5 C.F.R. § 334.102
In this part:
Assignment means a period of service under chapter 33, subchapter VI of title 5, United States Code;
Employee, for purposes of participation in this Program, means an individual serving in a Federal agency under a career or career-conditional appointment, including a career appointee in the Senior Executive Service, an individual under an appointment of equivalent tenure in an excepted service position, or an individual employed for at least 90 days in a career position with a State, local, or Indian tribal government, institution of higher education, or other eligible organization;
Federal agency as defined in 5 U.S.C. 3371(3) means an Executive agency, military department, a court of the United States, the Administrative Office of the United States Courts, the Library of Congress, the Botanic Garden, the Government Printing Office, the Congressional Budget Office, the United States Postal Service, the Postal Rate Commission, the Office of the Architect of the Capitol, the Office of Technology Assessment, and such other similar agencies of the legislative and judicial branches as determined appropriate by the Office of Personnel Management;
Indian tribal government as defined in 5 U.S.C. 3371(2)(c) means any Indian tribe, band, nation, or other organized group or community, including any Alaska Native village as defined in the Alaska Native Claims Settlement Act (85 Stat. 668), which is recognized as eligible for the special programs and services provided by the United States to Indians because of their status as Indians and includes any tribal organization as defined in section 4(c) of the Indian Self-Determination and Education Assistance Act;
Institution of higher education means a domestic, accredited public or private 4-year and/or graduate level college or university, or a technical or junior college;
Local government as defined in 5 U.S.C. 3371(2)(A) and (B) means:
(1) Any political subdivision, instrumentality, or authority of a State or States; and
(2) Any general or special purpose agency of such a political subdivision, instrumentality, or authority;
Other organization as defined in 5 U.S.C. 3371(4) means:
(1) A national, regional, Statewide, area wide, or metropolitan organization representing member State or local governments;
(2) An association of State or local public officials;
(3) A nonprofit organization which offers, as one of its principal functions, professional advisory, research, educational, or development services, or related services, to governments or universities concerned with public management; or
(4) A federally funded research and development center.
State as defined in 5 U.S.C. 3371(1) means a State of the United States, the District of Columbia, the Commonwealth of Puerto Rico, the Trust Territory of the Pacific Islands, the Northern Mariana Islands, and a territory or possession of the United States; an instrumentality or authority of a State or States; and a Federal-State authority or instrumentality.
5 C.F.R. §334.102