(a) When a child who is sentenced to commitment under Section 54.04(d)(3), 54.04(m), or 54.05(f), Family Code, becomes 18 years of age, the department shall evaluate whether the child is in need of additional services that can be completed in the six-month period after the child's 18th birthday to prepare the child for release from the custody of the department or transfer to the Texas Department of Criminal Justice.
(b) This section does not apply to a child who is released from the custody of the department or who is transferred to the Texas Department of Criminal Justice before the child's 18th birthday.