United States
Hong KongDEA schedules
There are five schedules. Schedule I has no accepted medical use in the United States; II to V descend in abuse potential, and the handling rules tighten as the schedule number falls.
The backbone of the Federal Requirements domain. Almost every controlled-substance question depends on knowing which schedule you are in.
The five
| Schedule | Abuse potential | Accepted medical use |
|---|---|---|
| I | High | None in the United States |
| II | High | Yes, with severe restrictions |
| III | Less than I and II | Yes |
| IV | Low relative to III | Yes |
| V | Low relative to IV | Yes |
The schedules are defined at 21 CFR 1308, and the ordering is the logic behind every rule that follows.
What changes as you move down
- Refills: prohibited entirely for Schedule II; permitted within limits for III to V
- Ordering: Schedules I and II require DEA Form 222 or its electronic equivalent
- Transfer and emergency supply rules loosen
- Recordkeeping remains strict throughout
Questions rarely ask what Schedule IV is. They ask whether something permitted for Schedule III is also permitted for Schedule II, because that is where candidates blur the rules together. Learn the differences between adjacent schedules rather than the schedules in isolation.
Schedule II is the one to know cold
No refills, ever. The refilling of a prescription for a controlled substance listed in Schedule II is prohibited at 21 CFR 1306.12.
A prescriber writing refills on a Schedule II prescription does not create an authority to dispense them. The original fill is all that may be dispensed.
Schedules III and IV
A prescription may not be filled or refilled more than six months after the date it was issued, nor refilled more than five times, under 21 CFR 1306.22.
Both conditions bind. Five refills inside six months is the ceiling and whichever limit arrives first ends the prescription.
How to remember it
Not as five lists of drugs. As one ordered scale with a small number of rules attached at specific points, most of them at the II and III boundary.
Common questions
How many DEA schedules are there?
Five, ordered by abuse potential and accepted medical use.
What defines Schedule I?
High abuse potential and no accepted medical use in the United States.
Can Schedule II prescriptions be refilled?
No. Refilling is prohibited at 21 CFR 1306.12.
What are the Schedule III and IV limits?
Not filled or refilled more than six months after issue, and not refilled more than five times.
What does the exam actually test?
The boundaries between adjacent schedules, particularly II against III.