Amendment 20 to the state constitution was approved by 54% of voters on November 7, 2000. Effective June 1, 2001, the law authorizes individuals diagnosed by a physician as having a debilitating condition to use cannabis in accordance with that doctor's recommendation. Qualifying conditions include cancer, HIV/AIDS, glaucoma, cachexia, severe and chronic pain, epilepsy and other disorders characterized by seizures, multiple sclerosis and other disorders characterized by persistent muscle spasms, central nervous system disorders, and nausea. The Colorado Board of Health may add additional conditions to the list upon approval.
The constitutional amendment states that patients and caregivers may possess no more than two ounces of usable marijuana at any time and they may cultivate up to six plants.
Colorado's medical cannabis law establishes a confidential patient registry for qualifying patients and designated caregivers. An affirmative defense of medical necessity is available to those individuals who choose not to register with the state or who are in possession of amounts greater than those authorized under the law.
Caregivers must be 18 years old or older. Patients may only have one caregiver at a time and a patient who has a designated caregiver may not be designated as a caregiver for another qualifying patient. Caregivers may assist no more than five patients at a time.
On June 7, 2010, HB 1284 established guidelines and protocols for the licensing of dispensing centers. Dispensing centers must be licensed by the state and local agencies and comply with all zoning codes. For example, dispensaries must be no closer than 1,000 feet to a school or daycare facility. There is a licensing fee and 70% of the cannabis sold in a facility must be grown by that facility. In order for their applications to be approved, potential dispensary owners must undergo background checks by the state. Starting July 1, 2010, HB 1284 places a moratorium on new dispensaries statewide. Local agencies may ban dispensaries in their communities. In the event a ban is enacted, caregivers are still permitted to care for up to five patients.
Colorado does not grant reciprocity to out of state patients or caregivers.