Marijuana is legal for medical purposes in some US states, including Maryland. If you would like to know more information about it, read further and check the answers to the frequently asked questions about this subject matter. Q: When was marijuana legalized in Maryland? A: House Bill 881 was approved on April 8, 2014, by the Maryland House and the Maryland Senate, getting 125-11 and 44-2 votes, respectively. It was signed by the governor on April 14, 2014, and made effective starting June ...