Cannabis in Massachusetts is legal for both medical and adult use.

Massachusetts legalized the medical use of cannabis in the 2012 November election cycle,. The law took effect January 1, 2013.  The state legalized the adult use of cannabis in the 2016 November election cycle. As a result, cannabis became legal for adults to grow and possess in Massachusetts on December 15, 2016.

Within Massachusetts adult use framework, adults 21+ may possess up to 1 ounce of marijuana, except that not more than 5 grams of marijuana may be in the form of marijuana concentrate. Adults may possess up to 10 ounces and up to 6 plants within their home. Within the medical framework, patients may possess a 60 day supply (10 ounces unless given special medical permission) and up to 12 home plants.