730 ILCS 150/7
A person who has been adjudicated to be sexually dangerous and is later released or found to be no longer sexually dangerous and discharged, shall register for the period of his or her natural life. A sexually violent person or sexual predator shall register for the period of his or her natural life after conviction or adjudication if not confined to a penal institution, hospital, or other institution or facility, and if confined, for the period of his or her natural life after parole, discharge, or release from any such facility. A person who becomes subject to registration under paragraph (2.1) of subsection (c) of Section 3 of this Article who has previously been subject to registration under this Article shall register for the period currently required for the offense for which the person was previously registered if not confined to a penal institution, hospital, or other institution or facility, and if confined, for the same period after parole, discharge, or release from any such facility. Except as otherwise provided in this Section, a person who becomes subject to registration under this Article who has previously been subject to registration under this Article or under the Murderer and Violent Offender Against Youth Registration Act or similar registration requirements of other jurisdictions shall register for the period of his or her natural life if not confined to a penal institution, hospital, or other institution or facility, and if confined, for the period of his or her natural life after parole, discharge, or release from any such facility. Any other person who is required to register under this Article shall be required to register for a period of 10 years after conviction or adjudication if not confined to a penal institution, hospital or any other institution or facility, and if confined, for a period of 10 years after parole, discharge or release from any such facility. A sex offender who is allowed to leave a county, State, or federal facility for the purposes of work release, education, or overnight visitations shall be required to register within 3 days of beginning such a program. Liability for registration terminates at the expiration of 10 years from the date of conviction or adjudication if not confined to a penal institution, hospital or any other institution or facility and if confined, at the expiration of 10 years from the date of parole, discharge or release from any such facility, providing such person does not, during that period, again become liable to register under the provisions of this Article. Reconfinement due to a violation of parole or other circumstances that relates to the original conviction or adjudication shall extend the period of registration to 10 years after final parole, discharge, or release. Reconfinement due to a violation of parole, a conviction reviving registration, or other circumstances that do not relate to the original conviction or adjudication shall toll the running of the balance of the 10-year period of registration, which shall not commence running until after final parole, discharge, or release. The Director of the Illinois State Police, consistent with administrative rules, shall extend for 10 years the registration period of any sex offender, as defined in Section 2 of this Act, who fails to comply with the provisions of this Article. The registration period for any sex offender who fails to comply with any provision of the Act shall extend the period of registration by 10 years beginning from the first date of registration after the violation. If the registration period is extended, the Illinois State Police shall send a registered letter to the law enforcement agency where the sex offender resides within 3 days after the extension of the registration period. The sex offender shall report to that law enforcement agency and sign for that letter. One copy of that letter shall be kept on file with the law enforcement agency of the jurisdiction where the sex offender resides and one copy shall be returned to the Illinois State Police.
730 ILCS 150/7