Can I have a Solo 401(k) and a SEP IRA at the same time?

Generally not at the same time for the same business, as the contribution limits apply across plans. However, someone with a W-2 job and self-employment income may be able to maintain a Solo 401(k) for their self-employment income. The rules are specific to the type of SEP IRA setup, so consulting a financial planner or tax advisor before combining plans is advisable.

What Retirement Plan Is Right for My Business? (2026 Guide)

Jun 1

Written By Max Novak

By Novak Financial Partners · Updated April 2026

Key takeaways

The right plan depends primarily on whether you have employees, how much you want to contribute, and how much administrative complexity you are willing to manage
For self-employed individuals with no employees, the Solo 401(k) allows the highest contributions: up to $72,000 in 2026 ($80,000 if age 50 or older)
The SEP IRA is simpler to set up but limited to 25% of compensation, capped at $72,000, with no catch-up contributions
The SIMPLE IRA is designed for businesses with employees and requires mandatory employer matching
A Safe Harbor 401(k) lets small business owners maximize contributions without failing nondiscrimination testing
High-income business owners close to retirement should explore a defined benefit plan, which can allow contributions well above $100,000 per year

Business owners have more retirement savings options than W-2 employees, and significantly higher contribution limits. The challenge is knowing which plan fits your situation.

The answer depends on a few practical questions: Do you have employees? How much do you want to contribute each year? How much administrative work are you willing to manage? This article walks through the four main options, updated for 2026 limits, and helps you figure out which one fits.

Solo 401(k)

Best for: self-employed individuals and business owners with no full-time employees other than a spouse

The Solo 401(k), also called an individual 401(k), is the most powerful retirement savings vehicle available to self-employed individuals. It allows you to contribute as both the employee and the employer, which is what makes the limits so high.

2026 Solo 401(k) contribution limits

Employee deferral (under 50)	$24,500
Employee deferral (age 50 and older)	$32,500
Employee deferral (ages 60 to 63, SECURE 2.0)	$35,750
Employer profit-sharing	Up to 25% of net SE income
Total limit (under 50)	$72,000
Total limit (age 50 and older)	$80,000
Total limit (ages 60 to 63)	$83,250

The Solo 401(k) is especially powerful at lower income levels. A freelancer earning $80,000 can contribute $24,500 as the employee deferral plus roughly $18,500 as the employer profit-sharing contribution, for a total of about $43,000. A SEP IRA for the same person would cap at roughly $18,500. That gap is meaningful over a decade.

What else to know

Roth contributions are available on the employee deferral portion
Plan loans of up to $50,000 are permitted
If plan assets exceed $250,000, you must file Form 5500-EZ annually
Cannot have full-time employees other than a spouse
Must be established by December 31 of the tax year (though contributions can be made by the filing deadline including extensions)

Mega backdoor Roth: If your Solo 401(k) plan document allows after-tax contributions and in-plan Roth conversions, you can make after-tax contributions beyond the standard employee deferral, up to the total $72,000 plan limit, and convert those after-tax contributions to Roth inside the plan. Not all providers support this, so confirm when choosing your plan. Solo 401(k) balances also sit inside the plan rather than in an IRA, which means they do not interfere with backdoor Roth IRA contributions you make separately.

SEP IRA

Best for: self-employed individuals or small business owners who want minimal paperwork and flexible contribution amounts

The SEP IRA (Simplified Employee Pension) is the simplest retirement plan to establish. Setup requires a single IRS form. There is no annual filing requirement until plan assets exceed $250,000. Contributions are entirely discretionary, which means you can contribute a lot in a good year and skip entirely in a slow one.

2026 SEP IRA contribution limits

Maximum contribution	$72,000
Contribution rate (employees)	Up to 25% of compensation
Contribution rate (self-employed)	Up to ~20% of net SE income
Catch-up contributions	None

The main tradeoff versus a Solo 401(k) is that a SEP IRA has no catch-up contributions and no Roth option (though SECURE 2.0 authorized SEP Roth contributions, few custodians support it as of 2026). For higher earners who are 50 or older and want to maximize savings, the Solo 401(k) is typically the better choice.

The pro-rata rule: SEP IRA balances count as traditional IRA balances for IRS purposes. If you want to make backdoor Roth IRA contributions, your SEP IRA balance is included in the pro-rata calculation and part of the conversion becomes taxable. Business owners who need clean backdoor Roth access are generally better served by a Solo 401(k).

If you have employees: SEP IRA contributions must be made at the same percentage for all eligible employees as you contribute for yourself. If you contribute 20% of your own income, you must contribute 20% for every eligible employee. This can make the SEP IRA expensive for businesses with staff, since you cannot limit it to just the owner.

SIMPLE IRA

Best for: small businesses with up to 100 employees that want to offer a retirement benefit with low administrative cost

The SIMPLE IRA (Savings Incentive Match Plan for Employees) allows both employees and the employer to contribute. It is designed for businesses with up to 100 employees. Setup is straightforward and administrative requirements are minimal compared to a traditional 401(k).

2026 SIMPLE IRA contribution limits

Employee deferral limit	$17,000
Catch-up (age 50 and older)	$4,000 (total: $21,000)
Catch-up (ages 60 to 63, SECURE 2.0)	$5,250 (total: $22,250)
Small employer limit (25 or fewer employees)	$18,100 (catch-up: $3,850 for 50+)
Required employer contribution	Match up to 3% of pay, or 2% nonelective for all employees

The key distinction from a SEP IRA is that the SIMPLE IRA requires mandatory employer contributions. You cannot skip them in a slow year. This predictability can be useful for employees but makes cash flow planning more important for the business owner.

One important restriction: A SIMPLE IRA must be established between January 1 and October 1 of the year you want it to take effect. If you are considering one for 2026 and have not set it up yet, check the calendar before assuming you can still do it this year.

Backdoor Roth and the pro-rata rule: SIMPLE IRAs do not allow after-tax contributions or in-plan Roth conversions. If you want to make backdoor Roth IRA contributions, your SIMPLE IRA balance is included in the pro-rata calculation and can create an unexpected tax bill. The same applies to SEP IRAs. A Solo 401(k) or Safe Harbor 401(k) avoids this issue.

Safe Harbor 401(k)

Best for: small businesses with employees where the owner wants to maximize their own contributions without plan testing complications

A standard 401(k) with employees is subject to IRS nondiscrimination testing, which limits how much highly compensated employees (including the owner) can contribute if lower-compensated employees do not participate enough. A Safe Harbor 401(k) bypasses this testing entirely by requiring mandatory employer contributions.

The employer must contribute one of the following: a dollar-for-dollar match of employee contributions up to 3% of pay plus 50 cents on the dollar for the next 2%, a matching contribution of up to 4% of pay, or a nonelective contribution of 3% for all eligible employees regardless of whether they contribute. In exchange, the plan automatically passes nondiscrimination testing.

Employee contribution limits match the standard 401(k): $24,500 for 2026 ($32,500 if age 50 or older, $35,750 for ages 60 to 63). The total plan limit including employer contributions is $72,000 ($80,000 or $83,250 with catch-up). Administrative requirements are higher than a SEP or SIMPLE IRA, so this option typically makes more sense once a business has grown past a handful of employees.

Defined benefit plan

Best for: high-income self-employed individuals or business owners in their 50s or 60s who want to maximize contributions beyond what a Solo 401(k) allows

A defined benefit plan is a pension plan that you fund yourself. Rather than contributing up to a fixed dollar cap, contributions are determined actuarially based on the benefit you want to receive at retirement, your age, and your income. For a high-earning business owner in their late 50s, this can result in allowable contributions well above $100,000 per year.

The tradeoff is administrative complexity. These plans require an actuary to calculate annual contribution requirements, must file Form 5500 each year, and once established, contributions are generally required on a fixed schedule. This is not a set-it-and-skip-it plan. It works best for someone with consistently high income who is committed to the contribution schedule.

Combining a defined benefit plan with a Solo 401(k): Some high-income business owners use both simultaneously. The Solo 401(k) covers the employee deferral and profit-sharing contribution, and the defined benefit plan layers additional tax-deductible contributions on top. This approach requires careful planning and professional coordination but can produce very large combined deductions.

Side-by-side comparison (2026)

	Solo 401(k)	SEP IRA	SIMPLE IRA	Safe Harbor 401(k)
Best for	Solo owner, no employees	Simple setup, flexible funding	Small business with staff	Owner has employees, wants to maximize contributions
2026 max (under 50)	$72,000	$72,000	$17,000	$72,000
Catch-up (50+)	$8,000 (total $80,000)	None	$4,000 (total $21,000)	$8,000 (total $80,000)
Roth option	Yes	Limited	No	Yes
Employer contribution	Discretionary	Discretionary	Required (2% or 3% match)	Required (3% or 4%)
Employees allowed	No (spouse only)	Yes	Yes (up to 100)	Yes
Admin complexity	Low	Very low	Low	Moderate

Contribution limits reflect 2026 IRS guidance. SEP IRA maximum assumes sufficient compensation to reach the cap. Actual contribution amounts depend on net self-employment income and other plan-specific rules.

How to decide

No employeesStart with the Solo 401(k). Higher contribution ceiling than a SEP IRA at most income levels, Roth access, plan loan availability, and a clean path to both mega backdoor Roth contributions and backdoor Roth IRA contributions make it the stronger default for most solo operators.
No employees, want simplicityThe SEP IRA is a reasonable choice. Setup is minimal and contributions are flexible. The tradeoffs are no catch-up contributions, limited Roth access, and the pro-rata rule, which can complicate backdoor Roth IRA contributions if you carry a SEP IRA balance.
Have employeesThe SIMPLE IRA is the lowest-cost way to offer a retirement benefit to staff. If you also want to maximize your own contributions and maintain clean backdoor Roth IRA access, a Safe Harbor 401(k) is worth the additional administrative cost.
High income, older, want to maximizeA defined benefit plan, either alone or combined with a Solo 401(k), can allow substantially higher contributions than any other option. Requires actuarial work and consistent funding, but the tax deduction can be significant.

Frequently asked questions

What is the best retirement plan for a self-employed person in 2026?

For most self-employed individuals with no employees, the Solo 401(k) is the strongest option. It allows up to $72,000 in total contributions in 2026 ($80,000 if age 50 or older), includes a Roth option, and permits plan loans. At lower income levels, a SEP IRA is simpler and still allows meaningful contributions.

How much can I contribute to a Solo 401(k) in 2026?

Up to $72,000 if you are under 50, combining the $24,500 employee deferral with employer profit-sharing of up to 25% of net self-employment earnings. If you are age 50 or older, the total is $80,000. Under SECURE 2.0, individuals aged 60 to 63 can contribute up to $83,250.

How much can I contribute to a SEP IRA in 2026?

Up to $72,000 or 25% of compensation, whichever is less. For self-employed individuals, the effective rate is approximately 20% of net self-employment income due to the self-employment tax deduction. There are no catch-up contributions for SEP IRAs.

What is the SIMPLE IRA contribution limit for 2026?

Employees can contribute up to $17,000, with a $4,000 catch-up for those age 50 or older. Under SECURE 2.0, individuals aged 60 to 63 can contribute up to $22,250. Employers must match either up to 3% of pay or provide a 2% nonelective contribution for all eligible employees.

Can a small business owner contribute to both a Solo 401(k) and a SEP IRA?

Generally not at the same time for the same business, as contribution limits apply across plans. The rules depend on how the SEP IRA was set up. If you have a W-2 job and self-employment income, different rules may apply. Consult a financial planner or tax advisor before combining plans.

What is a Safe Harbor 401(k) and when does it make sense?

A Safe Harbor 401(k) bypasses IRS nondiscrimination testing by requiring mandatory employer contributions. It is useful when the business owner or highly compensated employees want to maximize their own contributions without the plan failing testing due to low participation from other employees. The employer must contribute either a matching contribution or a 3% nonelective contribution for all eligible employees.

What is a defined benefit plan and who should consider one?

A defined benefit plan allows contributions determined actuarially based on the benefit you want to receive at retirement, your age, and your income. For high-income business owners in their 50s or 60s, this can allow contributions well above $100,000 per year. These plans require annual actuarial work and consistent funding, but the tax deduction can be substantial for the right situation.

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This article is for educational and informational purposes only and does not constitute personalized investment, tax, or financial planning advice. Contribution limits and plan rules are based on 2026 IRS guidance and are subject to change. Individual contribution amounts depend on net self-employment income, compensation, and other plan-specific rules. Consult a qualified financial planner or tax professional before establishing or contributing to any retirement plan. Advisory services are offered through Core Planning LLC, a Registered Investment Advisor. For additional disclosures please visit corepln.com/disclosures.

Max Novak