In this chapter:
(1) “Social security coverage” means federal old-age, survivors, and disability insurance benefits under 42 U.S.C. Chapter 7, Subchapter II.
(2) “Federal Insurance Contributions Act” means 26 U.S.C. Chapter 21.
(3) “Political subdivision” includes:
(A) a county;
(B) a municipality; or
(C) an instrumentality of the state, of another political subdivision, or of the state and another political subdivision:
(i) that is a juristic entity that is legally separate and distinct from the state or political subdivision; and
(ii) whose employees are not employees of the state or political subdivision.
(4) “Retirement system” means the Employees Retirement System of Texas.
(5) “Secretary” means the United States Secretary of Health and Human Services or an individual designated by the secretary to administer coverage of the Social Security Act to employees of a state and its political subdivisions.
(6) “Social Security Act” means Chapter 7, Title 42, United States Code (42 U.S.C. § 301 et seq.), including regulations and requirements adopted under that chapter.