Tex. Gov't Code § 651.005
(a) An agency in any branch of state government may not hire a person as an employee if the person is of the age and gender that would require a person residing in the United States to register with the selective service system under federal law, unless the person presents proof of the person's:
Added by Acts 1999, 76th Leg., ch. 171, Sec. 1, eff. Sept. 1, 1999.