California legalized cannabis in two steps, twenty years apart. In 1996, voters passed Proposition 215, making California the first state to legalize medical cannabis. In 2016, they passed Proposition 64, legalizing it for adults 21 and older, and the first licensed adult-use sales began on January 1, 2018.
In between came a raid on a San Francisco buyers' club, a Supreme Court defeat, a failed legalization vote and nearly two decades of patients and dispensaries operating without clear state rules. This is how it happened, in order. The sources are linked at the end.
Before 1996: San Francisco and the AIDS crisis
Much of the early push for medical cannabis in California came from San Francisco during the AIDS crisis. Its best-known figure was Dennis Peron, an activist who watched an earlier partner, Jonathan West, die of AIDS. Cannabis had eased the nausea and pain West felt from his medications.
In 1991, Peron helped write Proposition P, a San Francisco measure asking the city to recommend that California add cannabis to its list of approved medicines. City voters passed it overwhelmingly. Peron also opened the San Francisco Cannabis Buyers' Club, which supplied cannabis to people with AIDS, cancer and other serious illnesses. State agents raided and closed it in August 1996, three months before the statewide vote.
1996: Proposition 215
On November 5, 1996, California voters passed Proposition 215, the Compassionate Use Act, by 55.6 percent to 44.4 percent, with more than 5.3 million votes in favor. Peron helped write it.
The measure was short. It protected patients and their caregivers from state prosecution for possessing or growing cannabis for medical use when a physician recommended it, and it protected doctors from being punished for making those recommendations. It didn't create a legal way to buy cannabis, or any rules for the businesses that would supply it. That gap shaped the next twenty years.
2003: SB 420 and the patient ID card
In 2003, the Legislature passed SB 420, which set up the state's Medical Marijuana Program. It created the voluntary state Medical Marijuana Identification Card, issued through counties, so patients had a way to show police they were protected. It also set default possession limits and recognized patient collectives.
The card program still exists. For what it does today, and whether it's worth getting, see do you need a medical card in California.
2005: The federal pushback
Cannabis stayed illegal under federal law. In 2005, a case brought by two California patients, Angel Raich and Diane Monson, reached the U.S. Supreme Court. In Gonzales v. Raich, the Court ruled 6 to 3 that Congress's power over interstate commerce let federal law reach even cannabis grown locally for personal medical use under state law.
The ruling didn't overturn Proposition 215. It meant that patients protected under state law could still be prosecuted under federal law. Federal law itself didn't change for patients until April 2026, when the federal government moved state-licensed medical marijuana to a less restricted category. See cannabis and federal law.
2010: Proposition 19 fails
In 2010, Proposition 19 asked voters to legalize cannabis for adults 21 and older and to let state and local governments regulate and tax its sale. It failed, 46.5 percent to 53.5 percent. California would not vote on adult-use legalization again for six years, and by then Colorado and Washington had gone first, in 2012. See how countries legalized cannabis, year by year.
2015: The first state rules for medical cannabis
"Since the passage of Proposition 215 in 1996 the industry has operated largely in a shadowy grey area," said Assemblymember Jim Wood, who wrote one of the three bills that changed that. In October 2015, Governor Jerry Brown signed three bills, AB 243, AB 266 and SB 643, known together as the Medical Marijuana Regulation and Safety Act. They created California's first statewide licensing and regulation system for the medical cannabis industry.
2016: Proposition 64
On November 8, 2016, voters passed Proposition 64, the Adult Use of Marijuana Act, by 57.1 percent to 42.9 percent, with almost 8 million votes in favor.
Proposition 64 made it legal under state law for adults 21 and older to possess up to 28.5 grams of cannabis and 8 grams of concentrate, and to grow up to six plants at home. It created state taxes and a licensing system for adult-use businesses, and it let cities and counties regulate or ban cannabis businesses locally.
It also looked backward. Proposition 64 let people with past cannabis convictions ask a court to have them reduced or dismissed if the conduct would be legal or a lesser offense under the new law. In 2018, AB 1793 required the state to identify those eligible records itself, instead of leaving it to each person to apply.
For today's purchase and possession limits, see how much weed you can buy in California.
2017 to 2018: One system, and the first legal sales
California then had two separate frameworks, one for medical cannabis and one for adult use. In 2017, SB 94 merged them into one, the Medicinal and Adult-Use Cannabis Regulation and Safety Act, which still governs the industry.
On January 1, 2018, licensed retailers began selling cannabis to adults 21 and older. It was the first day of legal adult-use sales in California.
2021 to now: one regulator, and local control
In 2021, California combined its three cannabis licensing programs, previously split between the Bureau of Cannabis Control, the Department of Food and Agriculture and the Department of Public Health, into one agency, the Department of Cannabis Control.
Local control, written into Proposition 64, still decides where cannabis can be sold. According to the Department of Cannabis Control, 53 percent of California's cities and counties don't allow any type of cannabis business, 284 of 540. That's why licensed stores are clustered in some areas and absent from others. To check whether a store is licensed, see how to tell if a California dispensary is licensed.
California's cannabis timeline at a glance
- 1991: San Francisco voters pass Proposition P.
- August 1996: State agents close the San Francisco Cannabis Buyers' Club.
- November 1996: Proposition 215 passes with 55.6 percent. California becomes the first state to legalize medical cannabis.
- 2003: SB 420 creates the state medical ID card program.
- 2005: The Supreme Court rules in Gonzales v. Raich that federal law still applies to California patients.
- 2010: Proposition 19 fails with 46.5 percent.
- 2015: The Medical Marijuana Regulation and Safety Act creates state licensing for medical cannabis.
- November 2016: Proposition 64 passes with 57.1 percent.
- 2017: SB 94 merges the medical and adult-use systems.
- January 1, 2018: Licensed adult-use sales begin.
- 2021: The Department of Cannabis Control becomes the single state regulator.
Our California stores are part of the market those votes built. Find a Dr. Greenthumb's location.
Sources and further reading
- Proposition 215: Medical Use of Marijuana — UC Law San Francisco, California Ballot Propositions database, with the November 1996 vote totals
- Proposition 215 analysis — California Legislative Analyst's Office
- November 2, 2010: Proposition 19 — UC Berkeley Institute of Governmental Studies, with the vote totals
- November 8, 2016: Proposition 64 — UC Berkeley Institute of Governmental Studies, with the vote totals
- Gonzales v. Raich, 545 U.S. 1 (2005) — U.S. Supreme Court opinion
- Medical Marijuana Regulation and Safety Act signed — Office of Assemblymember Jim Wood, October 8, 2015 (archived copy)
- Dennis Peron, early medical marijuana advocate, dies at 71 — The Boston Globe, 2018
