20 ILCS 505/9.4
The Department shall review the forms or questionnaires returned by each parent or guardian and supplement the information provided therein, where required, by such additional consultations with the parent or guardian and such other investigations as may be necessary and, applying the standard and regulations established by the Department, shall determine whether and the extent to which, the parent or guardian individually or together in any combination, are reasonably able to provide parental payment for care and training of their children.
The Department, by rule, may conduct periodic or other reinvestigations and redeterminations of the financial ability of parents or guardians. Any redeterminations shall have the effect of altering, amending, or modifying previous determinations. However, any redetermination which established liability for parental payment of reimbursement, or which increases the support or reimbursement liability specified in a prior order, shall be subject to the provisions of Section 9.9 in the administrative and judicial review procedures herein provided for original orders.
20 ILCS 505/9.4