Idaho Code § 18-8410
When a registered juvenile sex offender reaches twenty-one (21) years of age, the prosecutor may petition the court to transfer the offender to the adult registry, subject to the registration and notification provisions of chapter 83, title 18, Idaho Code. If the court determines at a hearing that the juvenile sex offender is likely to pose a threat to the safety of others, the court shall order that the delinquent act be deemed an adult criminal conviction for the purpose of registration, notification, and public information access pursuant to chapter 83, title 18, Idaho Code. If no petition is filed, or if the court determines the juvenile is not likely to pose a threat to the safety of others, the juvenile shall be deleted from the registry.
Idaho Code § 18-8410