According to Illinois Secretary of State, "Illinois' mandatory insurance law is one of the most significant consumer protection measures now on the books.
Mandatory Insurance Verification
Complying with the Law
You are in compliance with the mandatory insurance law if you have vehicle liability insurance in the following minimum amounts:
$25,000 - injury or death of one person in an accident
$50,000 - injury or death of more than one person in an accident
$20,000 - damage to property of another person
You must always carry your insurance card in your vehicle and show it upon request by any law enforcement officer. Your insurance company will send you an insurance card, usually when your insurance policy is issued or renewed.
Your signature on the Vehicle Renewal Registration Application affirms that your vehicle will be properly insured throughout the registration period."