Controlled Substances Act
Definition: The Controlled Substances Act (CSA) is the 1970 US federal law that regulates drugs by sorting them into five schedules based on medical use and potential for abuse. Marijuana has been in Schedule I, the most restrictive category, since the law took effect. In 2026, the federal government began moving some medical marijuana to Schedule III.
What Are the Five Drug Schedules?
| Schedule | What it means | Examples |
|---|---|---|
| I | High abuse potential, no accepted medical use | Heroin, LSD, marijuana (most) |
| II | High abuse potential, accepted medical use | Oxycodone, fentanyl, cocaine |
| III | Moderate to low dependence risk | Ketamine, anabolic steroids, dronabinol (Marinol) |
| IV | Low abuse potential | Xanax, Valium |
| V | Lowest abuse potential | Low-dose codeine cough syrups |
Why Is Marijuana in Schedule I?
Congress placed marijuana in Schedule I in 1970 as a temporary measure while a national commission studied it. The Shafer Commission recommended decriminalizing personal possession in 1972, but the classification stayed. The DEA, created in 1973, enforces the CSA, and the Department of Health and Human Services provides the medical review needed to change a drug’s schedule.
Has Marijuana Been Rescheduled?
Partly. In 2023, HHS recommended moving marijuana to Schedule III, and the DEA proposed that change in May 2024. In April 2026, the DEA moved marijuana in FDA-approved drug products and marijuana handled under state medical cannabis licenses to Schedule III. All other marijuana, including most adult-use cannabis, remains in Schedule I while a broader rescheduling hearing, held in mid-2026, awaits a final decision. Hemp was removed from the CSA entirely by the 2018 Farm Bill.
What Would Schedule III Change?
Schedule III wouldn’t legalize recreational cannabis federally. It would recognize accepted medical use, ease barriers to research, and let state-licensed businesses deduct normal business expenses that federal tax law currently bars for Schedule I and II trafficking.
Related terms: Cole Memo, Rohrabacher-Farr Amendment, FDA, Hemp
Sources: DEA: Marijuana Rescheduling Regulatory Actions; Morgan Lewis: Post-DEA Hearing, Broader Marijuana Rescheduling Questions Remain (2026).
Last reviewed October 2026. This entry is for general education and isn’t legal advice.
