Understanding Drug Classifications: Are Opioids Schedule 1 or 2?

October 11, 2025 •

2 min read

The classification of controlled substances under the federal Controlled Substances Act (CSA) is based on a drug's accepted medical use, abuse potential, and dependency risk. The determination of whether are opioids schedule 1 or 2 depends on these factors, with some falling into different categories entirely.

Quick Summary

The classification of opioids varies under the Controlled Substances Act, with some, like heroin, categorized as Schedule I due to no medical use, while most prescription opioids, like fentanyl and oxycodone, are Schedule II with high abuse potential and accepted medical uses. Other opioids may fall into Schedules III through V.

Key Points

Not a single schedule: Opioids are classified into different schedules, including Schedule I, Schedule II, and sometimes others, depending on the specific substance and its properties.
Schedule I: Heroin is the primary example of an opioid classified as Schedule I, meaning it has a high potential for abuse and no accepted medical use.
Schedule II: The majority of commonly prescribed opioids, such as fentanyl, oxycodone, and morphine, are classified as Schedule II because they have a high potential for abuse but also have accepted medical uses.
Prescription Rules: The difference in scheduling determines prescribing rules. Schedule I drugs cannot be prescribed, whereas Schedule II drugs require a new prescription for each fill and have strict regulations.
Other schedules: Some opioids, like codeine in certain preparations, can be found in Schedules III or V, which have lower abuse potentials than Schedule I or II.
Regulatory Basis: The Controlled Substances Act (CSA) and the Drug Enforcement Administration (DEA) govern the classification and regulation of all controlled substances in the US.

The Framework of the Controlled Substances Act

The Controlled Substances Act (CSA) of 1970 categorizes substances into five schedules based on their potential for abuse, accepted medical use, and risk of dependence. Schedule I has the highest restrictions, while Schedule V has the fewest. The classification can change based on new evidence. This system helps determine whether opioids are Schedule 1 or 2, or another schedule.

Schedule I: High Potential for Abuse with No Medical Use

Schedule I substances have a high potential for abuse, no accepted medical use in the U.S., and lack accepted safety for medical use. They are the most dangerous and cannot be prescribed. Heroin is a Schedule I opioid due to its high abuse potential and lack of medical application.

Schedule II: High Potential for Abuse with Accepted Medical Use

Schedule II substances have a high potential for abuse but do have accepted medical uses in the U.S.. Abuse can lead to severe dependence. Regulations for Schedule II drugs are strict, requiring a new prescription for each fill. Most commonly prescribed opioids are in this category, including:

Fentanyl: Used for severe pain.
Oxycodone: Found in OxyContin® and Percocet®.
Morphine: Treats moderate to severe pain.
Hydrocodone: In combination products like Vicodin®.
Methadone: Used for pain and opioid addiction treatment.
Hydromorphone: Marketed as Dilaudid®.

These drugs are vital for pain management but require strict oversight.

Opioids in Other Drug Schedules (III-V)

Some opioids are in less restrictive schedules due to lower abuse potential or concentration.

Schedule III

These have a lower abuse potential than Schedule I and II, with moderate or low physical dependence risk or high psychological dependence risk. Examples include Tylenol with Codeine® and buprenorphine.

Schedule V

These have a low abuse potential relative to Schedule IV and are often in cough or antidiarrheal medications, such as cough preparations with small amounts of codeine.

Comparison Table: Schedule I vs. Schedule II Opioids


Feature	Schedule I Opioids	Schedule II Opioids
Medical Use	No currently accepted medical use in the United States.	Has currently accepted medical uses in treatment.
Abuse Potential	High potential for abuse.	High potential for abuse.
Dependence Risk	Severe psychological or physical dependence.	Severe psychological or physical dependence.
Prescription Status	Cannot be prescribed.	May be prescribed by a physician.
Refills	Not applicable; no medical prescription is allowed.	No refills are permitted. A new prescription is required for each fill.
Example Opioid	Heroin.	Fentanyl, Oxycodone, Morphine, Hydrocodone.

Conclusion: The Nuance of Opioid Scheduling

Opioids can be Schedule 1, 2, or other schedules. Classification depends on medical use, abuse potential, and dependence risk under the CSA. Accepted medical use in the U.S. differentiates Schedule I (like heroin) from Schedule II (like fentanyl and oxycodone). Understanding these classifications is crucial for healthcare professionals and patients. The DEA website provides official information. This system balances medical benefits with abuse risks.

Frequently Asked Questions

The primary difference lies in their accepted medical use. Schedule I opioids have no currently accepted medical use in the United States, while Schedule II opioids have accepted medical uses, despite both having a high potential for abuse.

Heroin is classified as a Schedule I opioid. This classification is because it has a high potential for abuse and no accepted medical use for treatment in the United States.

Fentanyl and oxycodone are classified as Schedule II because, although they have a high potential for abuse and dependence, they also have accepted medical uses for treating severe pain.

No, Schedule II controlled substances cannot be refilled. A new, written prescription from a licensed healthcare provider is required for every fill.

Less potent opioids or those containing limited quantities of certain narcotics, such as cough syrup with codeine, can be classified in Schedules III or V, which have a lower potential for abuse.

The Controlled Substances Act (CSA) is a federal law in the United States that regulates the manufacture, possession, and distribution of controlled substances, categorizing them into five schedules based on their potential for abuse and medical use.

The Drug Enforcement Administration (DEA), in consultation with the Department of Health and Human Services (HHS), determines the schedule of a controlled substance based on the criteria outlined in the CSA.