The Cash Balance Plan Tax Deduction

The employer contribution (the cash balance funding, profit sharing, and any 401(h) amount) follows the business return. Your personal 401(k) deferral never appears here; it reduces your W-2 Box 1 wages (or, for the self-employed, is claimed with the personal-side deduction).

In a partnership or multi-member LLC the firm sponsors the plan, but a partner's own contribution is not a firm expense: it passes through on Schedule K-1 (Form 1065), Box 13, code R, and the partner deducts it on Schedule 1 of their own Form 1040, subject to the earned-income rules in IRC 404(a)(8). Contributions for common-law employees stay on the partnership return as an ordinary deduction. Because each partner's pension cost lands on that partner, partners can carry different contribution levels within one tested plan, which is why per-partner tiers are standard in professional firms.

A C-corporation is the simplest case on paper: the corporation deducts the contribution on Form 1120 against income taxed at the flat corporate rate, and nothing passes through to the owner's personal return. The owner participates only through W-2 wages, so the salary level drives capacity as it does for an S-Corp, and the plan is one route for corporate profit to reach the owner's retirement account without the dividend layer of tax. Partnership and C-corporation questions are folded into this guide because the deduction mechanics, rather than the plan design, are what differ.

For sole proprietors and partners, the pension deduction reduces income tax but not self-employment tax: SE tax is computed on net business earnings before the retirement deduction. The asymmetry is one reason high earners consider an S-Corp election; on the S-Corp side, the compensation planning happens through the W-2 instead. The S-Corp guide walks through that trade in detail.

Two carve-outs keep the total accurate. Your own 401(k) deferral is already pre-tax through payroll, so counting it again double-dips. For high earners with W-2 wages above the law's threshold, SECURE 2.0 requires the age-based catch-up to be made as Roth, which is after-tax by definition (self-employed owners without wages are not subject to it); a correct illustration lists it separately from the deductible stack.

The first rule concerns adoption. Under the SECURE Act, an employer can adopt a new employer-funded plan as late as its tax-filing deadline including extensions and treat it as adopted for the prior year, so a strong year that already ended can still get a cash balance deduction. The second concerns funding. Contributions for a plan year can generally be made up to the return's extended due date and still be deducted for that year. Together they move the deadline conversation to tax time, though employee deferrals can never be made retroactively, and waiting crowds the design work into a few weeks.

The ceiling is actuarial rather than a flat number. The plan may fund a benefit up to the IRS annual cap (see the limits table above), and your age and compensation translate that into this year's contribution. Combined with a 401(k) and profit sharing, older owners can reach the mid six figures of total deductible contributions; the calculator turns your own inputs into the estimate.