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Domain Guides5 min read

Understanding Controlled Substance Schedules

A clear breakdown of DEA controlled substance schedules for the PTCE.

January 8, 2026

Why Schedules Matter

Controlled substance scheduling is a core Federal Requirements topic. The DEA classifies controlled substances into five schedules based on accepted medical use and abuse potential.

Schedule I

No currently accepted medical use in the United States and high abuse potential. Not dispensed in typical pharmacy settings. Heroin and LSD are commonly cited examples.

Schedule II

High abuse potential but accepted medical uses. Includes oxycodone, morphine, methylphenidate (Ritalin), and amphetamine salts (Adderall). Schedule II prescriptions generally cannot be refilled and require a new prescription each time.

Schedule III

Moderate abuse potential. Testosterone and certain combination products with limited codeine amounts fall here. Prescriptions can typically be refilled up to five times within six months of the date written.

Schedule IV

Lower abuse potential. Benzodiazepines like alprazolam (Xanax) and diazepam (Valium) are common examples, along with zolpidem (Ambien). Refill rules match Schedule III.

Schedule V

Lowest abuse potential among controlled substances. Cough preparations with limited codeine amounts are a typical example.

Key Exam Points

Focus on which common medications fall into which schedule, refill limitations, and general storage and record-keeping requirements. Controlled substance questions appear frequently, so invest extra time here if practice tests reveal a weak area.

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