What Is the Best Retirement Plan for a Business Owner Making Over $500K?

If you are a business owner earning more than $500,000 per year, your retirement plan is probably your single largest untapped tax deduction. Most CPAs default to a basic SEP IRA or a standard 401(k) and call it a day. But those plans cap your contributions far below what you could be sheltering from taxes. The difference between the right plan and the wrong one can be $100,000 or more in annual tax savings.

This guide breaks down the retirement plan options available to high-income business owners, compares the contribution limits and tax benefits of each, and explains how to stack multiple plans together to create a tax-sheltering strategy that matches your income level.

Why Standard Retirement Plans Fall Short at $500K+

The most common retirement plan for self-employed professionals and small business owners is the SEP IRA. It allows contributions of up to 25% of net self-employment income, capped at $70,000 for 2026. That sounds generous until you realize that on $750,000 of income, you are still paying federal taxes at 37% on over $680,000 of taxable income after your SEP contribution.

For a physician, attorney, or consultant earning $500,000 to $1,500,000 annually, a $70,000 deduction barely moves the needle. You need a plan structure that allows $150,000, $250,000, or even $350,000+ in annual tax-deductible contributions. Those plans exist, are fully IRS-compliant, and are used by sophisticated business owners across the country. They just require proper design and implementation.

Option 1: The Solo 401(k) - The Starting Point

A Solo 401(k), also called an Individual 401(k), is available to business owners with no full-time W-2 employees other than a spouse. Under IRC Section 401(a), you can contribute as both the employee and the employer.

For 2026, the limits break down as follows. As the employee, you can defer up to $23,500 (or $31,000 if you are 50 or older, thanks to the catch-up provision under IRC Section 414(v)). As the employer, you can contribute up to 25% of your W-2 compensation from the business or 20% of net self-employment income for sole proprietors. The combined employee-plus-employer total caps at $70,000, or $77,500 with catch-up contributions.

If both you and your spouse work in the business, you can each make the full contribution, pushing total household deferrals to $140,000 or more per year. That is a meaningful deduction, but for business owners earning $750K+ who want to shelter more aggressively, it is still not enough.

Option 2: The Cash Balance Plan - The High-Income Workhorse

A Cash Balance plan is a type of defined benefit plan structured under IRC Section 401(a) that allows dramatically higher contributions than any defined contribution plan. Unlike a traditional pension that promises a monthly payment, a Cash Balance plan defines your benefit as an account balance that grows by a guaranteed pay credit and an interest credit each year.

The contribution limits are based on actuarial calculations, factoring in your age, target retirement age, and projected benefit. In practice, this means a 45-year-old business owner can contribute approximately $150,000 to $200,000 per year. A 55-year-old can contribute $250,000 to $350,000+ per year. These contributions are fully tax-deductible in the year they are made.

Consider the numbers: a 50-year-old business owner earning $800,000 who contributes $200,000 to a Cash Balance plan saves approximately $74,000 in federal income tax alone in a single year (assuming the 37% marginal rate). Over ten years, that is $740,000 in tax savings, not counting state tax savings or the tax-deferred investment growth inside the plan.

Option 3: Stacking a Solo 401(k) + Cash Balance Plan

Here is where the strategy gets powerful. The IRS allows you to maintain both a defined contribution plan (your Solo 401(k)) and a defined benefit plan (your Cash Balance plan) simultaneously. When you stack them, you can contribute $70,000 to the 401(k) plus $200,000+ to the Cash Balance plan in the same year. That is $270,000 or more in total tax-deductible retirement contributions.

For a business owner in the 37% federal bracket plus a state income tax of 5-13%, the combined tax savings from this strategy can exceed $120,000 per year. The money grows tax-deferred and can be rolled into an IRA at retirement for continued tax-advantaged growth and flexible withdrawal planning.

This is not an aggressive or exotic strategy. It is a well-established approach used by tens of thousands of business owners, medical professionals, law firm partners, and consultants. The key is proper plan design and an annual actuarial certification, which a qualified third-party administrator handles.

How Entity Structure Affects Your Options

Your business entity type directly impacts which retirement plans you can use and how contributions are calculated. S-Corporation owners calculate employer contributions based on W-2 wages paid by the corporation, meaning you need to set your salary high enough to support meaningful plan contributions. For a business owner running an S-Corp, this requires careful coordination between salary, distributions, and plan contributions.

Sole proprietors and single-member LLC owners calculate contributions based on net self-employment income after deducting one-half of self-employment tax. C-Corporation owners have the most flexibility because the corporation can deduct plan contributions as a business expense while the owner-employee receives the full benefit.

If you are considering restructuring your entity to optimize retirement plan contributions, our retirement and exit strategy team can model the tax impact of different entity configurations before you make any changes.

The Defined Benefit Plan - Maximum Contribution, Maximum Complexity

A traditional Defined Benefit plan (as opposed to the Cash Balance variant) promises a specific annual payment at retirement. The IRS allows a maximum annual benefit of $280,000 at age 62 for 2026. To fund that promise, you can deduct whatever the actuary determines is necessary each year, which for older business owners (55-62) can exceed $300,000 annually.

The trade-off is commitment. Once you establish a Defined Benefit plan, you are required to make minimum annual contributions regardless of whether your business has a great year or a slow one. This makes them best suited for business owners with stable, predictable income of $500,000 or more who expect to maintain that level for at least five to seven years.

Comparing the Options Side by Side

Here is how the plans compare for a 50-year-old business owner earning $800,000:

A SEP IRA allows a maximum contribution of approximately $70,000, producing a federal tax savings of about $25,900. A Solo 401(k) allows up to $77,500 (with catch-up), saving approximately $28,675 in federal tax. A Cash Balance plan alone allows approximately $195,000, saving roughly $72,150. A Solo 401(k) stacked with a Cash Balance plan allows approximately $272,500 combined, producing federal tax savings of approximately $100,825 per year.

That is a difference of nearly $75,000 per year in federal taxes between the most basic option and the most sophisticated one. Over a decade, the gap exceeds $700,000 in tax savings alone, before considering state taxes and investment returns on the tax-deferred dollars.

What About Employees?

If your business has W-2 employees beyond yourself and your spouse, retirement plan design becomes more complex. The IRS anti-discrimination rules under IRC Sections 401(a)(4) and 410(b) require that plans not disproportionately benefit highly compensated employees. However, proper plan design using cross-testing, age-weighting, and new comparability methods can still direct the vast majority of contributions to the owner while providing modest (3-5% of compensation) contributions for staff.

A skilled plan designer can structure a Cash Balance plan so that 85-90% of total contributions go to the owner, with the remaining 10-15% covering the required employee benefits. In many cases, the cost of employee contributions is far outweighed by the owner's tax savings.

Implementation Timeline and Key Deadlines

Timing matters. A Solo 401(k) must be established by December 31 of the year you want to make contributions, though you have until your tax filing deadline (including extensions) to actually fund it. Cash Balance and Defined Benefit plans also need to be established by December 31, but ideally should be designed and set up by September or October to allow proper actuarial calculations and funding planning.

If you are reading this mid-year, you are in the ideal window to design and implement a plan that will reduce your current-year tax bill. Waiting until November or December is still possible but creates unnecessary time pressure and limits your options.

The Bottom Line

For business owners earning $500,000 or more, a basic SEP IRA or standard 401(k) is leaving six figures of tax savings on the table every single year. The combination of a Solo 401(k) and a Cash Balance plan provides the highest allowable tax-deductible contributions under the Internal Revenue Code, often exceeding $250,000 to $350,000+ per year depending on age.

The right plan structure depends on your age, income stability, entity type, number of employees, and long-term financial goals. There is no one-size-fits-all answer, which is exactly why working with a specialized tax planning firm that understands these strategies makes a measurable difference in your lifetime tax bill.

Related Tax Planning Resources

Continue exploring our tax planning insights with these related articles:

• Business Owner & Small Business Tax Services
• Retirement & Exit / M&A Tax Strategy
• Individual Tax Planning for High Earners

For personalized guidance, contact AE Tax Advisors to schedule a consultation.