Is cannabis legal on a federal level?

In 2018, the Farm Bill redefined the term cannabis as either marijuana, with a THC content exceeding 0.3%, or hemp, with a THC content at or below 0.3%. Hemp was removed from all categories in the Controlled Substance Act, but marijuana remains a Schedule I substance.

Federally, marijuana (along with heroin and LSD) is classified as a Schedule I substance under the Controlled Substances Act. The definition of a Schedule I substance is.....

(A) The drug or other substance has a high potential for abuse

(B) The drug or other substance has no currently accepted medical use in treatment in the United States 

(C) There is a lack of accepted safety for use of the drug or other substance under medical supervision

Therefore, possession, manufacturing, and distribution of marijuana are federally criminalized except for those specifically registered with the Drug Enforcement Agency.