Amends the Illinois Antitrust Act. Provides that documentary material, transcripts of oral testimony, or answers to interrogatories obtained in an investigation of a violation of the Act may be used by the Attorney General in any administrative or judicial action or proceeding. Provides that information voluntarily produced to the Attorney General for purposes of an investigation of a violation of the Act or information provided to the Attorney General under a notice requirement shall be treated as if produced pursuant to a subpoena for purposes of maintaining the confidentiality of such information. Provides that health care facilities that are party to a covered transaction shall provide notice of such transaction to the Attorney General no later than 60 days prior to the transaction closing or effective date of the transaction. Provides that any health care facility that fails to comply with the notice requirement is subject to a civil penalty of not more than $500 per day for each day during which the health care facility is in violation of the requirement. When the Attorney General has reason to believe that a health care facility has engaged in or is engaging in a covered transaction without complying with the notice requirement, allows the Attorney General to apply for and obtain a temporary restraining order or injunction prohibiting the health care facility from continuing its noncompliance or doing any act in furtherance thereof. Makes a conforming change in the State Finance Act. Effective January 1, 2024.