(a) The head of an Executive agency may pay an extended assignment incentive to an employee if—

(1) the employee has completed at least 2 years of continuous service in 1 or more civil service positions located in a territory or possession of the United States, the Commonwealth of Puerto Rico, or the Commonwealth of the Northern Mariana Islands;

(2) the agency determines that replacing the employee with another employee possessing the required qualifications and experience would be difficult; and

(3) the agency determines 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 the territory or possession, the Commonwealth of Puerto Rico or Commonwealth of the Northern Mariana Islands, except that the total amount of service performed in a particular territory, commonwealth, or possession under 1 or more agreements established under this section may not exceed 5 years.

(b) The sum of extended assignment incentive payments for a service period may not exceed the greater of—

(1) an amount equal to 25 percent of the annual rate of basic pay of the employee at the beginning of the service period, times the number of years in the service period; or

(2) $15,000 per year in the service period.

(c)

(1) Payment of an extended assignment incentive shall be contingent upon the employee entering into a written agreement with the agency specifying the period of service and other terms and conditions under which the extended assignment incentive is payable.

(2) The agreement shall set forth the method of payment, including any use of an initial lump-sum payment, installment payments, or a final lump-sum payment upon completion of the entire period of service.

(3) The agreement shall describe the conditions under which the extended assignment incentive may be canceled prior to the completion of agreed-upon service period and the effect of the cancellation. The agreement shall require that if, at the time of cancellation of the incentive, the employee has received incentive payments which exceed the amount which bears the same relationship to the total amount to be paid under the agreement as the completed service period bears to the agreed-upon service period, the employee shall repay that excess amount, at a minimum, except that an employee who is involuntarily reassigned to a position stationed outside the territory, commonwealth, or possession or involuntarily separated (not for cause on charges of misconduct, delinquency, or inefficiency) may not be required to repay any excess amounts.

(d) An agency may not put an extended assignment incentive into effect during a period in which the employee is fulfilling a recruitment or relocation bonus service agreement under section 5753 or for which an employee is receiving a retention allowance under section 5754.

(e) Extended assignment incentive payments may not be considered part of the basic pay of an employee.

(f) The Office of Personnel Management may prescribe regulations for the administration of this section, including regulations on an employee's entitlement to retain or receive incentive payments when an agreement is canceled. Neither this section nor implementing regulations may impair any agency's independent authority to administratively determine compensation for a class of its employees.