State officials have launched what could be a lengthy process of setting up a system that will allow sick people to legally purchase Illinois-grown marijuana for medicinal reasons.

Officials in at least four state agencies are beginning to meet to discuss what role they’ll have in drafting rules that will govern the state’s new marijuana law with an eye on taking a final version to lawmakers by May 2014.

Illinois this summer became the 20th state to legalize the use of marijuana for medical purposes. The Compassionate Use of Medical Cannabis Pilot Program Act permits the use of marijuana by patients with serious medical conditions, including cancer, glaucoma, HIV/AIDS, hepatitis C, amyotrophic lateral sclerosis, Crohn’s disease, multiple sclerosis, Lupus and a number of other serious and painful ailments.