As used in this chapter, unless the context requires a different meaning: “Agreement” means the federal-state agreement between the federal agency and the Commonwealth entered into on February 16, 1952, as authorized by this chapter, for the purpose of extending coverage under the Social Security Act and any subsequent modifications thereto. “Applicable federal law” refers to provisions of federal law, including federal regulations and requirements issued pursuant thereto, that provide for extending the benefits of the Social Security Act and the Federal Insurance Contributions Act to employees of states and their political subdivisions. “Board” means the Board of Trustees of the Virginia Retirement System. “Employee tax” means the tax imposed by § 3101 of the Internal Revenue Code of 1986, as amended. “Employer” means the Commonwealth or a political subdivision thereof, as defined in this chapter. “Employment” means employment as defined in the Social Security Act as modified under the terms of the agreement and pursuant to the authority granted the state social security administrator under § 51.1-707. “Federal agency” means the federal officer, department, or agency charged on behalf of the federal government with the particular federal functions referred to in this chapter in connection with such term. “Federal Insurance Contributions Act” means subchapters A and B of Chapter 21 of the Internal Revenue Code of 1986, as amended. “Local employee” means any officer or employee of a political subdivision and includes “special employees,” which means a county or city treasurer, commissioner of revenue, attorney for the Commonwealth, clerk of court, sheriff, and a deputy or employee of any such officer. “Modification” means an amendment to the original agreement to modify coverage for coverage groups or to extend coverage to additional coverage groups consistent with the provisions of Section 218 of the Social Security Act and this chapter. “Plan of agreement” means an agreement between the state social security administrator and an employer for the purpose of extending the benefits of the Social Security Act to coverage groups within its employ. “Political subdivision” includes an instrumentality of the Commonwealth or one or more of its political subdivisions, or of the Commonwealth and one or more of its political subdivisions, but only if such instrumentality is a juristic entity which is legally separate and distinct from the Commonwealth or a political subdivision and only if its employees are not by virtue of their relation to such juristic entity employees of the Commonwealth or a political subdivision. “Political subdivision” includes Indian tribes. “Social Security Act” means the act of Congress approved August 14, 1935, Chapter 531, 49 Statutes 620, officially cited as the “Social Security Act,” as such act has been and may be amended. “State employee” means any person who is employed in the service of the Commonwealth but shall not include any member of the General Assembly or local employee. “State social security administrator” means the Director of the Virginia Retirement System. “Teacher” means any person who is regularly employed on a salaried basis as a professional or clerical employee of a county, city, or other local public school board. “Wages” means all remuneration for employment, including the cash value of all remuneration paid in any medium other than cash, except that part of such remuneration which, even if it were paid for “employment” within the meaning of the Federal Insurance Contributions Act, would not constitute “wages” within the meaning of that act.