Go beyond a basic 401(k)

Go beyond a basic 401(k)

Give your employees more than just a 401(k), join the movement.

5 min read

Solo 401(k): The Ultimate Guide to Secure Your Retirement

David Ramirez, CFA
December 19, 2023
Solo 401(k): The Ultimate Guide to Secure Your Retirement
Table of contents

Key Takeaways:

  • Solo 401(k)s are designed for self-employed individuals without full-time employees.
  • They allow you to save up to $66,000 (or $73,500 age 50+) pre-tax or Roth.
  • They can provide greater investment flexibility, including realestate or cryptocurrency.
  • They can provide significant taxx breaks in good years and fleibility to ride business downturns

Retirement planning has many options, but the Solo 401(k) stands out for self-employed individuals. Often overlooked, this retirement plan offers benefits tailored to solo entrepreneurs and freelancers. This guide explains the Solo 401(k) retirement plan, its benefits, complexities, and importance for your retirement.

Solo 401(k) Explained

What is a Solo 401(k)?

A Solo 401(k) is a retirement plan for self-employed people or business owners without full-time employees. This retirement plan has various names (Solo-k, individual 401(k), or i401(k)), but they share the same benefits. This plan lets you contribute as an employee and an employer, maximizing retirement savings and getting tax benefits.

How does it differ from traditional 401(k) plans?

The Solo 401(k) is simpler than traditional 401(k) plans for larger businesses with multiple employees. It offers the same benefits but without the complexities of ERISA compliance, which governs regular 401(k) plans. This means fewer administrative burdens and more flexibility for the account holder.

Eligibility and Setting Up

Who can open a Solo 401(k)?

Solo 401k's are designed for business owners with no employees.  It's a good choice for freelancers, consultants, solo entrepreneurs, or business owners without full-time employees, except their spouses. Importantly, part-time employees working less than 1,000 hours a year or employees under age 21, don't count against this rule.

Steps to set up your Solo 401(k)

Setting up a Solo 401(k) is simple, but following each step carefully is essential to get all the benefits.

Step 1: Choose a Plan Provider:

Select a financial institution or brokerage offering Solo 401(k) plans. Some popular choices include ForUsAll, Fidelity, Vanguard, and Charles Schwab. Each provider may offer different investment options and fee structures, so comparing before committing is wise.

Step 2: Fill Out the Necessary Paperwork:

Once you've chosen a provider, you must complete the documentation to establish the plan. This typically includes a plan adoption agreement and an account application.  You'll need your employer identification number (EIN), so have it handy!

Step 3: Set Up Contribution Amounts:

Decide how much you want to contribute as both the employer and the employee. Remember, the Solo 401(k) allows for generous contribution limits, so plan wisely to maximize your tax benefits.

Step 4: Stay Compliant:

Ensure you know any annual reporting requirements, especially if your Solo 401(k) assets exceed $250,000. In such cases, you must file Form 5500 with the IRS.

Contribution Limits and Benefits

2023 SoloK Contribution Limits

The Solo 401(k) boasts one of the highest IRS contribution limits. You can contribute $22,500 as an employee or $30,000 if you're 50 or older, thanks to 50+ catch-up contributions.

You can contribute a maximum of 25% of your self-employment earnings. However, the total amount should be at most $66,000. If you are eligible for catch-up contributions, the limit increases to $73,500.

Employee Contribution Options

Solo 401(k)s allow you to contribute before or after taxes at the ordinary 401 k contribution limits. This provides tax benefits now or tax-free growth in the future.  

Traditional pre-tax contributions: Lower Taxes Today

A Solo 401(k) allows you to save pre-tax earnings into your 401(k), reducing your taxable income today.  Once in your 401(k) your savings will grow tax-deferred, meaning you’ll need to pay ordinary income taxes when you take the money out at retirement.    This option provides:

  1. Tax-Deferred Growth: Your investments grow tax-free until you start making withdrawals during retirement.
  2. Tax deductions: Your contributions reduce your taxable income, lowering your income taxes.

Roth 401(k) Contributions: Tax-Free Growth

On the other hand, Roth 401(k) contributions allow you to defer money after you pay income taxes.  This choice will not reduce your taxes immediately. However, your savings will continue to grow tax-free forever. This is as long as you do not withdraw money within five years of your initial Roth contribution.

Unlike Roth IRAs, Solo 401(k)s do not have income caps. This means that there are no limits on how much you can contribute.

Employer Contribution Options

Solo 401(k)s allow entrepreneurs to make additional employer contributions up to 25% of compensation into their account on a pre-tax basis.  For example, assume Sarah, age 52, earned $250,000 in W-2 wages from her S-Corp in 2023.  Sarah could contribute:

  • Employee contributions: $22,500
  • 50+ Catchup contributions: $7,500
  • Employer contributions: $43,500
  • Total 401(k) Savings: $73,500

To find the highest employer contribution, subtract 50% of your self-employment tax and personal contributions from your earnings.

Tax Benefits of Solo 401(k)

The Solo 401(k) gives tax advantages: lower taxes now (pre-tax savings) or tax-free growth (Roth contributions). By making pre-tax contributions, You can lower your tax income by up to $73,500.

This could save you $22,000 in taxes today (assuming a 30% tax rate).  If you withdraw money for retirement, you may have to pay taxes. However, if you are in a lower tax bracket, you'll likely reduce the total amount you pay in taxes.

With Roth contributions, you won’t lower your taxable income today. However, your Roth contributions will grow tax-free forever.  This can be an excellent option for people earlier in their career or who want to lock in their tax rate today.      

Investment Options

More Investment Choice

With the right provider, you can explore investments beyond traditional options such as stocks, bonds, or mutual funds. Options may include precious metals, cryptocurrency, and even private businesses.

Real Estate and Solo 401(k)

One of the standout features of some Solo 401(k) plans is the ability to invest in real estate. You can buy the property, and any rental income will return to your 401(k) tax-deferred.  However, this option can be complicated, and there are significant restrictions on your personal use of the property.

Withdrawals and Loans

Rules for Withdrawals

If you withdraw your money before you turn 59.5, you may be subject to a 10% penalty. In addition, you may also have to pay income taxes. These penalties and taxes are similar to those imposed on 401(k)s or IRAs. However, there are two ways to avoid paying these penalties and taxes: A hardship withdrawal or a Solo 401(k) Loan.

Taking a Loan from Your Solo 401(k)

Some Solo 401(k) plans allow you to borrow funds from your account. You can borrow a limited amount, either 50% of your account balance or $50,000, whichever is less. Like a regular loan, you must repay the loan with interest (typically over a 1-5 year term). However, since you make the loan to yourself, your 401(k) receives the interest.

Rollovers and Transfers

Rolling Over Other Retirement Accounts

You can roll old 401(k)s from previous employers and even some IRAs into your Solo 401(k). This consolidation can simplify your financial landscape and potentially offer better investment options.

Transferring Your Solo 401(k)

Life is uncertain, and there may be a point when you choose to shut down your business or hire permanent staff. In such cases, you can transfer your Solo 401(k) funds to another retirement account without tax implications.

Potential Pitfalls

Common Mistakes to Avoid

While the Solo 401(k) is a powerful tool, it's not immune to mistakes:

  1. Over-contributing: Ensure you stay within the annual contribution limits.
  2. Ignoring administrative tasks: While the Solo 401(k) has less paperwork, staying updated on reporting needs is essential.  Once your balance exceeds $250k, you may need to file an annual form 5500.

How to Rectify an Error

People make mistakes, but they can often rectify them. If you make a mistake with your Solo 401(k), like contributing too much, it's essential to fix it quickly. Reach out to your plan provider for guidance on correcting the mistake.

Solo 401(k) vs. Other Retirement Plans

Comparing with SEP IRA and SIMPLE IRA

While the Solo 401(k) is an excellent option for many self-employed individuals, it's not the only choice. The SEP-IRA and SIMPLE IRA are also popular choices. Compare advantages and limitations to find the best fit for your needs.

Which One is Right for You?

Your retirement plan choice depends on various factors, including income level, business structure, and retirement goals. It's always a good idea to consult with a financial advisor to make an informed decision.


How often can I change my Solo 401(k) contributions?

  • You can change your contributions whenever you want. However, you must be cautious about exceeding the yearly limit of $22,500 in 2023 ($30,000 for those age 50+).

Can my spouse contribute to my Solo 401(k)?

  • If your spouse earns money from your business, they can also contribute to the Solo 401(k). This will double the contribution limits.

What happens to my Solo 401(k) if I hire employees?

  • If you hire full-time workers, you must switch your Solo 401(k) to a regular 401(k) plan. This regular plan comes with additional administrative tasks. However, you can still hire part-time employees or employees under age 21.

Are there any fees associated with a Solo 401(k)?

  • Fees can vary based on the plan provider. Some might charge a flat annual fee, while others might have a fee structure based on the assets under management.

When is the deadline to set up a Solo 401(k)?

  • You usually have until December 31st to set up a Solo 401(k) and contribute for that tax year.

Can I roll over my Solo 401(k) into an IRA?

  • You can transfer your Solo 401(k) funds to an IRA or another employer's 401(k) without any tax payments.

Are Solo 401(k)s subject to required minimum distributions (RMDs)?

  • Yes, once you reach age 73, the IRS will require that you start taking distributions. However, starting in 2024, the requirement to take Roth distributions will no longer be necessary.


The Solo 401(k) is a hidden gem in the world of retirement planning for the self-employed. A powerful tool for business owners without employees, it offers high contribution limits, flexible investments, and tax breaks. As with any financial decision, research, understand the nuances, and consult with professionals if needed.

The Solo 401(k) can be the foundation of your retirement plan. It ensures a bright and secure future with the right approach.

Go beyond a basic 401(k)
Give your employees more than just a 401(k), join the movement.
Author profile pic
About Author -
David Ramirez, CFA

David Ramirez, CFA, is a recognized 401(k) expert with over 20 years of experience in 401(k), ERISA, cash balance plans, and ESOPs. A UC Berkeley graduate, he played a pivotal role at Financial Engines, a 401(k) advisory firm founded by Nobel Laureate William Sharpe, Ph.D., where he was a portfolio manager who helped manage over $50B in 401(k) assets.  His clients included some of the largest Fortune 500 companies and state governments.

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This material has been prepared for informational and educational purposes only and should not be construed as a recommendation by ForUsAll, Inc., its affiliates or employees (collectively, “ForUsAll”)  to activate a cryptocurrency window or invest in crypto.  Investing in crypto can be risky and investors must be able to afford to lose their entire investment.  You should consult with your own advisers before activating a cryptocurrency window or investing in crypto.  ForUsAll does not provide legal, tax, or accounting advice. Please refer to your Plan's fee disclosure for more details.© 2023 ForUsAll, Inc. All rights reserved.
1 Schwab 2022 401(k) Participant Study - Gen Z/Millenial Focus, October 2022.
2 As of 12/31/2022. Employees include both current employees and terminated participants with a balance.
3 "Morgan Stanley At Work: The Value of a Financial Advisor" Morgan Stanley, March 2022.
4 Sarah Britton was a client when she provided this testimonial through an independent third party review website. She received no compensation for her remarks. There are no known conflicts of interest in the provision of her comments related to the services provided.