5 CFR § 352.307 - Eligibility for transfer.
An employee is eligible for transfer to an international organization with the rights provided for in, and in accordance with, sections 3581–3584 of title 5, United States Code, and this subpart, except the following:
(a) A Presidential appointee (other than a postmaster, a Foreign Service officer or a Foreign Service information officer), regardless of whether his appointment was made by and with the advice and consent of the Senate.
(b) A person serving in the executive branch in a confidential or policy-determining position excepted from the competitive service under Schedule C of part 213 of this chapter.
(c) A person serving under a noncareer, limited emergency, or limited term appointment in the SES.
(d) A person serving under a temporary appointment pending establishment of a register.
(e) A person serving under an appointment specifically limited to 1 year or less.
(f) A person serving on a seasonal, intermittent, or part-time basis.