Who qualifies for a Solo 401(k)?

Any self-employed individual or business owner with no full-time employees (other than a spouse). This includes freelancers, consultants, sole proprietors, single-member LLCs, and side hustlers with 1099 income, even if they also have a W-2 job.

How much can I contribute to a Solo 401(k)?

In 2026, up to $69,000 total ($23,500 as employee elective deferral + up to 25% of net self-employment income as employer contribution). If you're 50+, add $7,500 catch-up for a total of $76,500. Age 60-63 can contribute an additional $11,250 catch-up.

Is a Solo 401(k) better than a SEP IRA?

For most self-employed people, yes. A Solo 401(k) allows higher contributions at lower income levels, offers a Roth option, and allows employee catch-up contributions. A SEP IRA only allows 25% of net income (no elective deferrals), which requires $276,000+ in net income to max out.

Solo 401(k) Guide: Rules, Limits, and Who Qualifies (2026)

The Solo 401(k) is the most powerful retirement account for self-employed individuals—offering the highest contribution limits and the most flexibility, including a Roth option.

2026 Contribution Limits

Contribution Type	Under 50	Age 50-59	Age 60-63	Age 64+
Employee elective deferral	$23,500	$31,000	$34,750	$31,000
Employer profit-sharing (up to 25% of net SE income)	Up to $45,500	Up to $45,500	Up to $34,250	Up to $45,500
Total maximum	$69,000	$76,500	$69,000	$76,500

Solo 401(k) vs. SEP IRA

Feature	Solo 401(k)	SEP IRA
Max contribution (2026)	$69,000 ($76,500 if 50+)	$69,000
Employee elective deferral	Yes ($23,500)	No
Income to max out	~$200,000	~$276,000
Roth option	Yes	No
Catch-up contributions (50+)	Yes ($7,500)	No
Loan from account	Yes (up to $50K)	No
Backdoor Roth impact (pro-rata rule)	No (not an IRA)	Yes (it’s an IRA)
Complexity to set up	Medium	Very easy
Annual filing	Form 5500-EZ (if >$250K)	None
Deadline to establish	December 31 of the tax year	Tax filing deadline (with extensions)

Contribution Comparison by Income

Net SE Income	Solo 401(k) Max Contribution	SEP IRA Max Contribution
$30,000	$23,500 + $5,575 = $29,075	$5,575
$50,000	$23,500 + $9,294 = $32,794	$9,294
$75,000	$23,500 + $13,941 = $37,441	$13,941
$100,000	$23,500 + $18,587 = $42,087	$18,587
$150,000	$23,500 + $27,881 = $51,381	$27,881
$200,000	$23,500 + $37,175 = $60,675	$37,175
$276,000+	$23,500 + $45,500 = $69,000	$69,000

At $50,000 net income, a Solo 401(k) lets you save $32,794 vs. $9,294—3.5x more.

Traditional vs. Roth Solo 401(k)

Feature	Traditional	Roth
Tax on contributions	Deductible (reduces taxable income now)	After-tax (no immediate deduction)
Tax on growth	Tax-deferred	Tax-free
Tax on withdrawals	Taxed as ordinary income	Tax-free (if qualified)
Required Minimum Distributions	Yes (starting at age 73)	No (as of 2024 SECURE 2.0)
Best if	Tax rate is higher now than in retirement	Tax rate is lower now or will be higher later

Who Should Open a Solo 401(k)

Candidate	Why
Freelancer earning $30K+ from self-employment	Defers more than SEP IRA at lower income levels
Side hustler with a W-2 job	Can contribute even with employer 401(k)*
Self-employed wanting a Roth option	SEP IRA doesn’t offer Roth
Someone doing backdoor Roth IRA	SEP IRA triggers pro-rata rule; Solo 401(k) doesn’t
Spouse works in the business	Spouse can also contribute (doubles the limit)

*Total employee deferrals across all 401(k)s can’t exceed $23,500.

How to Set Up a Solo 401(k)

Step	Details
1. Choose a provider	Fidelity, Schwab, Vanguard (free), or specialized providers for Roth option
2. Apply online	Typically takes 15-30 minutes
3. Get an EIN	Free from IRS if you don’t have one (sole proprietors can use SSN)
4. Fund the account	Transfer or contribute money
5. Invest	Choose low-cost index funds
6. File Form 5500-EZ	Only required if assets exceed $250,000

Deadline: The plan must be established by December 31 of the tax year (you can fund it until your tax filing deadline).

The Bottom Line

The Solo 401(k) is the best retirement account for self-employed individuals. It allows drastically higher contributions than a SEP IRA at income levels under $200K, offers both traditional and Roth options, doesn’t interfere with backdoor Roth IRA strategies, and even allows loans from the account. If you have any self-employment income, set one up by December 31 to maximize your tax savings.