Service to an employer that is recognized for the defined benefit pension plan purposes, but either occurred before the employee was a member in the plan, or before the plans inception. Employees have the option to purchase past service, by cash or by qualified retirement plan roll-over, to increase their years of service in the calculation of their retirement pension.

In cases where employees are considering rolling over the assets from their qualified retirement plan, it is often wise to first consult a financial planner. Depending on a number of factors, such as employee life expectancy, marital status and quality of the pension plan, it may or may not be beneficial to make the roll-over.