The 2nd criteria for a drug to be classified as a Schedule I controlled substance under the Controlled Substances Act states "The drug or other substance has no currently accepted medical use in treatment in the United States."
There are currently 23 states along with Washington D.C. that have legalized marijuana for medicinal purposes upon recommendation from a physician.
If primary care physicians in the United States are prescribing marijuana to patients for medical treatment, then marijuana does not meet the requirements for a Schedule I substance.
Marijuana should be removed as a Schedule I substance and properly reclassified.