Section 39.502 - Cost-Of-Service Regulation(a) Until the date on which an electric utility subject to this subchapter is authorized by the commission under Section 39.503(f) to implement retail customer choice, the rates of the utility are subject to regulation under Chapter 36.(b) Until the date on which an electric utility subject to this subchapter implements customer choice, the provisions of this chapter, other than this subchapter and Sections 39.1516 and 39.905, do not apply to that utility. Amended by Acts 2023, Texas Acts of the 88th Leg.- Regular Session, ch. 410,Sec. 32, eff. 9/1/2023.Amended by: Acts 2019, 86th Leg., R.S., Ch. 610 (S.B. 936), Sec. 6, eff. September 1, 2019Added by Acts 2009, 81st Leg., R.S., Ch. 128 (S.B. 547), Sec. 1, eff. September 1, 2009.