401(k) + Profit Sharing, Owner-Designed
A properly designed 401(k) with class-based profit sharing can hold $72,000 a year of contributions before any pension enters the picture, plus catch-ups from age 50. This guide covers safe harbor, class-based allocation, Roth options, and how the plan becomes the foundation under a cash balance plan.
Reviewed by Alexander Tecle, MBA, MS Taxation
President & Founder · Verify on SEC IAPD (opens in a new tab)
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Most business 401(k)s are built for participation, not for owners. An owner-designed plan flips the emphasis: safe-harbor status to clear testing automatically, a class-based ("new comparability") profit-sharing formula that directs employer dollars by group, Roth and after-tax options for tax diversification, and vesting schedules that make staff contributions serve as retention.
It matters twice. As a standalone plan, it is the right choice for owners not yet ready for a pension's funding commitment. Under a cash balance plan, it is the required foundation: the deferral, the safe harbor, and employer contributions held to the 6% line are required parts of the combined design.
On this page
Calculators
| Limit | 2026 | 2025 |
|---|---|---|
| 401(k) / 403(b) employee contribution | $24,500 | $23,500 |
| Catch-up contribution (age 50+) | $8,000 | $7,500 |
| Higher catch-up (ages 60–63)Unchanged for 2026 (SECURE 2.0). | $11,250 | $11,250 |
| Total additions to a defined contribution plan — IRC 415(c)Employer + employee; excludes age-based catch-up. | $72,000 | $70,000 |
| Compensation that can be counted — IRC 401(a)(17) | $360,000 | $350,000 |
Official IRS figures for 2026. Source: IRS Notice 2025-67 (IR-2025-111).
The pieces of an owner-designed 401(k)
Three pieces, layered in this order, let a solo owner or owner-heavy business reach the full ceiling with modest staff cost.
Employee deferral: $24,500 for 2026, plus catch-ups from age 50, pre-tax or Roth at your election each year.
Safe harbor: a 3% employer contribution that exempts the plan from the ADP testing that otherwise limits high earners' deferrals.
Profit sharing: a discretionary employer layer up to the $72,000 total-additions ceiling, allocated by class so owners and staff can receive different percentages within nondiscrimination testing.
Class-based allocation: the design that changed profit sharing
Old profit sharing gave everyone the same percentage. Class-based designs define groups (owners, managers, staff) and test the allocation on projected benefits, which lets an older owner's percentage run far above the staff's while passing 401(a)(4). It is the same cross-testing method used in combined cash balance designs, applied inside the 401(k) alone; the employees guide explains the testing in plain language.
Employee deferral
The participant elects pre-tax or Roth deferrals, with an age-based catch-up when eligible.
Safe harbor
The employer layer clears the deferral-testing barrier described in this guide.
Profit sharing
A discretionary employer layer allocates contributions by class within nondiscrimination rules.
Limits and testing
The full allocation stays within annual additions limits and passes the required testing.
Combined plan
The coordinated layers work alone or become the foundation beneath a cash balance plan.
Roth, after-tax, and the mega backdoor
The 401(k) is also where tax diversification lives, through Roth deferrals and, in plans designed for it, after-tax contributions converted to Roth (the "mega backdoor"), which can move tens of thousands a year into Roth treatment (tax-free growth, with qualified withdrawals tax-free) alongside the deductible stack. High earners with wages above the SECURE 2.0 threshold should also know the rule that pushes their age-based catch-up to Roth. These options cost little to include at design time and are painful to retrofit.
As the foundation under a cash balance plan
When a pension joins, the 401(k) becomes part of the structure. The safe-harbor contribution keeps testing clean, the deferral rides on top untouched, and profit sharing is deliberately set at 6% of pay because the combined-plan deduction rule (IRC 404(a)(7)) protects the full pension deduction only when employer DC money stays at or under that line. If a cash balance plan is anywhere in your future, build the 401(k) as if the pension were already here.
Related articles
What is a 401(k) Profit Sharing Plan?Explore the benefits and considerations of a 401(k) Profit Sharing Plan, including its advantages for financial flexibility, employee retention, and supplemental savings.
What Are Alternatives to a 401(k) Profit Sharing Plan?Explore alternatives to the traditional 401(k) Profit Sharing Plan, including Safe Harbor 401(k) Plans, Cash Balance Pension Plans, and Non-Qualified Deferred Compensation Plans.
Introduction to Safe Harbor 401(k) Plans and Cash Balance Pension PlansExplore the benefits and features of Safe Harbor 401(k) Plans and Cash Balance Pension Plans. Learn how these retirement plans can offer significant tax deferral advantages and how combining them can maximize benefits for business owners and employees.
Frequently asked questions
How much can I put into a 401(k) with profit sharing?
For 2026: $24,500 of deferral ($32,500 with the age-50 catch-up) plus employer contributions up to a $72,000 total-additions ceiling (catch-ups ride on top). Reaching the ceiling at moderate W-2 levels is a design exercise — that's what the profit-sharing formula is for.
What does safe harbor buy me?
Automatic passage of the deferral testing that otherwise caps high earners when staff participation is low, in exchange for a 3% employer contribution (or a matching formula). For owner-heavy businesses it usually pays for itself in unlocked deferrals.
Can owners get a bigger profit-sharing percentage than staff?
Yes — class-based allocations tested on projected benefits often support meaningfully higher owner percentages, especially when owners are older than staff. The design must pass annual nondiscrimination testing.
Should I set this up even if I want a cash balance plan later?
Especially then. The combined design needs a safe-harbor 401(k) with profit sharing at 6% — building it that way now means adding the pension later is an addition rather than a rebuild.
Sources
- IRC §401 — qualified plan requirements (401(a)(4), 401(a)(17), 401(k)) (opens in a new tab)
- IRC §415 — benefit and contribution limits (opens in a new tab)
- 26 CFR 1.401(k)-3 — safe harbor 401(k) requirements and notice timing (opens in a new tab)
- 26 CFR 1.401(a)(4)-8 — cross-testing on projected benefits (opens in a new tab)
- IRS — 401(k) and profit-sharing plan contribution limits (opens in a new tab)
- IRS — Designated Roth account FAQs (opens in a new tab)
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Run your age-and-income number
Two inputs — your age and your compensation — give a modeled cash balance contribution for the current plan year in about a minute. It is an illustration built on stated assumptions, not a quote; the plan's actuary sets the final figure.
This guide is educational and is not individualized tax, legal, or investment advice. Contribution limits and tax rules change annually and depend on your specific situation; figures are illustrative. Consult a qualified professional before acting.