Tex. Gov't Code § 830.106
A participant in the optional retirement program is not eligible for membership in the retirement system unless the person:
Acts 1981, 67th Leg., p. 1876, ch. 453, Sec. 1, eff. Sept. 1, 1981. Renumbered from Vernon's Ann.Civ.St. Title 110B, Sec. 36.106 by Acts 1989, 71st Leg., ch. 179, Sec. 1, eff. Sept. 1, 1989.
Amended by Acts 1995, 74th Leg., ch. 586, Sec. 34, eff. Aug. 28, 1995.