Twenty states and the District of Columbia, have medical marijuana programs. Patients can either buy or grow marijuana for things like pain relief. The General Assembly took a first, cautious stab at creating a medical marijuana program last year. Marijuana was to be made available through academic medical centers. But, none of the centers in Maryland signed up to participate. Legislators decided this past session to allow certified doctors to write prescriptions for medical marijuana that can be bought from licensed growers and dispensaries.