Glossary
Safe Harbor 401(k)
A safe harbor 401(k) is a plan design in which the employer commits to a required, immediately vested contribution for employees in exchange for automatic exemption from the main annual nondiscrimination tests.
The standard formulas are a matching contribution (commonly up to 4% of pay for participating employees) or a 3%-of-pay contribution to everyone regardless of participation. Because the tests are deemed passed, owners and highly compensated employees can defer the full IRS limit no matter how much the rest of the staff contributes.
Why it matters in practice
Safe harbor is the default answer for small businesses whose owners want to max out their own retirement savings: without it, low staff participation can cap or refund the owners' contributions after testing. The required contribution is a real cost — but it is deductible compensation to the team, and startup tax credits can offset much of a new plan's early expense.
Related terms: 401(k) · Nondiscrimination Testing · Plan Sponsor · Vesting · CalSavers