Governor Bruce Rauner signed Illinois Senate Bill 10 on Thursday.
It now gives post-traumatic stress disorder patients access to medical marijuana and extends the state’s pilot program until July 2020.
It also opens the program to those with a terminal illness with a diagnosis of six months or less.
And it will regulate how doctors approve patients for other debilitating medical conditions.
State Representative Lou Lang of Skokie says the extension and technical changes are crucial to gauging the program's success.
Medical marijuana advocates and experts call it a turning point that gives patients guaranteed access and provides confidence to those legally selling and cultivating the drug.
- WNIJ's Katie Finlon and The Associated Press contributed to this report.