(a)
On request from or with the concurrence of a State or local government, and with the consent of the employee concerned, the head of a Federal agency may arrange for the assignment of—
(1)
an employee of his agency, other than a noncareer appointee, limited term appointee, or limited emergency appointee (as such terms are defined in section
3132
(a) of this title) in the Senior Executive Service and an employee in a position which has been excepted from the competitive service by reason of its confidential, policy-determining, policy-making, or policy-advocating character, to a State or local government; and
(2)
an employee of a State or local government to his agency;
for work of mutual concern to his agency and the State or local government that he determines will be beneficial to both. The period of an assignment under this subchapter may not exceed two years. However, the head of a Federal agency may extend the period of assignment for not more than two additional years. In the case of assignments made to Indian tribes or tribal organizations as defined in section 3371(2)(C) of this subchapter, the head of an executive agency may extend the period of assignment for any period of time where it is determined that this will continue to benefit both the executive agency and the Indian tribe or tribal organization. If the assigned employee fails to complete the period of assignment and there is another employee willing and available to do so, the Secretary may assign the employee to complete the period of assignment and may execute an agreement with the tribal organization with respect to the replacement employee. That agreement may provide for a different period of assignment as may be agreed to by the Secretary and the tribal organization.