The History, Science, and Politics Behind Marijuana’s Schedule I Status

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For a state-licensed medical marijuana business, the April 28, 2026 rule does more than place its medical marijuana in Schedule III, a category whose usual legal tests recognize accepted medical use: federal registration lets the business lawfully manufacture, distribute or dispense marijuana for medical purposes, subject to its state-license limits and federal requirements. Recreational manufacture, distribution and possession remain illegal under federal law, and would stay illegal even after a complete move to Schedule III.

The current answer is no longer one schedule for all marijuana

Marijuana is still a federally controlled substance, but it no longer sits in a single category. Congress placed it in Schedule I in 1970, the federal drug-control category with the strictest restrictions. Under a rule that took effect April 28, 2026, drugs containing marijuana that the Food and Drug Administration has approved and medical marijuana covered by a state license are in Schedule III, a less restrictive category. All other marijuana stays in Schedule I.

The Justice Department and Drug Enforcement Administration issued a final rule that took effect April 28, 2026. It puts Food and Drug Administration (FDA)-approved drug products containing marijuana and marijuana covered by a state medical marijuana license in Schedule III. Schedule I still covers marijuana crops and other marijuana that is neither in an FDA-approved product nor under such a license. So it is no longer accurate to say all marijuana is in Schedule I, and it is also wrong to say marijuana has been federally legalized.

States cannot change federal law, and the Constitution’s Supremacy Clause gives federal law precedence over conflicting state laws. As the Congressional Research Service explains, marijuana remains a controlled substance, and unauthorized activities involving it remain federal crimes even in states that permit them. State permission is therefore a separate question from permission under the federal Controlled Substances Act, the law that organizes federal drug controls.

Not every cannabis product is a controlled substance. Hemp falls outside the Controlled Substances Act’s controls, with federal law defining it as cannabis containing no more than 0.3 percent of the psychoactive compound delta-9-tetrahydrocannabinol, or THC. Under the September 2, 2026 law, parts of the new hemp definition take effect December 11, 2026. Other provisions take effect November 12, 2026, including one that removes hemp-derived cannabinoid products containing certain synthetic cannabinoids, meaning ones a cannabis plant cannot produce naturally, from the definition of hemp. From that date, products that fit the exclusion are to be classified as marijuana under the Controlled Substances Act.

What the schedule number actually means

One distinction in the usual legal tests is medical use: Schedule III requires an accepted medical use in U.S. treatment, while Schedule I requires “no currently accepted medical use”.

Schedule I requires a high potential for abuse, no “currently accepted medical use” in treatment in the United States, and a lack of accepted safety for use under medical supervision. Schedule III requires lower abuse potential than drugs in Schedules I and II, an accepted medical use, and abuse that may cause moderate or low physical dependence or high psychological dependence. These are legal criteria for placing a substance under controls, rather than a single score for how much harm it can cause.

Both Schedule I and Schedule II can include substances with high abuse potential, but Schedule II recognizes accepted medical use. A lower number therefore cannot, on its own, establish that one drug is more dangerous than every drug in a higher-numbered schedule. Likewise, moving to Schedule III recognizes a different combination of abuse potential and medical use, rather than declaring a substance harmless.

In a regular scheduling decision, the Attorney General, who holds the authority to change a drug’s schedule without an act of Congress, must weigh abuse potential, drug effects, current scientific knowledge, the history and scale of abuse, public-health risks, dependence and whether the substance is a precursor of an already controlled drug. Being a plant is not an answer to those questions: the decision concerns what the substance does and how it is used, not whether its origin sounds natural.

Congress made the original choice in 1970

Federal restrictions preceded the schedules: Congress enacted the Marihuana Tax Act in 1937. That law imposed taxes and registration and reporting requirements on growers, sellers and buyers, a system the Congressional Research Service describes as having the effect of prohibition even without prohibiting marijuana outright.

Congress placed marijuana in Schedule I when it enacted the Controlled Substances Act in 1970. In advice dated August 14, 1970, Assistant Secretary of Health Roger Egeberg recommended retaining marijuana in the draft bill’s Schedule I until ongoing studies were completed, citing gaps in knowledge of the plant and its active drug. In Egeberg’s account, the placement rested on what was not yet known about the drug, not on a settled scientific finding.

In 1972, a national commission created by Congress under the Controlled Substances Act recommended removing criminal penalties for private personal use and possession, while keeping production and distribution criminal, and President Richard Nixon rejected the idea.

The National Commission on Marihuana and Drug Abuse issued its first report, Marihuana: A Signal of Misunderstanding, in March 1972. The commission recommended decriminalizing possession for personal use at both federal and state levels, while keeping production and commercial distribution criminal and allowing confiscation of marijuana in public.

After receiving the commission’s report in March 1972, Nixon said he disagreed with its recommendation and opposed legalizing marijuana’s sale, possession and use. The commission’s study did not settle the policy: officials still had to choose what conduct the law would punish.

Why the earlier medical-use test kept marijuana in Schedule I

In a decision issued July 19, 2016 and published August 12, 2016, the Drug Enforcement Administration, or DEA, refused to begin proceedings to reschedule marijuana. DEA concluded that marijuana continued to have high abuse potential and no “currently accepted medical use” under its five-part test. The Department of Health and Human Services, or HHS, which supplied the scientific and medical evaluation DEA requested, also concluded that marijuana lacked an acceptable level of safety even under medical supervision.

The five-part test required known and reproducible chemistry, adequate safety studies, adequate well-controlled studies demonstrating effectiveness, acceptance by qualified experts, and widely available scientific evidence. DEA said marijuana did not meet any of those requirements. The question was whether the evidence met a particular federal test, not whether patients reported relief or a state allowed medical use.

HHS reopened the question with a different assessment

In an August 29, 2023 letter, HHS Assistant Secretary for Health Rachel Levine recommended that DEA move marijuana to Schedule III. HHS found abuse potential below drugs in Schedules I and II and the possibility of moderate or low physical dependence or high psychological dependence. That finding was compatible with continuing federal controls, even as it challenged the basis for the most restrictive category.

HHS used an alternative medical-use test asking whether licensed practitioners had widespread experience with marijuana under state-authorized programs and whether credible scientific evidence supported such use. It identified accepted medical uses for anorexia related to a medical condition, nausea and vomiting, including chemotherapy-related symptoms, and pain. Under that test, practitioners’ experience in state programs counts alongside scientific evidence, not in place of it.

HHS concluded that marijuana abuse had harmful consequences that appeared less common and less severe than those of some comparison substances, while cautioning that these descriptive analyses could reflect population differences such as age or pre-existing conditions. That comparison does not establish that marijuana is risk-free, or that the same result applies to every person and product.

The HHS medical-use assessment was not a determination of safety and effectiveness under the Food and Drug Administration’s new-drug approval standard. FDA has approved specific medicines including Epidiolex, which contains purified cannabidiol (CBD), Marinol and Syndros, which contain synthetic dronabinol, and Cesamet, which contains synthetic nabilone. Approval of those particular products cannot be transferred to every cannabis product sold under a state medical program.

Under the statute, HHS supplies a written scientific and medical evaluation to the Attorney General, and its recommendations bind the Attorney General on scientific and medical matters. Administrative scheduling authority rests with the Attorney General, who generally delegates it to DEA, while Congress can change schedules directly through legislation. An HHS recommendation is therefore one input into a legal decision; it does not change the schedule by itself.

What has changed, and what is still pending

In a May 21, 2024 notice, the Justice Department proposed a broader change: transferring marijuana from Schedule I to Schedule III. The medical rule that took effect in April 2026 says it was issued to carry out U.S. obligations under the Single Convention on Narcotic Drugs, an international drug-control treaty. The law lets the Attorney General schedule a substance to meet treaty obligations without the findings and procedures that regular scheduling requires. That rule limited the change to FDA-approved products and marijuana under state medical licenses. The 2024 proposal covers marijuana generally and is still pending.

On September 29, 2026, DEA’s chief administrative law judge, Derek Julius, stayed the case pending resolution of the motion. A hearing ran from June 29 to July 15, and three interested parties then asked the judge to admit a Government Accountability Office report, which found that DEA lacks policies identifying staff roles, responsibilities and procedures for drug scheduling. The September 29, 2026 order required the government to respond to that motion by October 13, 2026, and left unresolved whether to admit the report or allow additional briefs. That response deadline is a procedural step, not a promised date for all marijuana to change schedules.

For the broader record, follow the DEA marijuana-rescheduling index and look for DEA docket 1362 and hearing docket 26-96. The October 13 response is the government’s answer to that motion, not an invitation for the general public to file new comments.

For state-licensed medical manufacturers, distributors and dispensers, the April medical rule creates a DEA-registration pathway. Applicants who filed within 60 days of the rule’s April 28, 2026 publication in the Federal Register may operate under their state licenses while DEA reviews their applications. California’s Department of Cannabis Control reports that DEA continues accepting applications, but submissions after June 26, 2026 are not eligible for expedited processing. The rule also says a state-authorized medical marijuana certification is sufficient to permit dispensing to the patient, provided the document contains the user’s name and address, is dated and signed on issuance, and identifies the issuing practitioner. That provision is about dispensing in state medical programs; unauthorized activities involving marijuana remain federal crimes.

Section 280E of the tax code denies covered businesses deductions or credits for business expenses when their business consists of trafficking in prohibited Schedule I or II substances. In the final rule, the Acting Attorney General says state licensees will no longer be subject to that disallowance. The rule adds that it is not a determination of federal tax liability and that qualifying licensees should consult tax counsel about how Section 280E applies to them.

Schedule III research-registration requirements are generally less stringent than Schedule I requirements, although marijuana-specific procedures from the 2022 Medical Marijuana and Cannabidiol Research Expansion Act continue to apply.

Even if all marijuana moved to Schedule III, recreational manufacture, distribution and possession would remain illegal under federal law, regardless of state permission.

The April medical rule was challenged in the D.C. Circuit in SAM, Inc. and National Drug and Alcohol Screening Association, Inc. v. United States Department of Justice, consolidated with other petitions. Smart Approaches to Marijuana, or SAM, says it is fighting rescheduling in court. In its September 9, 2026 order, the D.C. Circuit denied a temporary stay and required the parties to propose briefing formats within 30 days. That order did not decide the rule’s validity on the merits, and its refusal to pause the medical rule is separate from the administrative judge’s later pause of the broader proceeding.

The political choice extends beyond a schedule number

NORML, an organization advocating marijuana-law reform, argues that cannabis should be removed from the Controlled Substances Act entirely so states can make their own regulatory choices. Its case is that rescheduling alone leaves state markets subject to federal requirements that states cannot override. NORML also points out that marijuana-specific statutory criminal penalties do not automatically change with rescheduling and would require congressional action.

On August 29, 2025, Representatives Jerrold Nadler, Dina Titus, Ilhan Omar and Nydia Velázquez reintroduced the Marijuana Opportunity Reinvestment and Expungement Act, or MORE Act, as a proposal for federal decriminalization. Nadler’s stated goals include expunging marijuana convictions, facilitating resentencing and reinvesting in communities harmed by past drug enforcement. The bill, H.R. 5068, is still listed as introduced; it was referred to House Agriculture subcommittees on January 13, 2026.

SAM opposes Schedule III, arguing that the industry tax break would send a misleading message that high-potency marijuana is medicine. SAM argues that the medical route relies on weak state rules for certifications, labeling and packaging and could promote more marketing and commercialization.

In its comments on the proposed rule, SAM criticized the departure from DEA’s five-part medical-use test and alleged that HHS gave insufficient weight to risks involving adolescent use, driving and respiratory harms. SAM points to a November 2025 JAMA review by Hsu and colleagues that found randomized trials did not support cannabis or cannabinoids for most conditions for which they were promoted.

When the next federal decision arrives, check which marijuana it covers, what conduct it authorizes and which restrictions it leaves to Congress or the states.