On June 10, 2015, Gov. Greg Abbott signed a bill that requires state agencies and institutions of higher education to use E-Verify. The new law does not supersede* an executive order by former Gov. Rick Perry that also required state contractors and sub-contractors to enroll in E-Verify to qualify for public contracts.
While numerous bills requiring E-Verify for private employers (those without state contracts) have been considered by committees of the Texas State Legislature, none have made it through the process to enactment. E-Verify remains voluntary for Texas employers; however, thousands of Texas employers have enrolled in the service that is offered by Verify I-9, LLC.
* I’m confused! Do state contractors have to enroll or not?
In an opinion issued on 3/16/2016, Attorney General Ken Paxton said the 2015 law, which does not expressly require contractors to use E-Verify, does not supersede the 2014 executive order requiring state agencies and the companies they contract with to use the E-Verify system. In other words, the original order requiring contractors to use E-Verify is still in effect. News source