(a) An agency must base the payment of an extended assignment incentive on a written determination that—

(1) The eligible employee has completed at least 2 years of continuous service immediately before the commencement of the service agreement in one or more civil service positions located in a particular territory, possession, or commonwealth;

(2) It is in the best interest of the Government to encourage the employee to complete a specified additional period of employment with the agency in that location; and

(3) Replacing the employee with another employee possessing the required qualifications and experience would be difficult.

(b) In determining whether it is in the best interest of the Government to retain an employee under paragraph (a)(2) of this section, an agency may consider how the employee's departure would affect the agency's ability to operate effectively or to carry out an activity or perform a function which the agency deems essential to its mission.

(c) Any determination to approve an extended assignment incentive must be made on a case-by-case basis for each employee. However, an agency may consider common factors that apply to a category of employees, such as past recruitment and retention problems or the anticipation of such problems in the future.