Local Government Code §143.021

(a) The commission shall provide for the classification of all fire fighters and police officers. The municipality's governing body shall establish the classifications by ordinance. The governing body by ordinance shall prescribe the number of positions in each classification. (b) Except for the department head and a person the department head appoints in accordance with Section 143.014 or 143.102 , each fire fighter and police officer is classified as prescribed by this subchapter and has civil service protection. The failure of the governing body to establish a position by ordinance does not result in the loss of civil service benefits by a person entitled to civil service protection or appointed to the position in substantial compliance with this chapter. (c) Except as provided by Sections 143.013 , 143.014 , 143.0251 , 143.102 , and 143.1251 , an existing position or classification or a position or classification created in the future either by name or by increase in salary may be filled only from an eligibility list that results from an examination held in accordance with this chapter.