13 Medical Marijuana Statistics: States, Patients, and Qualifying Conditions

Medical marijuana programs have existed in the U.S. since California voters approved one in 1996. Thirty years later, most states have one, enrollment has grown roughly fivefold in under a decade, and in April 2026 the federal government moved state-licensed medical marijuana to Schedule III. The statistics below cover how many states and patients there are, why people enroll, how the research evidence lines up with state qualifying conditions, and what the federal change means. This page reports program and survey data only; it is not medical advice. See our medical marijuana laws page for state-by-state rules.

1. 40 states plus DC have comprehensive medical marijuana programs

As of March 1, 2026, 40 states, the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands allow comprehensive medical use of marijuana, according to the Congressional Research Service.

2. Eight more states allow only low-THC or CBD products

Eight additional states have "limited access" programs covering low-THC cannabis or CBD oil. Idaho, Kansas, and American Samoa allow neither.

3. California's 1996 law started it

California became the first state to permit medical marijuana in 1996. Our marijuana legalization statistics track how laws spread from there.

4. Registered patients grew more than 420% from 2016 to 2024

A University of Michigan analysis of state registry data, published in Annals of Internal Medicine in 2026, found the number of registered medical cannabis patients rose from about 747,000 in 2016 to about 3.9 million in 2024.

5. Enrollment often falls after adult-use legalization

The same study found that patient enrollment often declined after states legalized recreational cannabis, suggesting some people obtain cannabis outside medical programs once adult-use stores open.

6. Florida leads all states with 929,360 patients

Among states that publish counts, the largest programs tracked by the Marijuana Policy Project are Florida (929,360), Pennsylvania (441,530), and Oklahoma (310,850), followed by Texas (135,470 patients making purchases in the prior month), Illinois (119,497), Arkansas (115,073), Virginia (114,170), and Utah (114,090). Counts are current through dates ranging from mid-2025 to mid-2026.

7. National patient totals are an undercount

MPP's total of more than 3.69 million patients is a partial figure: it omits or vastly undercounts several states, including California, that do not have mandatory registries or track monthly purchasers.

8. Chronic pain made up 64.9% of reported qualifying conditions

A 2019 Health Affairs study of state registries found chronic pain was the most common qualifying condition, at 64.9% of patient-reported conditions in 2016. It remained the top reason through 2024, according to the 2026 Annals study.

9. Mental health registrations are growing fastest

Registrations for mental health conditions such as PTSD and anxiety grew substantially from 2016 to 2024, even though, as the study's authors note, evidence for those uses remains limited.

10. Only 8.3% of state qualifying conditions meet the strongest evidence standard

A 2025 study in Mayo Clinic Proceedings: Innovations, Quality & Outcomes compared the qualifying-condition lists of 38 jurisdictions with the 2017 National Academies of Sciences report. In 2024, only 8.3% of listed conditions met the standard of substantial or conclusive evidence, and among the 20 most common conditions, only chronic (long-term) pain did.

11. 88% of Americans support legal medical marijuana

In a 2024 Pew Research Center survey, 88% of U.S. adults said marijuana should be legal for medical use, recreational use, or both. 32% said it should be legal for medical use only.

12. State-licensed medical marijuana moved to Schedule III in April 2026

A final rule published in the Federal Register moved state-licensed medical marijuana to Schedule III of the Controlled Substances Act, effective April 28, 2026. The rule also covers drug products containing marijuana that are approved by the FDA; marijuana outside those two categories, including unlicensed and adult-use supply, remains in Schedule I. See our federal cannabis law page.

13. Medical licensees get federal registration and tax changes

Under the rule, state medical marijuana licensees can seek expedited DEA registration, and the federal 280E tax restriction, which barred cannabis businesses from deducting ordinary expenses, no longer applies to them.

Medical cannabis programs keep growing, but the evidence behind each qualifying condition varies widely. A few practical points:

• Talk with a clinician. Program enrollment requires a certifying provider, and a qualified professional can weigh potential benefits and risks for your situation.
• Check your state's rules. Qualifying conditions, purchase limits, and tax treatment differ by state; start with our medical marijuana laws and traveling with cannabis pages.
• Know your products. Our guides to cannabinoids and reading a COA help you compare what is in a product.
• Look at the costs. Medical purchases are taxed differently in some states; see our cannabis tax revenue statistics.

How many states have legalized medical marijuana?

As of March 2026, 40 states and DC, plus Guam, Puerto Rico, and the U.S. Virgin Islands, have comprehensive medical marijuana programs. Eight more states allow low-THC or CBD-only products, while Idaho, Kansas, and American Samoa allow neither.

How many medical marijuana patients are there in the U.S.?

About 3.9 million registered patients in 2024, up from about 747,000 in 2016, according to a 2026 Annals of Internal Medicine study. Actual numbers are likely higher because some states, including California, do not require registration.

What is the most common reason people get a medical marijuana card?

Chronic pain. It accounted for 64.9% of patient-reported qualifying conditions in 2016 and was still the most common reason in 2024. Registrations for PTSD and anxiety have grown quickly.

Is medical marijuana federally legal now?

Not fully. A federal rule effective April 28, 2026 moved state-licensed medical marijuana to Schedule III, easing registration and tax rules for licensed medical businesses. Marijuana is still a controlled substance, and state laws still apply.