405 ILCS 5/5-108
The Department may investigate the financial condition of each person liable under this Act, may make determinations of the ability of each such person to pay sums representing services charges, and for such purposes may set a standard as a basis of judgment of ability to pay under Section 5-116 of this Act. The Department shall by rule make provisions for unusual and exceptional circumstances in the application of such standard. The Department may issue to any person liable under this Act a statement of amount due as treatment charges requiring him to pay monthly, quarterly or otherwise as may be arranged, an amount not exceeding that required under this Act, plus fees to which the Department may be entitled under the Act.
Whenever an individual is covered, in part or in whole, under any type of insurance arrangement, private or public for services provided by the Department, the proceeds from such insurance shall be considered as part of the individual's ability to pay, notwithstanding that the insurance contract was entered into by a person other than the individual or notwithstanding that the premiums for such insurance were paid for by a person other than the individual.
405 ILCS 5/5-108