Cannabis Law and Access in United States

Forty-seven states. That's how many US jurisdictions have enacted some form of cannabis-related legislation , medical, adult-use, or both , whilst the federal government still classifies cannabis as a Schedule I controlled substance under the Controlled Substances Act 1970. The gap between those two realities is where things get genuinely complicated, and honestly, it's the kind of regulatory knot I find myself explaining to Australians fairly often.

A quick note before we go further: this article describes US law. It is not Australian law, and nothing here is relevant to accessing cannabis in Australia except as a point of contrast. Australian readers should refer to the TGA's frameworks , the Special Access Scheme and the Authorised Prescriber pathway; for how regulated cannabis access actually works here.

The federal baseline: Schedule I and what it means

Under the US Controlled Substances Act (CSA), cannabis, classified there as "marihuana" in the original legislative text, sits in Schedule I alongside heroin and lysergic acid diethylamide. Schedule I under the CSA means the federal government's position is that the substance has no currently accepted medical use and a high potential for abuse. That classification has not changed since 1970, despite decades of petitions and rescheduling proceedings.

In May 2024, the US Drug Enforcement Administration (DEA) proposed rescheduling cannabis from Schedule I to Schedule III, following a recommendation from the Department of Health and Human Services. At the time of writing, that process is ongoing and has not been finalised. If it proceeds, Schedule III would still mean federal regulation, but the research and commercial barriers would be significantly lower than they are now.

The federal prohibition creates real friction. Cannabis businesses operating legally under state law cannot access standard US federal banking services without risk. Interstate transport of cannabis remains federally illegal regardless of whether both states have legalised it. And research has historically been constrained by the need to use federally approved supply; though that has begun to ease.

State-level legalisation: a genuinely fragmented map

Since California first authorised medical cannabis use in 1996 under Proposition 215, state-level reform has spread unevenly across the country. By mid-2025, 24 states plus the District of Columbia have legalised cannabis for adult recreational use. Around 38 states have medical cannabis programmes of varying scope.

Each state programme operates independently. Some states require physician certification; others use a broader "practitioner" category. Possession limits, allowable product forms, licensing structures for cultivators and dispensaries, and testing requirements all vary by jurisdiction. There is no federal equivalent of Australia's ARTG, no single ARTG-style national product register that a cannabis product must clear before sale. State health or agriculture departments run their own approval schemes, and quality standards differ substantially.

Tetrahydrocannabinol (THC) potency limits, labelling obligations, and required testing panels for pesticides and heavy metals are set state by state. A product that clears testing in one state may not meet the requirements of a neighbouring one, and, again, you cannot legally move it across that border anyway.

The 2018 Farm Bill and the hemp distinction

The Agricultural Improvement Act of 2018; known universally as the Farm Bill, carved hemp out of the federal definition of cannabis. Hemp is defined under that legislation as Cannabis sativa L. with a delta-9 THC concentration of no more than 0.3% on a dry weight basis. This was a genuinely significant shift. It made hemp-derived cannabidiol (CBD) federally legal to cultivate and sell as an agricultural commodity, though the Food and Drug Administration (FDA) separately regulates CBD in food and dietary supplements, and that regulatory picture remains unresolved.

The Farm Bill also inadvertently opened the door to a grey market in hemp-derived cannabinoids. Because the 0.3% cap applies specifically to delta-9 THC, producers began converting CBD into delta-8-THC, delta-10-THC, HHC, and other semi-synthetic variants that were not explicitly named in the legislation. Some states have moved to close that gap; others haven't. The 2023 Farm Bill reauthorisation process saw significant debate about tightening the definition, though the bill had not passed at the time this article was written.

I'll be honest: I find the delta-8 grey market genuinely difficult to follow from Canberra, and I reckon most US regulators find it difficult too. It's a case study in how a single definitional gap in primary legislation can generate an entire product category almost overnight.

Medical cannabis programmes: what they typically cover

US state medical programmes generally require a patient to obtain certification from a licensed physician or, in some states, a nurse practitioner or other provider who determines the patient has a "qualifying condition." Those conditions vary by state, some lists are narrow, others broad enough to include general "chronic pain" or physician discretion.

Patients receive a registry identification card and can then purchase from licensed dispensaries. Products range from dried flower and oils through to standardised extracts, edibles, and topicals. The cannabinoid profiles of these products; including the balance of THC and CBD, the presence of minor cannabinoids like CBG or CBN, and the terpene content, vary considerably. Some dispensaries stock both full-spectrum and broad-spectrum formulations, and the terminology, whilst increasingly standardised, is not federally regulated.

Unlike Australia's framework, there is no single federal equivalent to the TGA's Schedule 8 controlled drug classification for medicinal cannabis products. In states where adult-use is legal, the distinction between medical and recreational supply is largely administrative and financial, medical patients often pay less tax and may access higher potency products.

Research constraints and the Schedule I problem

One downstream consequence of the federal Schedule I classification has been a constrained research environment. Researchers at US universities receiving federal funding have historically faced significant obstacles in conducting human studies with cannabis, including being limited to supply from a single federally authorised grower until 2021, when the DEA expanded its list of approved research cultivators.

This matters for understanding the endocannabinoid system more broadly. The US National Institutes of Health (NIH) funds substantial basic science; work on CB1 receptor and CB2 receptor pharmacology, on endogenous ligands like anandamide, and on the behavioural and physiological roles of the system, but clinical research with whole-plant cannabis has been harder to execute rigorously than in jurisdictions with clearer frameworks. The proposed DEA rescheduling to Schedule III would, if finalised, substantially ease those barriers.

What Australian readers should take from this

The US framework is not a model Australia has followed, and the differences are more than cosmetic. Australia's approach, TGA scheduling, the Special Access Scheme, the Authorised Prescriber pathway, and GMP manufacturing requirements under the Good Manufacturing Practice framework; is a nationally consistent, prescriber-centred system. The US approach is, by contrast, a mosaic of state experiments running in tension with unchanged federal law.

Neither system is without problems. Australia's pathway has been criticised for access friction, particularly in regional areas. The US system has produced broad access in some states but with wildly inconsistent product quality and very limited standardisation. My view, for what it's worth, is that the absence of a federal product register in the US is the single biggest structural gap, and one that the proposed rescheduling alone would not fix.

If you're an Australian reading this because you're curious about your own access options, the TGA's published information on the Special Access Scheme and Authorised Prescriber pathways is the right place to start, not a comparison with California law.

Sources

• Drug Scheduling, US Drug Enforcement Administration (DEA)
• Cannabis Policy in the United States: Historical Overview and Current Landscape; NCBI / PubMed Central
• FDA and Cannabis: Research and Drug Approval Process, US Food and Drug Administration
• Good Manufacturing Practice, Therapeutic Goods Administration (TGA)

, Marcus Hale, Regulatory researcher; TGA & access law