Marijuana decriminalization in D.C. means that…
Although it remains a crime under federal law, it is not a criminal offense in D.C. for adults 21 years of age or older to: 
  • Possess two ounces or less of marijuana
  • Grow within their primary residence up to six marijuana plants, no more than three of which are mature
  • Transfer one ounce or less of marijuana to another person as long as: (1) no money, goods, or services are exchanged; and (2) the recipient is 21 years of age or older
  • Possess marijuana-related drug paraphernalia that is associated with possession or use that is not criminal under D.C. law 
  • Consume marijuana on private property
Nonetheless, it remains a crime under D.C. law for anyone to: 
  • Possess more than two ounces of marijuana
  • Smoke or consume marijuana on public space (parks, streets, alleys, sidewalks) or anywhere to which the public is invited – including restaurants and bars (even hookah bars and cigar lounges)
  • Sell any amount of marijuana to another person or buy any amount from another person
  • Operate a vehicle or boat under the influence of marijuana
  • Possess any amount of marijuana if under the age of 21 
All of the rules above govern what the D.C. police will arrest you for. Federal law enforcement officers still may arrest anyone in the District for possession of any amount of marijuana. You still cannot have marijuana on federal land (which includes Rock Creek Park, the National Mall, and area around federal buildings) or on the Metro system. Marijuana remains prohibited in public housing, even in your own apartment.