 63
Thanks to a SECURE 2.0 update, savers ages 60 through 63 get an enhanced catch-up of $11,250 in 2026. Total employee deferral for this group is $35,750. The boost ends the year you turn 64, when you drop back to the standard $8,000 catch-up.
High earners and the Roth catch-up rule
If your prior-year wages topped $150,000, your 2026 catch-up contributions must go in as Roth, not pre-tax. Plans that do not offer Roth catch-ups may bar high earners from making any catch-up at all, so confirm with your provider before December.
The Employer Side of the Plan
Here is where the solo 401k pulls ahead of most other self-employed accounts. As the employer, your business can also kick in profit-sharing contributions on top of your employee deferral.
For sole proprietors and single-member LLCs taxed as such, the profit-sharing piece is calculated at up to 20% of net self-employment income (after the deductible half of self-employment tax). For S-corp owners paying themselves W-2 wages, the employer side is up to 25% of those wages.
The two sides combined cannot exceed the IRS overall cap.
The 2026 Total Contribution Cap
When you stack employee deferral and employer profit-sharing, the IRS sets a master ceiling. For 2026 that ceiling is $72,000 for savers under 50. Add the standard catch-up and the cap becomes $80,000. Ages 60 to 63 can hit $83,250.
A quick example: a 45-year-old freelancer earning $150,000 in net self-employment income could defer the full $24,500 as the employee, then add roughly $27,800 as the employer, landing near $52,300 total. The same setup at age 62, with maxed catch-ups, can push past $63,500.
Keep in mind that compensation that counts for these calculations is capped at $360,000 for 2026, so very high earners cannot stretch the employer piece beyond that base.
Choosing a Provider for Your Solo 401k
Not every broker offers a solo 401k, and the ones that do vary in features. Look for these basics.
- Roth solo 401k option, not just pre-tax.
- Loan provisions if you may need access before retirement.
- Low or zero account fees.
- A clear way to file IRS Form 5500-EZ once plan assets exceed $250,000.
Many self-directed investors compare platforms like Robinhood, Fidelity, Charles Schwab, and E-Trade. You can read a full breakdown in this Robinhood review if you want to see how a newer broker stacks up on cost and features.
Deadlines You Cannot Miss
- Plan establishment: by your tax filing deadline including extensions. If you file late, you may still set up the plan in early 2026 and contribute for 2025 through your business.
- Employee deferrals: must be elected by December 31, 2026, with funding deadlines that depend on your business structure.
- Employer profit-sharing: by your business tax filing deadline plus extensions, typically October 15 of the following year.
Missing the election deadline is the most common mistake. The IRS expects to see a written deferral election dated before year end, even if the money funds later.
Solo 401k vs SEP IRA in 2026
A SEP IRA also lets self-employed savers contribute up to 25% of compensation or roughly 20% of net self-employment income, capped at $72,000 in 2026. But a SEP has no employee deferral piece and no catch-up. That means a 55-year-old earning $80,000 in net self-employment can usually shelter far more in a solo 401k than a SEP.
The solo 401k also allows Roth contributions and plan loans. The SEP wins on simplicity, with no Form 5500 filing and no plan document.
Tax rules can change, so consult a tax professional for your specific situation before locking in a strategy.
Common Mistakes to Avoid
- Double-counting employee deferrals between a W-2 job and your solo plan.
- Forgetting to file Form 5500-EZ when plan assets cross $250,000.
- Mixing personal funds with plan funds.
- Treating profit-sharing as elective. It is calculated, not deferred, so you cannot run payroll on it.
- Skipping the Roth option without comparing your current vs expected future tax bracket.
Frequently Asked Questions
Can I contribute to both a solo 401k and a Roth IRA in 2026?
Yes. The solo 401k and Roth IRA have separate contribution limits. You can max your solo 401k as both employee and employer while still putting up to $7,500 into a Roth IRA if your income falls under the phase-out range.
Do I need an LLC to open a solo 401k?
No. Sole proprietors, single-member LLCs, partnerships with only spouse-owners, and S-corps can all qualify. The key requirement is that you have self-employment income and no full-time employees other than yourself or your spouse.
What happens to my solo 401k if I hire an employee?
Once you hire a non-spouse employee who meets eligibility rules, your solo 401k generally must convert into a regular 401k that covers staff, or you may need to terminate it. Plan ahead if you expect to grow beyond a one-person shop.
Are solo 401k contributions tax deductible?
Pre-tax solo 401k contributions, both the employee and employer pieces, are typically deductible against your business income. Roth contributions are not deductible up front, but qualified withdrawals in retirement can come out tax free. Tax rules can change, so consult a tax professional for your situation.
