Defined Benefit Plans for Business Owners

A defined contribution plan (401(k), SEP, profit sharing) limits the inputs: a fixed dollar amount may go in each year, and the participant bears the investment outcome. A defined benefit plan flips this. The plan document promises an output (a benefit at retirement, up to the IRS maximum), and each year an actuary determines the contribution required to stay on track to deliver it. The business funds it and deducts it.

Because the benefit is fixed and the years to fund it shrink, the required (and deductible) annual contribution grows with age, often into the $150,000–$300,000+ range for owners in their 50s and 60s. That is why DB plans dominate high-income tax planning.

Owners today choose between three DB structures. All three share the same legal framework; the differences are how the benefit is expressed and how the money is invested.

The contribution is not chosen; it is calculated. The actuary starts from the benefit (capped for 2026 at a $290,000-per-year annuity under IRC 415(b), built on compensation up to $360,000 under IRC 401(a)(17)), then discounts it back through your age and the plan's assumptions to a required annual funding amount. Age is the dominant variable: a 55-year-old funding the same benefit as a 40-year-old has fifteen fewer years, so each of their remaining years carries a far larger, far more deductible contribution.

Nearly every owner design pairs the DB plan with a 401(k) and a small profit-sharing contribution, stacking the flat DC limits on top of the actuarial DB amount. The combined-plan deduction rules shape that pairing; see the S-Corp guide for the 6% rule that keeps the stack fully deductible.

A DB plan carries a funding obligation: a contribution is expected every year the plan is active, within a range the actuary sets annually. The obligation is what the larger deduction costs, which is why these plans belong in businesses with steady profits. The commitment is manageable (plans can be amended to adjust future benefits, frozen to pause accruals in a hard year, and ultimately terminated, with participants typically rolling their benefit into an IRA), but each of those moves has process and timing rules.

Two more points belong up front. First, well-performing market-invested plans can become overfunded, which threatens the deduction that justified the plan; it is solvable (that is what pension rescue is) but must be managed before year-end. Second, many small plans, including owner-only plans and professional practices with 25 or fewer active participants, are exempt from PBGC coverage and premiums, which keeps administration lean.

If you are under roughly $150,000 of steady profit, a Solo 401(k) usually wins on flexibility and cost: max it before adding anything. The DB conversation starts when you are consistently earning well beyond what a 401(k) can shelter and you want the tax deduction this year rather than spread over a decade. Start from how much income you need to shelter. A 401(k) tops out at $72,000 of total additions for 2026; a DB plan for an owner in their mid-50s can fund a multiple of that.

The deciding question is funding tolerance. A DB plan expects a contribution every year inside the actuary's range, so it belongs in a business whose profits can carry that range through a weak year without strain; the size of the deduction is the reward for accepting that obligation. Owners who pass that test and want to fund in ten years what would otherwise take twenty are the core candidates. Employees don't rule it out: cross-tested combination designs cover staff while keeping the owner's share of funding high, as the case studies show.