If you're self-employed — freelancer, consultant, independent contractor, solopreneur, or small business owner with no employees — you have access to a retirement account most people have never heard of. The solo 401(k) allows contributions up to $70,000 in 2026, accepts Roth contributions, and lets you borrow against your balance. It beats the SEP-IRA in almost every scenario. Here's how it works.
What Is a Solo 401(k)?
A solo 401(k) — also called an individual 401(k) or one-participant 401(k) — is a full 401(k) plan for businesses with only one participant: you (and a spouse if they work in the business). It has the same contribution limits and rules as a regular employer 401(k), with two big differences: you control the plan entirely, and you can contribute as both the employee and the employer.
That dual contribution capacity is what makes it so powerful. A regular employee can contribute up to $23,500 to their 401(k) in 2026. A solo 401(k) participant can contribute that same $23,500 as the "employee" — and then add a second contribution of up to 25% of net self-employment income as the "employer." The combined total can reach $70,000.
2026 Solo 401(k) Contribution Limits
| Contribution Type | 2026 Limit | Notes |
|---|---|---|
| Employee (elective deferral) | $23,500 | Can be traditional or Roth |
| Catch-up contribution (age 50–59) | +$7,500 | Total employee = $31,000 |
| Super catch-up (age 60–63) | +$11,250 | SECURE 2.0 bonus for this age range |
| Employer profit sharing | Up to 25% of net SE income | Pre-tax only; deductible |
| Combined maximum | $70,000 | $77,500 age 50+; $81,250 age 60–63 |
Net self-employment income = gross business income minus half of self-employment taxes and business expenses. Consult a CPA for exact calculation.
Solo 401(k) vs. SEP-IRA vs. SIMPLE IRA
Most self-employed people default to a SEP-IRA because it's easier to open. But the solo 401(k) is better for the vast majority:
| Feature | Solo 401(k) | SEP-IRA | SIMPLE IRA |
|---|---|---|---|
| 2026 max contribution | $70,000 | $70,000 | $16,500 |
| Roth option | Yes | No | No |
| Loan option | Yes (up to 50% / $50k) | No | No |
| Low income contribution | Yes (up to $23,500) | Only 25% of income | Limited |
| Employees allowed | None (except spouse) | Yes | Yes |
| Setup complexity | Moderate | Easy | Moderate |
The key insight: on low income, the solo 401(k) wins. If you earn $50,000, a SEP-IRA lets you contribute roughly $9,293 (18.59% of net SE income). A solo 401(k) lets you contribute up to $23,500 employee + employer profit sharing — potentially $25,000+ total. That's a massive difference in tax savings.
The Roth Solo 401(k) Option
One of the solo 401(k)'s biggest advantages over the SEP-IRA is Roth availability. The employee portion ($23,500) can go in as Roth — meaning no tax break now, but all growth and future withdrawals are tax-free.
Unlike a Roth IRA, there's no income limit on Roth solo 401(k) contributions. High earners who are phased out of regular Roth IRA contributions can still make Roth contributions through a solo 401(k) — or consider a backdoor Roth conversion for the IRA side.
Who Qualifies for a Solo 401(k)?
You qualify if you meet two conditions:
- You have self-employment income — from freelancing, consulting, a sole proprietorship, LLC, S-corp, or any 1099 work
- You have no full-time employees (other than your spouse)
Having a regular W-2 job doesn't disqualify you. Many people have a solo 401(k) for side income while also contributing to their employer's 401(k). The employee contribution limit ($23,500) is per person across all plans, but the employer profit-sharing contribution can stack on top.
How to Open a Solo 401(k)
Most major brokerages offer solo 401(k) plans at no cost: Fidelity, Vanguard, Schwab, and TD Ameritrade all have them. Here's the process:
- Apply before December 31: You must establish the plan by the end of the tax year to make contributions for that year
- Get an EIN: You need an Employer Identification Number (free from the IRS, takes minutes online)
- Choose a brokerage and complete their solo 401(k) application
- Make contributions: Employee deferrals are due by December 31; profit-sharing contributions can be made up to your tax filing deadline (including extensions)
- File Form 5500-EZ: Only required once your plan assets exceed $250,000
One Important Limit: The $250,000 Filing Threshold
Once your solo 401(k) exceeds $250,000 in assets, you must file Form 5500-EZ with the IRS each year. It's a simple one-page form, but it's something to track. This is lower-stakes than most people fear — it's just an annual reporting requirement, not an audit trigger.
Solo 401(k) and the FIRE Connection
For anyone pursuing early retirement, the solo 401(k) is a critical tool. The ability to shelter $70,000 annually from taxation dramatically accelerates the timeline. A self-employed person consistently maxing a solo 401(k) at 25% tax savings banks $17,500+ per year in avoided taxes — money that compounds in the portfolio instead.
For retirement projections based on your target number, see how much you actually need to retire.
Frequently Asked Questions
How much can I contribute to a solo 401(k) in 2026?
In 2026, the combined maximum solo 401(k) contribution is $70,000. This includes up to $23,500 as an employee deferral (or $31,000 if age 50–59, or $34,750 if age 60–63) plus up to 25% of net self-employment income as an employer profit-sharing contribution. Both portions combined cannot exceed $70,000.
Can I have a solo 401(k) if I also have a regular W-2 job?
Yes. Having a W-2 job does not disqualify you from opening a solo 401(k) for self-employment income. However, the $23,500 employee contribution limit is per person across all 401(k) plans — not per plan. If you contribute $10,000 through your employer's 401(k), you can only contribute $13,500 more as the employee in your solo 401(k). The employer profit-sharing portion is separate and can still be contributed on top.
Is a solo 401(k) better than a SEP-IRA?
For most self-employed people, yes. The solo 401(k) offers higher contributions at lower income levels, accepts Roth contributions (SEP-IRA does not), and allows loans. The main advantage of a SEP-IRA is simpler setup and the ability to cover employees if you hire them later. If you have no employees and want maximum flexibility, the solo 401(k) is typically the better choice.
Related: FIRE and early retirement math, catch-up contributions after 50, how much you need to retire.
