625 ILCS 5/11-500
For the purposes of interpreting Sections 6-206.1 and 6-208.1 of this Code, "first offender" shall mean any person who has not had a previous conviction or court assigned supervision for violating Section 11-501, or a similar provision of a local ordinance, or a conviction in any other state for a violation of driving while under the influence or a similar offense where the cause of action is the same or substantially similar to this Code or similar offenses committed on a military installation, or any person who has not had a driver's license suspension pursuant to paragraph 6 of subsection (a) of Section 6-206 as the result of refusal of chemical testing in another state, or any person who has not had a driver's license suspension or revocation for violating Section 11-501.1 within 5 years prior to the date of the current offense, except in cases where the driver submitted to chemical testing resulting in an alcohol concentration of 0.08 or more, or any amount of a drug, substance, or compound in such person's blood, other bodily substance, or urine resulting from the unlawful use or consumption of cannabis listed in the Cannabis Control Act, a controlled substance listed in the Illinois Controlled Substances Act, or an intoxicating compound listed in the Use of Intoxicating Compounds Act, or methamphetamine as listed in the Methamphetamine Control and Community Protection Act and was subsequently found not guilty of violating Section 11-501, or a similar provision of a local ordinance.
625 ILCS 5/11-500