Drug schedules explained: Schedules I to V

Federal law sorts controlled substances into five schedules. Schedule I is for substances the statute describes as having no currently accepted medical use in treatment in the United States, and Schedules II to V are for substances with accepted medical uses, ordered from the highest to the lowest potential for abuse. A "schedule 2 drug" is therefore a substance that the statute describes as having a high potential for abuse and a currently accepted medical use, where abuse may lead to severe psychological or physical dependence. This page goes through all five schedules. For the wider picture, start with what is a controlled substance.

How do the five schedules compare?

The criteria are in 21 U.S.C. 812(b). Each schedule has three findings. The quotations below are literal.

What is a Schedule I drug?

Schedule I is the most restricted list. The statute says its substances have a high potential for abuse, no currently accepted medical use in treatment in the United States, and a lack of accepted safety under medical supervision. The DEA alphabetical list of August 27, 2026 gives these examples, each with its Controlled Substances Code Number (CSCN): heroin (9200), lysergic acid diethylamide, also called LSD (7315), mescaline (7381) and psilocybin (7437). In the DEA's narcotic column, heroin is marked "Y" and the other three "N."

What is a Schedule II drug?

A Schedule II drug has a high potential for abuse, a currently accepted medical use in the United States (or one with severe restrictions), and abuse that may lead to severe psychological or physical dependence. This is the answer to "what is a schedule 2 drug." Examples from the DEA list:

• Oxycodone (CSCN 9143), morphine (9300), hydromorphone (9150), methadone (9250), hydrocodone (9193) and fentanyl (9801), all marked as narcotics.
• Cocaine (9041), also marked as a narcotic in the list.
• Amphetamine (1100), methamphetamine (1105), methylphenidate (1724) and lisdexamfetamine (1205), none of them marked as a narcotic.

Our pages on Adderall, Vyvanse and fentanyl show how Schedule II status appears in the DEA list and on each product label.

The prescription rules for Schedule II are the strictest of the five. Under 21 CFR 1306.11, a pharmacist may dispense a Schedule II prescription drug only on a written prescription signed by the practitioner, with limited exceptions (emergency oral prescriptions, fax in certain cases, electronic prescriptions under 21 CFR part 1311). In an emergency the pharmacist may act on an oral authorization, limited to the amount needed during the emergency, and the practitioner must deliver a written prescription within 7 days. The rule on repeats is short. Section 1306.12(a) says: "The refilling of a prescription for a controlled substance listed in Schedule II is prohibited."

Section 1306.12(b) lets an individual practitioner issue multiple prescriptions that together cover up to a 90-day supply, if conditions are met. Among them are a legitimate medical purpose, written instructions giving the earliest date each prescription may be filled, and that state law allows it. The regulation adds that it does not mandate or encourage practitioners to do this.

What is a Schedule III drug?

Schedule III substances have less abuse potential than Schedules I and II, an accepted medical use, and may lead to moderate or low physical dependence or high psychological dependence. DEA list examples: ketamine (7285), buprenorphine (9064, marked as a narcotic), testosterone (4000) and butalbital (2100). The list also shows that Schedule III holds some combination products, such as codeine combination products (9804, marked as narcotic). Testosterone, nandrolone and oxandrolone all carry code 4000 in the list, so several anabolic steroids share one number.

What is a Schedule IV drug?

Schedule IV substances have a low potential for abuse relative to Schedule III, an accepted medical use, and may lead to limited physical or psychological dependence relative to Schedule III. DEA list examples: alprazolam (2882), diazepam (2765), lorazepam (2885), clonazepam (2737), zolpidem (2783), tramadol (9752, marked as a narcotic), carisoprodol (8192), modafinil (1680) and phentermine (1640). Many have their own page here, for example Xanax, Ambien and tramadol.

What is a Schedule V drug?

Schedule V has the lowest abuse potential of the five, an accepted medical use, and limited dependence relative to Schedule IV. DEA list examples: pregabalin (2782), lacosamide (2746), brivaracetam (2710) and cenobamate (2720). The list also shows preparations of diphenoxylate and of difenoxin with atropine sulfate in Schedule V, marked as narcotics and printed without a code number. See pregabalin (Lyrica) for a Schedule V drug with a label statement.

Prescription and refill rules for Schedules III, IV and V

Section 1306.21 lets a pharmacist dispense a Schedule III, IV or V prescription drug on a paper prescription signed by a practitioner, a faxed copy, an electronic prescription that meets the rules, or an oral prescription that the pharmacist writes down. An individual practitioner may also administer or dispense these drugs directly in the course of professional practice.

The refill rule is in 21 CFR 1306.22(a): "No prescription for a controlled substance listed in Schedule III or IV shall be filled or refilled more than six months after the date on which such prescription was issued." The same paragraph says a Schedule III or IV prescription may not be refilled more than five times. Section 1306.22 names Schedules III and IV only. We did not find a federal refill cap for Schedule V in the sections we read, so for a Schedule V drug the pharmacist is the person to ask, and state law can add limits.

What schedule is alcohol?

Alcohol has no schedule. The definition of "controlled substance" in 21 U.S.C. 802(6) leaves it out in these words:

The term does not include distilled spirits, wine, malt beverages, or tobacco, as those terms are defined or used in subtitle E of the Internal Revenue Code of 1986.

Alcohol and tobacco are regulated under other laws. Section 802(6) takes no position on their safety. It only places them outside the schedules.

Is marijuana in Schedule I?

The DEA list of August 27, 2026 has several cannabis rows, and we give them as printed. Marihuana (code 7360) is in Schedule I. Marihuana extract (7350) is in Schedule I. "Marijuana, as defined in 21 U.S.C. 802(16), in a U.S. Food and Drug Administration approved product or subject to a state medical marijuana license" (7362) is in Schedule III. "Marijuana extract, as defined in 21 CFR 1308.11(d)(58), in a U.S. Food and Drug Administration approved product or subject to a state medical marijuana license" (7353) is in Schedule III.

The eCFR text of 21 CFR 1308.11 carries a note that links to an amendment published at 91 FR 59698, September 21, 2026. We checked the Federal Register: the document that ends on that page is the DEA final rule placing diphenidine in Schedule I, effective October 21, 2026. It concerns a different substance, so it does not alter the rows above. We did not verify any other cannabis rulemaking and do not describe one.

How does a drug get added or moved?

Two routes start a change. The Attorney General or the Secretary of HHS can begin a proceeding under 21 U.S.C. 811(a), and any interested person can send the DEA Administrator a petition under 21 CFR 1308.43. A petition must contain the proposed rule and a statement of the grounds, including the facts relied on and any relevant medical or scientific evidence. The Administrator tells the petitioner whether it is accepted, and may deny an accepted petition if the grounds do not justify starting proceedings.

Before starting a rulemaking, the Administrator must ask the Secretary of HHS for a scientific and medical evaluation. Under 1308.43(d) and 21 U.S.C. 811(b) the Secretary's recommendations are binding on those matters, so if HHS recommends against control, the DEA cannot control the substance. When the DEA decides to go ahead it publishes a notice of proposed rulemaking in the Federal Register, and no hearing may start until at least 30 days after that notice.

Section 811(c) lists eight factors for the decision:

1. its actual or relative potential for abuse;
2. scientific evidence of its pharmacological effect, if known;
3. the state of current scientific knowledge regarding the drug;
4. its history and current pattern of abuse;
5. the scope, duration, and significance of abuse;
6. what, if any, risk there is to the public health;
7. its psychic or physiological dependence liability;
8. whether the substance is an immediate precursor of a substance already controlled.

A drug's schedule can therefore change over time, and the current DEA list is the reference. Our home page shows the status of each drug on this site against the August 27, 2026 list.

Schedule 1 vs schedule 2

The two differ on one finding above all others. Both are described as having a high potential for abuse. Schedule I has "no currently accepted medical use in treatment in the United States," while Schedule II has a currently accepted medical use or one with severe restrictions. Schedule II prescriptions are governed by 21 CFR 1306.11 and 1306.12, described above.

A note on the UK

US and UK numbers do not match. Fentanyl is Schedule II in the US and Class A, Schedule 2 in the UK, while diazepam is Schedule IV in the US and Class C, Schedule 4 Part 1 in the UK. The UK page explains the British system.

Questions readers ask