As 2018 comes to an end, it is critical that Solo 401(k) owners understand when and how to make their 2018 contributions. There are three important deadlines you must know if you have a Solo 401(k) or if you plan to set one up still in 2018. A Solo 401(k) is a retirement plan for small business owners or self-employed persons who have no other full time employees other than owners and spouses. It’s a great plan that can be self-directed into real estate, LLCs, or other alternative investments, and allows the owner/participants to contribute up to $55,000 per year (far faster than any IRA).

New Solo 401(k) Set-Up Deadline is 12/31/18

First, in order to make 2018 contributions, the Solo 401(k) must be adopted by your business by December 31st, 2018. If you haven’t already adopted a Solo 401(k) plan, you should start now so that documents can be completed and filed in time. If the 401(k) is established on January 1st, 2019 or later, you cannot make 2018 contributions.

2018 Contributions Can Be Made in 2019

Both employee and employer contributions can be made up until the company’s tax return deadline including extensions. If you have a sole proprietorship (e.g. single member LLC or schedule C income) or C-Corporation, then the company tax return deadline is April 15th, 2018. If you have an S-Corporation or partnership LLC, the deadline for 2018 contributions is March 15th, 2019. Both of these deadlines (March 15th and April 15th) to make 2018 contributions may be extended another six months by filing an extension. This a huge benefit for those that want to make 2018 contributions, but won’t have funds until later in the year to do so.

W-2’s Force You to Plan Now

While employee and employer contributions may be extended until the company tax return deadline, you will typically need to file a W-2 for your wages (e.g. an S-Corporation) by January 31st, 2019. The W-2 will include your wage income and any deduction for employee retirement plan contributions will be reduced on the W-2 in box 12. As a result, you should make your employee contributions (up to $18,500 for 2018) by January 31st, 2019 or you should at least determine the amount you plan to contribute so that you can file an accurate W-2 by January 31st, 2019. If you don’t have all or a portion of the funds you plan to contribute available by the time your W-2 is due, you can set the amount you plan to contribute to the 401(k) as an employee contribution, and will then need to make said contribution by the tax return deadline (including extensions).

Example

Now let’s bring this all together and take an example to outline how this may work. Sally is 44 years old and has an S-Corporation as an online business. She is the only owner and only employee, and had a Solo 401(k) established in 2018. She has $120,000 in net income for the year and will have taken $50,000 of that in wage income that will go on her W-2 for the year. That will leave $70,000 of profit that is taxable to her and that will come through to her personally via a K-1 from the business. Sally has not yet made any 2018 401(k) contributions, but plans to do so in order to reduce her taxable income for the year and to build a nest egg for retirement. If she decided to max-out her 2018 Solo 401(k) contributions, it would look like this:

1. Employee Contributions – The 2018 maximum employee contribution is $18,500. This is dollar for dollar on wages so you can contribute $18,500 as long as you have made $18,500. Since Sally has $50,000 in wages from her S-Corp, she can easily make an $18,500 employee contribution. Let’s say that Sally doesn’t have the $18,500 to contribute, but will have it available by the tax return deadline (including extensions). What Sally will need to do is let her accountant or payroll company know what she plans to contribute as an employee contribution so that they can properly report the contributions on her payroll and W-2 reporting. By making an $18,500 employee contribution, Sally has reduced her taxable income on her W-2 from $50,000 to $31,500. At even a 20% tax bracket for federal taxes and a 5% tax bracket for state taxes that comes to a tax savings of $4,625.

2. Employer Contributions – The 2018 maximum employer contribution is 25% of wage compensation. For Sally: Up to a maximum employer contribution of $36,500. Since Sally has taken a W-2 wage of $50,000, the company may make an employer contribution of $12,500 (25% of $50,000). This contribution is an expense to the company and is included as an employee benefit expense on the S-Corporation’s tax return (form 1120S). In the stated example, Sally would’ve had $70,000 in net profit/income from the company before making the Solo 401(k) contribution. After making the employer matching contribution of $12,500 in this example, Sally would then only receive a K-1 and net income/profit from the S-Corporation of $57,500. Again, if she were in a 20% federal and a 5% state tax bracket, that would create a tax savings of $3,125. This employer contribution would need to be made by March 15th, 2019 (the company return deadline) or by September 15th, 2019 if the company were to file an extension.

In the end, Sally would have contributed and saved $31,000 for retirement ($18,500 employee contribution, $12,500 employer contribution). And she would have saved approximately $7,750 in federal and state taxes. That’s a win-win.

Keep in mind, you need to start making plans now and you want to begin coordinating with your accountant or payroll company as your yearly wage information on your W-2 (self employment income for sole props) is critical in determining what you can contribute to your Solo 401(k). Also, make certain you have the plan set-up in 2018 if you plan to make 2018 contributions. While IRAs can be established until April 15th, 2019 for 2018 contributions, a Solo K must be established by December 31st, 2018. Don’t get the two confused, and make sure you’ve got a plan for your specific business.

Note: If you’ve got a single member LLC taxed as a sole proprietorship, or just an old-fashioned sole prop, or even or an LLC taxed as a partnership (where you don’t have a W-2), then please refer to our prior article here on how to calculate your Solo K contributions as they differ slightly from the s-corp example above.