405 ILCS 5/5-106
The rate at which sums for the services to recipients in a mental health or developmental disabilities program of the Department is calculated by the Department is the average per capita cost of the services to all such recipients, such cost to be computed by the Department on the general average per capita cost of operation of all State facilities for the fiscal year immediately preceding the period of State care for which the rate is being calculated, except the Department may, in its discretion, set the rate at a lesser amount than such average per capita cost. The Department in its rules and regulations may establish a maximum rate not to exceed the rate set by the Office of Health Finance for the cost of services furnished to persons in mental health or developmental disabilities programs involving residential care. If a recipient is placed in a residential program or facility outside the Department, the ability of responsible relatives to pay these costs shall be determined under Section 5-116 of this Act. The Department may supplement the contribution of these persons to private facilities after all other sources of income have been utilized, provided responsible relatives do not contribute to actual cost of services in excess of amounts charged to responsible relatives as established under Section 5-116 of this Act. The Department shall make an annual report to the Commission on Mental Health and Developmental Disabilities setting forth proposed changes in rules and regulations relating to Sections 5-105 through 5-115 and summarizing all amounts expended by the Department on behalf of recipients in private facilities. The Department may pay the actual costs of services or maintenance in such facility and may collect reimbursement for the entire amount paid from the recipient, or an amount not to exceed the amount listed in Section 5-106 of this Act from responsible relatives according to their proportionate ability to contribute to such charges. Lesser or greater amounts may be accepted by the Department when conditions warrant such action or when offered by persons not liable under this Act. The amounts so received shall be deposited with the State Treasurer and placed in the Mental Health Fund.
405 ILCS 5/5-106