Psilocybin Decriminalization
31.3M lifetime US users
The number of Americans who have used psilocybin at least once rose from 25 million in 2019 to 31.3 million in 2023, the same period during which the decriminalization wave spread from Denver and Oakland across more than a dozen US cities.
Rockhill et al., Annals of Internal Medicine, 2025
2019
year Denver became first US city to decriminalize psilocybin
March 2025
date Denver repealed city-level decrim (superseded by state law)
15+ cities
US jurisdictions with decriminalization or lowest-priority policies
Rockhill et al., Annals of Internal Medicine, 2025
View as image ↗In May 2019, Denver voters passed Initiative I-301 by a margin of 50.6% to 49.4%, making it the first US city to decriminalize psilocybin mushrooms. Within weeks, Oakland's city council followed with a unanimous vote. Within five years, more than fifteen US cities and jurisdictions had passed some form of decriminalization policy, two states had legalized psilocybin for therapeutic use, and one state had launched a therapeutic service program. A 2025 study in the Annals of Internal Medicine captured what this period produced: lifetime psilocybin use in the US rose from 25 million people (10% of adults) in 2019 to 31.3 million (12.1%) by 2023.[1]
This tracker documents each US jurisdiction that has enacted a psilocybin decriminalization or therapeutic access policy, what each policy actually does, and its current status. For the federal legal context, see psilocybin's Schedule I status: history and controversy. For the argument landscape behind these policies, see the arguments for and against psilocybin decriminalization.
Key Takeaways
- Denver, Colorado became the first US city to decriminalize psilocybin in May 2019 via ballot initiative (50.6%); the city repealed that policy in March 2025 because Colorado's statewide Prop 122 made it redundant (Siegel 2023)
- Lifetime psilocybin use in the US rose from 25 million in 2019 to 31.3 million in 2023, coinciding with the decriminalization wave; poison center calls for psilocybin also rose 201% in adults over the same period (Rockhill 2025)
- US decriminalization policies fall into three tiers: lowest-priority resolutions (advisory), enforcement-resource prohibitions (binding on police), and statewide therapeutic access programs (Oregon, Colorado, New Mexico)
- Not all "decriminalization" is equal: a lowest-priority resolution means police are advised not to prioritize arrest but technically can; an enforcement-resource prohibition legally bars spending police resources on psilocybin possession
- Michigan has the most city-level decrim coverage of any state, with policies in Ann Arbor, Detroit, and Hazel Park; Massachusetts follows with Somerville, Cambridge, and Northampton (Bhave 2025)
- Oregon and Colorado represent a different tier: not decriminalization but regulated therapeutic access, where adults can use psilocybin in licensed facilities under professional supervision
Three Policy Tiers: What "Decriminalized" Actually Means
The word "decriminalized" appears in coverage of every jurisdiction in the tracker below, but it describes fundamentally different legal situations depending on where you are. A 2023 policy analysis in JAMA Psychiatry by Siegel and colleagues mapped the landscape of US psychedelic legislative reform and identified the key distinctions.[3]
Tier 1: Lowest-priority resolutions. Some city councils have passed resolutions directing police to treat psilocybin possession as the lowest enforcement priority. These resolutions are advisory, not legally binding on individual officers. Possession remains illegal under state and federal law. Police technically could still arrest someone, but department policy discourages it. Somerville, Cambridge, and Northampton in Massachusetts used this model.
Tier 2: Enforcement-resource prohibitions. A more durable policy bars the city from spending public funds or personnel time on enforcing psilocybin possession laws. Denver's 2019 ballot initiative was this type: it legally prohibited the city from using police resources to enforce personal psilocybin possession, rather than just advising against it. Washington DC's Initiative 81, passed in 2020, was similar. These policies are more binding but still leave possession illegal under state and federal law.
Tier 3: Statewide therapeutic access. Oregon (Measure 109, 2020), Colorado (Prop 122, 2022), and New Mexico (therapeutic program, 2025) represent a different model: regulated legal access to psilocybin in licensed service centers, under professional supervision. This is not decriminalization (which tolerates possession) but a regulated permission for specific use. Adults can legally use psilocybin in these settings, which no decriminalization policy permits.
Understanding which tier applies to your jurisdiction determines what the policy actually protects and what it does not. The tracker below includes the tier for each entry.
The Tracker: US Psilocybin Decriminalization by Jurisdiction
Last updated: May 2026. All entries reflect the strongest-level policy in each jurisdiction at time of writing.
| City / Jurisdiction | State | Year | Mechanism | Tier | Status |
|---|---|---|---|---|---|
| Denver | CO | 2019 | Ballot (I-301, 50.6%) | 2 | Repealed March 2025, superseded by Prop 122 |
| Oakland | CA | 2019 | City Council (unanimous) | 2 | Active |
| Santa Cruz | CA | 2020 | City Council | 1 | Active |
| Washington, DC | DC | 2020 | Ballot (Initiative 81, 76%) | 2 | Active |
| Ann Arbor | MI | 2020 | City Council | 1 | Active |
| Detroit | MI | 2021 | Ballot | 1 | Active |
| Hazel Park | MI | 2021 | City Council | 1 | Active |
| Somerville | MA | 2021 | City Council | 1 | Active |
| Cambridge | MA | 2021 | City Council | 1 | Active |
| Northampton | MA | 2021 | City Council | 1 | Active |
| Minneapolis | MN | 2023 | Mayoral Executive Order | 1 | Active (executive orders may be reversed) |
| Tacoma | WA | 2025 | City Council | 1 | Active |
| New Mexico | NM | 2025 | State Law | 3 (therapeutic) | Active: statewide therapeutic program |
| Oregon | OR | 2020 | State Ballot (Measure 109) | 3 (therapeutic) | Active: licensed service centers operational |
| Colorado | CO | 2022 | State Ballot (Prop 122) | 3 (therapeutic) | Active: superseded Denver's city decrim |
Notes:
- Denver's 2019 Tier 2 decriminalization (Initiative I-301) was repealed by Denver City Council in March 2025 because Colorado's statewide Prop 122 created a more expansive legal framework, making the original city-level policy redundant. This was a policy success, not a reversal.
- Minneapolis's mayoral executive order is the least durable form of decriminalization. It can be rescinded by the next mayor without a vote.
- Oregon and Colorado entries are included for completeness but represent a different legal model than the decriminalization policies above them.
- Washington DC's Initiative 81 covers "entheogenic plants and fungi" broadly, including psilocybin mushrooms.
What Changed After Denver: Use Trends Across the Decriminalization Period
The five years from 2019 to 2023 saw the most rapid spread of psilocybin decriminalization policies in US history. They also saw a substantial increase in psilocybin use, documented by a 2025 multisource observational study in the Annals of Internal Medicine.[1]
Rockhill and colleagues drew on five nationally representative data sources, including the National Survey on Drug Use and Health (NSDUH), Monitoring the Future (MTF), and the National Poison Data System (NPDS). Their findings: lifetime psilocybin use rose from 25 million Americans (10% of adults) in 2019 to 31.3 million (12.1%) in 2023. Past-year use increased 44% among adults aged 18 to 29 and 188% among adults aged 30 and older.
Poison control center calls for psilocybin increased 201% among adults over the same period, 317% among adolescents, and 723% among children under 12. The children's figure is the most striking: psilocybin is not being marketed to children, and few would argue it should be accessible to them, but unsecured storage in homes where adults use psilocybin may account for accidental exposures.
Whether the decriminalization policies caused the increase in use, reflected an existing trend, or both cannot be determined from this observational data. The cities that decriminalized represent a small share of the US population; national trends were rising before any city-level policy changes took effect. What the data confirms is that the decriminalization period coincided with a significant increase in use across demographic groups.
Bhave and colleagues published what appears to be the first peer-reviewed analysis specifically of what happened after US city-level decriminalization measures passed, in the Journal of Psychoactive Drugs in 2025.[2] Their work provides the most direct evidence on decriminalization effects among the studies available at the time of writing.
Denver's 2025 Repeal: What It Means When City Decrim Is Superseded
In March 2025, Denver City Council voted to repeal Initiative I-301, the 2019 ballot measure that began the US decriminalization movement. This was not a setback for decriminalization advocates. It was a policy success story.
Denver's 2019 initiative was a Tier 2 enforcement-resource prohibition: the city was barred from spending police resources on enforcing psilocybin possession law. Colorado's Prop 122, passed by voters in 2022, went further: it created a licensed therapeutic access framework where adults can legally use psilocybin at licensed service centers. The state law made the city-level prohibition redundant, because psilocybin possession for therapeutic use was now legal under state law (within regulated parameters), which preempted local enforcement concerns entirely.
The repeal was a housekeeping measure, not a policy reversal. The state-level framework provides more protection than the original city-level policy could, which is why the city council voted to sunset the measure rather than maintain two overlapping policies.
This sequence, where city decrim is followed by statewide therapeutic access that supersedes it, may become a pattern as more states advance beyond decriminalization toward regulated access. Oregon's Measure 109 followed the same trajectory nationally: city and county decriminalization efforts that predated Measure 109 became less legally significant once the statewide framework was in place. For how Colorado's specific law differs from Oregon's approach, see how Colorado's psychedelic law differs from Oregon.
For the international comparison, including Australia's 2023 therapeutic prescribing approval, see Australia's TGA approval: the first country to prescribe psilocybin.
The Bottom Line
As of May 2026, more than fifteen US jurisdictions have enacted some form of psilocybin decriminalization or therapeutic access policy, ranging from lowest-priority city council resolutions to statewide licensed service center frameworks in Oregon, Colorado, and New Mexico. The period since Denver's 2019 ballot initiative has coincided with a significant increase in US psilocybin use across all age groups, per 2025 Annals of Internal Medicine data. Denver's 2025 repeal of its original city-level initiative represents a policy success: the city decrim was made redundant by a more expansive state law, not reversed. Decriminalization policies vary enormously in legal strength, and understanding which tier applies to a given jurisdiction determines what protection it actually provides.
Frequently Asked Questions
Sources & References
- 1RTHM-02169·Rockhill, Karilynn M et al. (2025). “The Rise of Psilocybin Use in the United States: A Multisource Observational Study..” Annals of internal medicine.Study breakdown →PubMed →↩
- 2RTHM-02058·Bhave, Ashutosh (2025). “Magic of the Mushrooms: Effects of Psilocybin Decriminalization..” Journal of psychoactive drugs.Study breakdown →PubMed →↩
- 3RTHM-01791·Siegel, Joshua S et al. (2023). “Psychedelic Drug Legislative Reform and Legalization in the US..” JAMA psychiatry.Study breakdown →PubMed →↩