Steroids, since several years ago have been classified as a Schedule III drug.
In the United States, drugs are classified into 5 schedules: Schedule I, II, III, IV, and V. It is ranked based on three considerations: potential for abuse, accepted medical use, and potential for addiction. The highest schedule, is Schedule I, while the lowest is Schedule V.
A schedule III drug, like steroids, have medium potential for addiction, can be used for medical use, and can cause severe mental addiction and moderate physical addiction.