Many self-employed professionals want to save more for retirement, but they do not have access to a traditional employer-sponsored plan. A standard IRA may help, but the contribution limits may not be enough for business owners who want to save more aggressively.

Who Qualifies for a Solo 401(k)?

A Solo 401(k), also called a one-participant 401(k), is built for a business owner with no employees other than a spouse. The IRS says these plans follow the same rules as other 401(k) plans, so if you have ever had a workplace 401(k), the mechanics will look familiar. The difference is that you wear both hats: employee and employer.

Why the “Two Hats” Matter

The two-hat structure is what makes a Solo 401(k) flexible. As the employee, the business owner may make salary deferral contributions. As the employer, the business may also make profit-sharing contributions. This can allow higher total contributions than some other retirement options, especially when income is strong enough to support both contribution layers.

A Solo 401(k) is generally for self-employed people or business owners with no full-time employees other than a spouse. This may include sole proprietors, independent contractors, consultants, and small business owners.

You may be a fit if:

  • You have self-employment income
  • You have no full-time employees other than a spouse
  • Your spouse, if involved, draws income from the business

Worth reviewing eligibility before you set anything up, since hiring or changing your business structure can affect whether the plan still fits. And if you are weighing this against simply funding an IRA, the gap in contribution room is usually what settles it.

How Solo 401(k) Contributions Work

Solo 401(k) contributions have two main parts: the employee deferral and the employer profit-sharing contribution. Understanding both matters because the combined structure is what can make the plan valuable.

Employee Deferral

For 2026, the elective deferral limit is $24,500, up from $23,500 in 2025. If you are 50 or older, the catch-up adds $8,000 on top, bringing you to $32,500. Between 60 and 63, the catch-up is larger still, at $11,250, which puts the deferral ceiling at $35,750 for those four years. That window is worth planning around rather than discovering after the fact.

Employer Profit-Sharing Contribution

The employer contribution sits on top of your deferral, and it is where the plan pulls away from an IRA. It runs up to 25 percent of compensation. If you are a sole proprietor rather than an S-corp paying yourself W-2 wages, the effective figure lands closer to 20 percent of net self-employment income, because the calculation backs out half your self-employment tax and the contribution itself.

This is where professional review matters. A contribution that looks simple at first can change once income, deductions, payroll structure, and tax planning are considered.

Solo 401(k) vs. SEP IRA: What Changes?

A SEP IRA is another retirement savings option for self-employed professionals and business owners. Both can be useful, but they work differently.

Feature Solo 401(k)                            SEP IRA
Best for Self-employed owners with no full-time employees except a spouse Self-employed owners and small businesses
Contribution type Employee deferral plus employer contribution Employer contribution only
Roth option               May be available if the plan allows Generally not available in a standard SEP IRA
Catch-up contributions                 May be available for eligible participants Not available as an employee catch-up
Flexibility Often more flexible at lower income levels Often simpler to administer 

Neither option is automatically better. The right fit depends on income, employees, savings goals, administrative preferences, and tax planning needs.

When a Solo 401(k) Can Become a Powerful Tax Tool

A Solo 401(k) is most useful when you want to shelter more than an IRA permits. Pre-tax contributions reduce current taxable income. Roth contributions give up that deduction in exchange for tax-free growth, and where your plan allows both, the split becomes a planning decision rather than a default. One change worth knowing: as of 2026, catch-up contributions must be made as a Roth for higher earners.

A Solo 401(k) may become especially useful when:

  • You have strong self-employment income
  • You want to contribute more than an IRA allows
  • You want both employee and employer contribution flexibility
  • Your spouse works in the business and can contribute
  • You want pre-tax and potentially Roth planning options
  • You want retirement savings to coordinate with broader tax planning

Tax treatment depends on plan design, income, contribution type, and current tax rules. The value comes from using the plan intentionally, not simply opening it.

What to Review Before Opening a Solo 401(k)

A Solo 401(k) should fit your business structure, income, savings goals, and long-term retirement plan. The contribution potential can be attractive, but setup and administration still need attention.

Before setting up a plan, review:

  • Whether you have an eligible self-employment income
  • Whether you have any employees who affect eligibility
  • How much you can realistically contribute
  • Whether Roth contributions are available
  • Whether loans or advanced strategies are allowed
  • Plan setup deadlines and administrative responsibilities
  • How the plan fits your retirement and tax strategy

The plan should be selected because it fits your situation, not just because it has a high contribution limit.

Build a Self-Employed Retirement Plan With the Right Structure

A Solo 401(k) can be a strong tool for the right self-employed professional, but the value depends on eligibility, contribution capacity, tax goals, and plan design. It should fit your cash flow, business income, and retirement timeline. Contact Berger Financial Group today to review whether a Solo 401(k), SEP IRA, or another retirement planning strategy fits your business income and long-term goals.