(30 ILCS 540/3-2)
    Sec. 3-2. Beginning July 1, 1993, in any instance where a State official or agency is late in payment of a vendor's bill or invoice for goods or services furnished to the State, as defined in Section 1, properly approved in accordance with rules promulgated under Section 3-3, the State official or agency shall pay interest to the vendor in accordance with the following:
        (1) Any bill, except a bill submitted under Article V
    
of the Illinois Public Aid Code and except as provided under paragraph (1.05) of this Section, approved for payment under this Section must be paid or the payment issued to the payee within 60 days of receipt of a proper bill or invoice. If payment is not issued to the payee within this 60-day period, an interest penalty of 1.0% of any amount approved and unpaid shall be added for each month or fraction thereof after the end of this 60-day period, until final payment is made. Any bill, except a bill for pharmacy or nursing facility services or goods, and except as provided under paragraph (1.05) of this Section, submitted under Article V of the Illinois Public Aid Code approved for payment under this Section must be paid or the payment issued to the payee within 60 days after receipt of a proper bill or invoice, and, if payment is not issued to the payee within this 60-day period, an interest penalty of 2.0% of any amount approved and unpaid shall be added for each month or fraction thereof after the end of this 60-day period, until final payment is made. Any bill for pharmacy or nursing facility services or goods submitted under Article V of the Illinois Public Aid Code, except as provided under paragraph (1.05) of this Section, and approved for payment under this Section must be paid or the payment issued to the payee within 60 days of receipt of a proper bill or invoice. If payment is not issued to the payee within this 60-day period, an interest penalty of 1.0% of any amount approved and unpaid shall be added for each month or fraction thereof after the end of this 60-day period, until final payment is made.
        (1.05) For State fiscal year 2012 and future fiscal
    
years, any bill approved for payment under this Section must be paid or the payment issued to the payee within 90 days of receipt of a proper bill or invoice. If payment is not issued to the payee within this 90-day period, an interest penalty of 1.0% of any amount approved and unpaid shall be added for each month, or 0.033% (one-thirtieth of one percent) of any amount approved and unpaid for each day, after the end of this 90-day period, until final payment is made.
        (1.1) A State agency shall review in a timely manner
    
each bill or invoice after its receipt. If the State agency determines that the bill or invoice contains a defect making it unable to process the payment request, the agency shall notify the vendor requesting payment as soon as possible after discovering the defect pursuant to rules promulgated under Section 3-3; provided, however, that the notice for construction related bills or invoices must be given not later than 30 days after the bill or invoice was first submitted. The notice shall identify the defect and any additional information necessary to correct the defect. If one or more items on a construction related bill or invoice are disapproved, but not the entire bill or invoice, then the portion that is not disapproved shall be paid.
        (2) Where a State official or agency is late in
    
payment of a vendor's bill or invoice properly approved in accordance with this Act, and different late payment terms are not reduced to writing as a contractual agreement, the State official or agency shall automatically pay interest penalties required by this Section amounting to $50 or more to the appropriate vendor. Each agency shall be responsible for determining whether an interest penalty is owed and for paying the interest to the vendor. Except as provided in paragraph (4), an individual interest payment amounting to $5 or less shall not be paid by the State. Interest due to a vendor that amounts to greater than $5 and less than $50 shall not be paid but shall be accrued until all interest due the vendor for all similar warrants exceeds $50, at which time the accrued interest shall be payable and interest will begin accruing again, except that interest accrued as of the end of the fiscal year that does not exceed $50 shall be payable at that time. In the event an individual has paid a vendor for services in advance, the provisions of this Section shall apply until payment is made to that individual.
        (3) The provisions of Public Act 96-1501 reducing the
    
interest rate on pharmacy claims under Article V of the Illinois Public Aid Code to 1.0% per month shall apply to any pharmacy bills for services and goods under Article V of the Illinois Public Aid Code received on or after the date 60 days before January 25, 2011 (the effective date of Public Act 96-1501) except as provided under paragraph (1.05) of this Section.
        (4) Interest amounting to less than $5 shall not be
    
paid by the State, except for claims (i) to the Department of Healthcare and Family Services or the Department of Human Services, (ii) pursuant to Article V of the Illinois Public Aid Code, the Covering ALL KIDS Health Insurance Act, or the Children's Health Insurance Program Act, and (iii) made (A) by pharmacies for prescriptive services or (B) by any federally qualified health center for prescriptive services or any other services.
    Notwithstanding any provision to the contrary, interest may not be paid under this Act when: (1) a Chief Procurement Officer has voided the underlying contract for goods or services under Article 50 of the Illinois Procurement Code; or (2) the Auditor General is conducting a performance or program audit and the Comptroller has held or is holding for review a related contract or vouchers for payment of goods or services in the exercise of duties under Section 9 of the State Comptroller Act. In such event, interest shall not accrue during the pendency of the Auditor General's review.
(Source: P.A. 100-1064, eff. 8-24-18.)