Texas Human Resources Code - HUM RES § 245.151. Termination of Control

(a) Except as provided by Subsections (b) and (c), if a person is committed to the department under a determinate sentence under Section 54.04(d)(3), Section 54.04(m), or Section 54.05(f), Family Code, the department may not discharge the person from its custody.

(b) The department shall discharge without a court hearing a person committed to the department for a determinate sentence under Section 54.04(d)(3), Section 54.04(m), or Section 54.05(f), Family Code, who has not been transferred to the Texas Department of Criminal Justice under a court order on the date that the time spent by the person in detention in connection with the committing case plus the time spent at the department under the order of commitment equals the period of the sentence.

(c) The department shall transfer to the Texas Department of Criminal Justice a person who is the subject of an order under Section 54.11(i)(2), Family Code, transferring the person to the custody of the Texas Department of Criminal Justice for the completion of the person's sentence.

(d) Except as provided by Subsection (e), the department shall discharge from its custody a person not already discharged on the person's 19th birthday.

(e) The department shall transfer a person who has been sentenced under a determinate sentence to commitment under Section 54.04(d)(3), 54.04(m), or 54.05(f), Family Code, or who has been returned to the department under Section 54.11(i)(1), Family Code, to the custody of the Texas Department of Criminal Justice on the person's 19th birthday, if the person has not already been discharged or transferred, to serve the remainder of the person's sentence on parole as provided by Section 508.156, Government Code.