A safe harbor 401(k) plan is similar to a traditional 401(k) plan, but, among other things, it must provide for employer contributions that are fully vested when made. These contributions may be employer matching contributions, limited to employees who defer, or employer contributions made on behalf of all eligible employees, regardless of whether they make elective deferrals. The safe harbor 401(k) plan is not subject to the complex annual nondiscrimination tests that apply to traditional 401(k) plans.