As of 2016, state-licensed dispensaries in 32 states sell marijuana to adults with a medical need for marijuana, while two states, Washington and Colorado, have state-licensed dispensaries sell marijuana to adults for medical or recreational use. Federal law prohibits the possession, sale or cultivation of marijuana. However, an amendment to the Consolidated and Further Continuing Appropriations Act of 2015, signed by President Barack Obama on Dec. 16, 2014, prohibits federal interference with the implementation of states' medical marijuana laws.
The Consolidated and Further Continuing Appropriations Act of 2015 does not legalize the possession or sale of marijuana under federal law, nor does it prohibit federal action against shops that sell marijuana for recreational use. In Washington and Colorado, dispensaries obtain licenses from the state to sell marijuana to people 21 years of age or older, regardless of medical necessity.
Other states have established legal regimes that specify rules and regulations on how people with a medical need for marijuana can prove this need. These states establish guidelines about who can certify medical necessity and for what reasons they may do so. Typically, a person is issued a document, such as the Medical Marijuana Identification Card in California, which they present at a dispensary that sells marijuana or certain state-approved products containing marijuana, such as smokable hash or edible products.