This report updates and extends estimates of the number of users, retail expenditures, and amount consumed from 2006 to 2016 for cocaine (including crack), heroin, marijuana, and methamphetamine in the United States. The authors find that people spent about $150 billion on these drugs in 2016. The authors’ best estimates for 2016 suggest that the marijuana market was roughly the size of the cocaine and methamphetamine markets combined.