(a) An employee serving under an appointment not limited to 1 year or less who transfers to an international organization with the consent of the head of his agency is entitled—

(1) to retain coverage, rights, and benefits under any system established by law for the retirement of employees, if necessary employee deductions and agency contributions in payment for the coverage, rights, and benefits for the period of employment with the international organization are currently deposited in the system's fund or depository; and the period during which coverage, rights, and benefits are retained under this paragraph is deemed creditable service under the system, except that such service shall not be considered creditable service for the purpose of any retirement system for transferring personnel, if such service forms the basis, in whole or in part, for an annuity or pension under the retirement system of the international organization;

(2) to retain coverage, rights, and benefits under chapters 87 and 89 of this title, if necessary employee deductions and agency contributions in payment for the coverage, rights, and benefits for the period of employment with the international organization are currently deposited in the Employees' Life Insurance Fund and the Employees' Health Benefits Fund, as applicable, and the period during which coverage, rights, and benefits are retained under this paragraph is deemed service as an employee under chapters 87 and 89 of this title;

(3) to retain coverage, rights, and benefits under subchapter I of chapter 81 of this title, and for this purpose his employment with the international organization is deemed employment by the United States, but if he or his dependents receive from the international organization a payment, allowance, gratuity, payment under an insurance policy for which the premium is wholly paid by the international organization, or other benefit of any kind on account of the same injury or death, the amount thereof is credited against disability or death compensation, as the case may be, payable under subchapter I of chapter 81 of this title; and

(4) to elect to retain to his credit all accumulated and current accrued annual leave to which entitled at the time of transfer which would otherwise be liquidated by a lump-sum payment. On his request at any time before reemployment, he shall be paid for the annual leave retained. If he receives a lump-sum payment and is reemployed within 6 months after transfer, he shall refund to the agency the amount of the lump-sum payment. This paragraph does not operate to cause a forfeiture of retained annual leave following reemployment or to deprive an employee of a lump-sum payment to which he would otherwise be entitled.

(b) An employee entitled to the benefits of subsection (a) of this section is entitled to be reemployed within 30 days of his application for reemployment in his former position or a position of like seniority, status, and pay in the agency from which he transferred, if—

(1) he is separated from the international organization within 5 years, or any extension thereof, after entering on duty with the international organization or within such shorter period as may be named by the head of the agency at the time of consent to transfer; and

(2) he applies for reemployment not later than 90 days after the separation.

On reemployment, an employee entitled to the benefits of subsection (a) is entitled to the rate of basic pay to which the employee would have been entitled had the employee remained in the civil service. On reemployment, the agency shall restore the sick leave account of the employee, by credit or charge, to its status at the time of transfer. The period of separation caused by the employment of the employee with the international organization and the period necessary to effect reemployment are deemed creditable service for all appropriate civil service employment purposes. This subsection does not apply to a congressional employee.

(c) This section applies only with respect to so much of a period of employment with an international organization as does not exceed 5 years, or any extension thereof, or such shorter period named by the head of the agency at the time of consent to transfer, except that for retirement and insurance purposes this section continues to apply during the period after separation from the international organization in which—

(1) an employee, except a Congressional employee, is properly exercising or could exercise the reemployment right established by subsection (b) of this section; or

(2) a Congressional employee is effecting or could effect a reemployment.

During that reemployment period, the employee is deemed on leave without pay for retirement and insurance purposes.

(d) During the employee's period of service with the international organization, the agency from which the employee is transferred shall make contributions for retirement and insurance purposes from the appropriations or funds of that agency so long as contributions are made by the employee.