(a)  A limited appointment in the Service, including an appointment of an individual who is an employee of an agency, may not exceed 5 years in duration and, except as provided in subsections (b) and (c), may not be extended or renewed. A limited appointment in the Service which is limited by its terms to a period of one year or less is a temporary appointment.

(b)  A limited appointment may be extended for continued service⁠—

(1)  as a consular agent;

(2)  in accordance with section 3951(a) of this title;

(3)  as a career candidate, if⁠—

(A)  continued service is determined appropriate to remedy a matter that would be cognizable as a grievance under subchapter XI; or

(B)  the individual is serving in the uniformed services (as defined in section 4303 of title 38) and the limited appointment expires in the course of such service;

(4)  as a career employee in another Federal personnel system serving in a Foreign Service position on detail from another agency;

(5)  as a foreign national employee;

(6)  in exceptional circumstances if the Secretary determines the needs of the Service require the extension of⁠—

(A)  a limited noncareer appointment for a period not to exceed 1 year; or

(B)  a limited appointment of a career candidate for the minimum time needed to resolve a grievance, claim, investigation, or complaint not otherwise provided for in this section.

(c) (1)  Except as provided in paragraph (2) noncareer employees who have served for 5 consecutive years under a limited appointment under this section may be reappointed to a subsequent noncareer limited appointment if there is at least a 1-year break in service before such new appointment.

(2)  The Secretary may waive the 1-year break requirement under paragraph (1) in cases of special need.