What Retirement Planning for Business Owners Saves the Most Tax?

 

The Short Answer

Which plan saves the most? For a true solo, a solo 401(k). For a business with staff, a 401(k) paired with cross-tested profit sharing. For owners over roughly fifty who are older and better paid than their employees, a cash balance plan layered on top of that 401(k) beats everything else by a wide margin. Retirement planning for business owners is really a math problem about your payroll, and the answer changes when your census changes.

We run an environmental and geotechnical engineering consultancy. Two partners, ages fifty-six and fifty-two, nine employees, and eleven years of using the wrong plan.

Eleven Years With a SEP

We opened a SEP because it was easy. No testing, no administrator, one form, done in an afternoon.

It worked beautifully when there were two of us and a laptop.

Then we hired. And hired again. Nobody explained the part that mattered: a SEP requires the same contribution percentage for every eligible employee. So the year we wanted to put twenty-five percent away for ourselves, we owed twenty-five percent for nine other people.

We contributed less instead. For over a decade we throttled our own retirement to control a cost nobody had warned us about. That is what poor retirement planning for business owners looks like in practice. Quiet, expensive, invisible.

The Question That Decides Retirement Planning for Business Owners

Every article on this topic asks how much you earn. That is the wrong first question.

The right one: how old are you compared to your employees, and how much do you make compared to them?

Retirement planning for business owners works on projected benefits, not just current dollars. A fifty-six year old has fewer years until retirement, so funding a given benefit requires far larger annual contributions. The rules permit that. It is not a loophole, it is arithmetic.

Two owners in their fifties with a payroll averaging thirty-two years old is close to the ideal case. Two owners the same age as their staff is a much flatter picture.

The Ladder, Simplest to Heaviest

SEP-IRA

Easy, cheap, flexible. Contribution is a percentage of compensation, capped, and identical for everyone eligible.

Fine with no employees. Punishing them.

Solo 401(k)

Only available if the business has no full-time employees besides owners and spouses. Because it combines an employee deferral with an employer contribution, it reaches the ceiling at a much lower income than a SEP does.

If you are solo and using a SEP, run both numbers this week.

401(k) With Cross-Tested Profit Sharing

This is where most businesses with staff should live. Cross-testing evaluates the plan on projected benefits rather than raw contributions, which lets the profit share tilt toward older participants.

There is a floor. Non-owner employees generally have to receive a minimum contribution for the design to pass. That floor is the cost of admission, and it is usually far less than what a SEP would have demanded.

Cash Balance Plan

The heavyweight, layered on top of the 401(k). Contributions are actuarially determined and age weighted, so a fifty-six year old can fund dramatically more than a thirty-five year old.

For us, this single change moved several times what everything else combined had.

What It Actually Costs

We want to be straight about this, because the pitch usually is not.

• You commit to funding the plan, including in years you would rather not

• Employee contributions are real money leaving the business, every year

• An actuary and a third party administrator are required, and they are not cheap

• The money is locked up, which matters if your business ever needs it

• The deduction is a deferral, not forgiveness. You are betting on your future rate

We ran three bad quarters in 2024 and had to fund anyway. We knew going in. It still stung.

What Tax Maverick Changed

Our payroll company sold us the SEP. Nobody at that company was designing anything, and to be fair, nobody was being paid to.

Tax Maverick ran our actual census against four designs and showed the after tax result of each. The cross-tested design alone would have been worth having eight years earlier. The cash balance layer was worth more than our best year of retained earnings.

Real retirement planning for business owners starts with a census file, not a brochure.

Want Retirement Planning for Business Owners That Fits Your Payroll?

Most owners inherit whatever plan their payroll provider happened to sell them, then never revisit it as the business grows. That gap costs more every year it goes unexamined.

Contact Tax Maverick to model your plan designs against your real employee census before the year closes, or browse their product collection to see how their plan design tools, contribution modeling resources, and advisory support fit a business your size. Ask about cross-tested profit sharing, cash balance layering, and owner contribution analysis.

Frequently Asked Questions

Which plan genuinely saves the most tax? For owners over fifty with a younger, lower paid staff, a cash balance plan layered on a 401(k). For everyone else with employees, a cross-tested 401(k) profit sharing design. Retirement planning for business owners has no universal answer, so model it against your own census rather than trusting a general one.

Can we do this if we have employees? Yes, and it usually still works. You will owe employees a minimum contribution, but the design lets the owner share be far larger than a SEP would allow.

Is a cash balance plan worth the administration? For us, easily. The threshold is roughly whether the owner contribution meaningfully exceeds the combined employee and administrative cost. An actuary can tell you in a week.

What happens in a bad year? Cash balance plans carry a funding obligation. There is some flexibility in the range, but plan for the commitment honestly before adopting one.

When do we need to set this up? Deadlines differ by plan type and some are hard year-end dates, so start the conversation by summer rather than December.