Vt. Stat. Ann. tit. 28, § 705

If it is determined by the Commissioner of Mental Health that a person who has been transferred by the Commissioner to the Department of Mental Health is in need of further care and treatment after the expiration of his or her maximum sentence, the Commissioner of Mental Health shall petition the Criminal Division of the Superior Court for recommitment of the inmate to the custody of the Commissioner of Mental Health. This action by the Commissioner of Mental Health shall be initiated before the expiration of the maximum sentence.