| Code | Display | Comments |
| I | Schedule I | | Includes drugs that have a high potential for abuse, no currently accepted medical use in the United States and a lack of accepted safety for use under medical supervision. |
| II | Schedule II | | Includes drugs having currently accepted medical use in the United States and a high abuse potential, with severe psychological or physical dependence liability. |
| III | Schedule III | | Includes drugs having an abuse potential less than that of drugs listed in Schedules I and II. All CS III drugs have a currently accepted medical use in the United States. |
| IV | Schedule IV | | Includes drugs having a lesser potential for abuse than those listed in Schedule III. CS IV drugs have a currently accepted medical use in the United States. |
| V | Schedule V | | Includes drugs having low abuse potential and limited physical or psychological dependence relative to those listed in IV and have an accepted medical use in the United States. |
| VI | Schedule VI | | State defined |
