Understanding Solo 401k Plans at Charles Schwab

What Is a Solo 401(k) Plan and How Does It Work at Charles Schwab

A Solo 401(k), also called an individual 401(k) or self-employed 401(k), is a retirement savings plan designed for self-employed people and business owners with no employees (except a spouse). Unlike a traditional IRA, which has annual contribution limits of $7,000 (or $8,000 if you're age 50 or older as of 2024), a Solo 401(k) allows much higher annual contributions—up to $69,000 in 2024, or $76,500 if you're age 50 or older. This significant difference makes Solo 401(k) plans attractive to people who want to save more for retirement.

Charles Schwab offers Solo 401(k) plans through its self-directed brokerage platform. When you open a Solo 401(k) at Schwab, you control the investment choices within the plan. This means you can invest in stocks, bonds, mutual funds, exchange-traded funds (ETFs), and other securities available through Schwab's platform. The account operates under IRS rules, which means contributions may reduce your current taxable income, and investment growth inside the account is tax-deferred until you withdraw funds in retirement.

The structure of a Solo 401(k) includes two parts: employee deferrals and employer contributions. As the employee, you can contribute up to 100% of your compensation (with a $23,500 limit in 2024, or $29,000 if age 50 or older). As the employer, you can contribute an additional amount, up to 25% of your net self-employment income. This dual contribution structure is one reason Solo 401(k) plans allow such high annual savings.

Schwab's Solo 401(k) offering includes online account management tools, educational resources, and administrative support. The platform allows you to monitor your investments, make trades, and view performance in real time. Schwab does not charge annual custodian fees for Solo 401(k) accounts, which reduces the ongoing costs of maintaining the plan compared to some other providers.

Practical Takeaway: A Solo 401(k) at Schwab works well if you're self-employed with significant income and want to save substantially for retirement. Research whether the investment options and tools align with your investment strategy before opening an account.

Contribution Limits and How They Calculate for 2024

Understanding contribution limits is essential because these numbers determine how much you can add to your Solo 401(k) each year. The IRS sets these limits, and they change annually. For 2024, the employee deferral limit is $23,500, which applies to wages or compensation you pay yourself. If you're age 50 or older, you can make an additional "catch-up" contribution of $7,500, bringing your total employee deferral to $30,000.

The employer contribution portion has a different calculation. As your own employer, you can contribute up to 25% of your net self-employment income. To calculate this, you start with your business profit, subtract half of your self-employment tax, and then multiply by 0.25. This percentage-based contribution is separate from your employee deferral and allows the plan to accumulate funds more quickly. For someone earning $100,000 in net self-employment income, the employer contribution could be approximately $19,000 to $20,000 (accounting for self-employment tax adjustments).

The combined total of both employee and employer contributions cannot exceed $69,000 in 2024 ($76,500 if age 50 or older). This aggregate limit prevents anyone from contributing more than the annual maximum, regardless of how they split the contributions between employee and employer portions. If you have a spouse who is also self-employed, each spouse can maintain a separate Solo 401(k) with separate contribution limits, potentially allowing household contributions to double.

At Charles Schwab, the platform provides calculation tools and resources to help you determine your contribution limits based on your income. The IRS Form 1040 Schedule C (for sole proprietors) or Schedule K-1 (for pass-through entities) will show your net self-employment income, which is the figure you use to calculate both portions of your contribution. Schwab's educational materials walk through these calculations step by step.

It's important to note that these contribution limits apply per calendar year. You must complete all contributions by December 31 to count them toward that year's limit. However, employer contributions can be made as late as your tax filing deadline (including extensions), which may be April 15 or later of the following year.

Practical Takeaway: Use your most recent business tax return to estimate your contribution capacity. If your income varies year to year, plan conservatively in lower-income years and adjust in higher-income years. Track your contributions throughout the year to avoid exceeding limits.

Tax Advantages and How They Impact Your Bottom Line

Solo 401(k) plans offer significant tax advantages that can reduce your current tax burden while growing retirement savings. The primary advantage is the tax deduction for contributions. Employee deferrals and employer contributions are both tax-deductible, meaning they reduce your adjusted gross income (AGI) on your tax return. If you contribute $50,000 to your Solo 401(k) in a given year and earn $120,000 in net self-employment income, your taxable income is reduced to $70,000 for federal income tax purposes.

The tax-deferred growth inside the account is another major benefit. Unlike a taxable brokerage account where you pay annual taxes on dividends and capital gains, a Solo 401(k) allows all investment growth—stock appreciation, dividend income, and interest—to compound without triggering annual tax bills. This tax deferral can significantly increase your account balance over decades. For example, a $50,000 initial investment growing at an average rate of 7% per year would grow to approximately $386,000 after 30 years without annual tax drag, compared to less after taxes in a regular account.

There are two types of Solo 401(k) plans available at Charles Schwab: traditional and Roth. A traditional Solo 401(k) provides an immediate tax deduction in the year you make the contribution, but you pay income tax on withdrawals in retirement. A Roth Solo 401(k) does not provide a current tax deduction, but qualified withdrawals in retirement are completely tax-free. The choice between these depends on whether you believe your tax rate will be higher or lower in retirement.

Solo 401(k) plans also offer loan provisions that IRAs do not. You can borrow up to 50% of your account balance (with a maximum of $50,000) and repay the loan with interest over a set period. This feature provides emergency access to funds without triggering early withdrawal penalties, though it does reduce the assets growing tax-deferred inside the plan.

One tax consideration to keep in mind: Solo 401(k) contributions reduce your net self-employment income used to calculate self-employment tax. However, you cannot reduce your self-employment tax calculation below a certain threshold. Schwab's resources explain how self-employment tax interacts with Solo 401(k) contributions, which is important when planning your annual contributions.

Practical Takeaway: Calculate your estimated tax savings from Solo 401(k) contributions. If you're in a 24% federal tax bracket and contribute $30,000, you save approximately $7,200 in federal taxes that year. This tax savings can be reinvested or used to cover other business expenses.

Setting Up Your Solo 401(k) at Charles Schwab: Step-by-Step Process

Opening a Solo 401(k) at Charles Schwab involves several steps, starting with determining whether a Solo 401(k) structure suits your business situation. You must be self-employed with no employees (except a spouse) to maintain a Solo 401(k). If you have employees beyond your spouse, you'll need a different retirement plan structure. Charles Schwab's website includes a questionnaire that describes various retirement plan options so you can understand which plan type matches your business.

Once you determine that a Solo 401(k) is appropriate, you'll need to set up the plan document. A plan document is a legal agreement that establishes the rules of your retirement plan. Charles Schwab provides pre-written plan documents that comply with I