Eligibility refers to the age, service, and other requirements imposed on employees before they can participate in a plan.

ERISA (Employee Retirement Income Security Act of 1974) is the set of Federal Tax and Labor Laws that govern qualified plans. These override most State law.

Forfeitures are the non-vested amounts that are reallocated among other participants (or reduce contributions), ordinarily when a participant terminates employment.

Highly Compensated Employee is an employee who meets certain ownership, management, and/or compensation levels. A number of rules limit the extent to which plans can favor highly compensated employees.