N.H. Rev. Stat. Ann. § 621:24

No administrative release or parole of a child shall operate as a discharge of the child from the center. The department shall continue to have control of children on administrative release to parole or parole until they reach the age of 18 years, and the control conferred by the department upon others shall be conferred upon them as agents of the department, except where a child is discharged under RSA 621:19.