What does the actual deferral percentage (ADP) test measure in a 401(k) plan?

The actual deferral percentage (ADP) test specifically evaluates the deferral rates of Highly Compensated Employees (HCEs) in relation to those of Non-Highly Compensated Employees (NHCEs) within a 401(k) plan. This measurement is critical for ensuring compliance with Internal Revenue Service (IRS) regulations that aim to prevent discrimination in favor of HCEs.

By comparing the contribution rates of these two groups, the ADP test helps maintain balanced participation and benefits across the workforce. If HCEs are allowed to defer significantly more than NHCEs, it could indicate an imbalance that could lead to plan disqualification or penalties, emphasizing the need for equitable access to retirement benefits among all employees.

Other options do not accurately reflect the purpose of the ADP test. The total amount deferred by all employees relates more to overall plan contributions rather than the specific rates of HCEs compared to NHCEs. The employer's contribution rate compared to employees’ rates is assessed through different compliance tests, while catch-up contributions focus on specific additional contributions permitted for older participants, which are not evaluated under the ADP test.