Tex. Gov't Code § 606.028
(a) As agreed by the retirement system and the governing body of a political subdivision that has an approved plan, the retirement system shall require the political subdivision to pay the subdivision's proportionate share of the state administrative expenses for this subchapter by:
Added by Acts 1993, 73rd Leg., ch. 268, Sec. 1, eff. Sept. 1, 1993.