Illinois currently allows the sale of cannabis to both registered medical cannabis patients as well as adult-use cannabis consumers.
To shop, Illinois requires medical patients to be at least 18 years of age with a valid Illinois Medical Marijuana card and valid government issued photo ID. Illinois doesn't offer any reciprocity, so only in-state medical patients can shop the medical menu. Out-of-state medical patients must shop as adult-use.
Adult-use cannabis consumers must be 21 years of age with a valid government issued photo ID (in-state and out-of-state).
Guests are also allowed to accompany purchasers as long as they are over the age of 21 and have a valid ID
For curbside, there may be other passengers in the vehicle of any age, and they are not required to provide identification. Only the purchaser must provide their valid medical card and ID.
See also:
How do I obtain an Illinois medical marijuana card?
What information is required to shop in Illinois?