Safe Harbor 401(k): How Owners Avoid Failed Testing and Refunds

In a small business, the owner is often the person who most wants to save — and the person most likely to be limited by the plan's annual tests. A safe harbor 401(k) is the usual fix.

The problem: nondiscrimination testing

Every traditional 401(k) must pass annual tests (the ADP and ACP tests) comparing what highly compensated employees save with what everyone else saves. For 2026, a highly compensated employee is generally a 5% owner or someone who earned more than $160,000 in the prior year.

If rank-and-file employees save little, the plan can fail. The usual correction is returning part of the owner's contributions — as taxable income — or making extra corrective contributions for employees.

The fix: a safe harbor contribution

A safe harbor plan skips those tests in exchange for a required, fully vested employer contribution. The common designs:

• Basic match: 100% of the first 3% of pay an employee defers, plus 50% of the next 2% (a maximum of 4% of pay).
• Enhanced match: commonly 100% of the first 4% of pay.
• Nonelective: 3% of pay to every eligible employee, whether or not they save.

With safe harbor in place, owners can generally defer the full $24,500 for 2026 (plus catch-up) without worrying about refunds. A plan that holds only deferrals and safe harbor contributions is also generally exempt from top-heavy rules — a frequent issue in owner-heavy businesses.

When it makes sense

• The owner or key staff want to max out their deferrals.
• Employee participation is modest.
• The business can commit to the contribution each year.

Timing matters

Safe harbor features have notice and timing rules, and some designs must be in place months before year-end. Plan design conversations belong in the first half of the year, not in December.

General educational information as of September 22, 2026; limits and rules change. Not individualized investment, tax or legal advice. Consult your tax adviser about your situation.