Tex. Elec. Code § 82.004
(a) A qualified voter is eligible for early voting by mail if, at the time the voter's early voting ballot application is submitted, the voter is confined in jail:
Acts 1985, 69th Leg., ch. 211, Sec. 1, eff. Jan. 1, 1986.
Amended by Acts 1987, 70th Leg., ch. 472, Sec. 19, eff. Sept. 1, 1987;
Acts 1991, 72nd Leg., ch. 554, Sec. 1, eff. Sept. 1, 1991. Renumbered from Election Code Sec. 82.005 and amended by Acts 1991, 72nd Leg., ch. 203, Sec. 1.02;
Acts 1997, 75th Leg., ch. 864, Sec. 70, eff. Sept. 1, 1997.