Illinois Marijuana Laws (2026 Update)

Marijuana is legal for both medical and recreational use in the State of Illinois. Under the Cannabis Regulation and Tax Act, adult persons aged 21 years of age and older can legally possess and use cannabis for personal consumption as of January 1, 2020; however, federal law prohibits the use and possession of marijuana even though state law in Illinois allows such activities.

As it pertains to adults aged 21 and older in Illinois, the law allows for the possession of 30 grams of marijuana in flower form, 500 milligrams of THC in the form of cannabis-infused products, and 5 grams of THC through the use of concentrates. The amount of cannabis one possesses in excess of these limits will determine the level of criminality (felony or misdemeanor) of possessing an amount of marijuana in excess of that allowed by Illinois law.

If you have registered as a medical marijuana user, then you are permitted to grow a maximum of 5 marijuana plants at home, provided they are kept indoors and secured in a locked and fully enclosed area out of view of the general public.

While it is legal to use or possess marijuana in Illinois within stated limits, there are still penalties for violating local state laws. If you possess cannabis beyond your allowable limit by state laws, you could face criminal charges, such as a misdemeanor or felony, based on the total amount of cannabis you possess and whether you have any prior convictions.

Only physicians that are licensed and authorized by the Illinois Department of Public Health (IDPH) can certify patients for medical cannabis use as part of the IDPH’s Medical Cannabis Patient Registry Program. Medical marijuana patients can receive a certificate from their physician certifying that they have an approved medical condition and apply to the Illinois Medical Cannabis Patient Program for their medical marijuana card.