For high-earning consultants who have already maxed out their solo 401(k), the next question that tends to come up is whether to add a cash balance plan on top. The potential is real. With the right setup, the combined contribution capacity can exceed $300,000 per year of tax-deferred savings. But a cash balance plan is a different animal from a 401(k), and it brings commitments that deserve a careful look before you sign up.
I recently heard from a listener with exactly this situation. They have a solo 401(k) for their consulting business, contribute the max every year, and are trying to figure out whether layering a cash balance plan on top makes sense. They also wanted to understand how the two plans interact and what the long-term commitment looks like.
Let me walk through how I think about each piece.
The Solo 401(k) Is the Easy Part
The solo 401(k) is by far the simpler of the two plans to run. You set it up through your broker, fund it every year, and because it’s a solo plan with no employees, the usual compliance complexity disappears. No nondiscrimination testing. No top-heavy testing. None of the administrative layers that come with running a plan for a team.
Your only real constraint is hitting the maximum contribution, which is based on a percentage of the business’s total earnings. That part is well understood and manageable.
A Cash Balance Plan Is a True Pension
This is where the picture changes. A cash balance plan is a defined benefit plan. It’s a true pension, in the old-school sense of the word, and it’s completely separate from your solo 401(k). That separation is actually helpful, because it means you have different contribution limits, different reporting requirements, and different responsibilities for each plan. You’re not going to have to worry too much about the plans interacting with each other.
The complexity lives inside the cash balance plan itself. Think of the old pension plans, where the company put in a certain amount each year based on employee ages and compensation, and that funding built toward a future benefit. The risk of funding that benefit sat with the employer, not the employee. That’s actually why the shift to 401(k)s happened in the first place. Employers didn’t want to carry the pension risk forever, so they moved to 401(k)s and pushed that risk over to the employee.
In a solo consulting setup, you’re both the employer and the employee. You’re taking on the employee-side risk through your 401(k) investments, and you’re also taking on the pension-side funding risk through the cash balance plan. That changes what’s required of you.
Contributions are driven by your age and a built-in assumed growth rate, not by what you feel like putting in. You’ll need to bring in an actuary, who will review the plan each year and determine whether the pension is overfunded or underfunded, the same way you hear about state pensions being overfunded or underfunded. You’ll also need a pension company to establish and administer the plan, and there are real ongoing administrative and actuarial costs along the way.
The Contribution Capacity Can Be Substantial
Despite the complexity, the numbers can be compelling. Depending on your age and income, cash balance plan contribution limits can exceed $200,000 in a given year. Combined with a fully funded solo 401(k), it’s possible to stack away roughly $300,000 annually in tax-deferred savings.
For a consultant with consistently high income, that’s a meaningful lever.
The IRS Wants Consistent Funding
Here’s where a lot of the disconnect happens. The IRS designed these plans to be actual pensions. That means they expect consistent funding across multiple years. They’re going to look at the plan and ask whether it’s truly a pension, or whether it’s really just a way to shelter a single big year of income.
That framing matters for the question you should be asking yourself. Why are you opening this conversation in the first place?
If it’s because your consulting income is high and you expect it to stay high for at least the next five years, a cash balance plan is probably worth the administrative and actuarial overhead. If it’s because you just had a really good year and you’re looking to shelter that income with a plan you shut down next year, this is not the right tool.
A cash balance plan fits best with high, stable income. If your consulting income is lumpy, you have two related issues. The first is that you risk underfunding your own pension, because you may not have the income to fund it fully in a down year. The second is that you lose some flexibility that you otherwise have with the solo 401(k) alone.
The Exit Strategy Opens Tax Planning Doors
One of the more attractive features of a cash balance plan, when it’s set up correctly and funded consistently for several years, is the exit. Once the plan has done its job, you can shut it down and the balance rolls into your IRA.
From there, you open up possibilities like Roth conversions and other tax planning moves down the road. That’s typically the full picture I see with clients who make this work well. Stack as much cash now, tax-deferred, with a plan to convert at a lower tax rate later.
It Comes Down to Income Profile
Running a solo 401(k) and a cash balance plan side by side is absolutely workable, and for the right consulting practice it can shelter far more income than the 401(k) alone. There’s no conflict between the two plans.
The real questions aren’t mechanical. They come down to your income profile. Is this income going to stay high and stable for the foreseeable future? Are you prepared to fund the pension consistently, pay for the actuary and administrator, and treat this like the pension it is?
If the answer is yes, the payoff can be significant. If you’re hoping for a one-year tax shelter, look elsewhere. The IRS designed this plan for people who are in it for the long haul.
This post is adapted from a recent episode of the Scholar Wealth Podcast. For more perspective on cash balance plans and retirement savings for consultants, listen to the full podcast episode here.