How much cannabis can I possess in Washington, D.C., with an MMJ Card?

In Washington, D.C., registered cardholders can possess up to 8 ounces of medical cannabis within a 30-day rolling period.

Adults 21 and older cultivate up to 6 plants (no more than 3 being mature) in a residence, with or without a valid medical marijuana card.

Anyone who is at least 21 can possess up to 2 ounces of marijuana.