Even if marijuana is legal in your state, the Office of Personnel Management would like to remind federal employees that you could still lose your job if you get caught with it:
Federal law on marijuana remains unchanged. Marijuana is categorized as a controlled substance under Schedule I of the Controlled Substance Act. Thus knowing or intentional marijuana possession is illegal, even if an individual has no intent to manufacture, distribute, or dispense marijuana. In addition, Executive Order 12564, Drug-Free Federal Workplace, mandates that (a) Federal employees are required to refrain from the use of illegal drugs; (b) the use of illegal drugs by Federal employees, whether on or off duty, is contrary to the efficiency of the service; and (c) persons who use illegal drugs are not suitable for Federal employment.