Are Drugs Decriminalized in Colorado? Cannabis, Prop 122, Penalties

Drugs are not broadly decriminalized in Colorado. Cannabis is fully legal for adults 21 and older, and five specific psychedelic substances were decriminalized for personal use by voters in 2022. Everything else on the state’s controlled substances schedules, including cocaine, heroin, methamphetamine, and prescription opioids taken without authorization, remains a criminal offense to possess. That said, Colorado’s sentencing framework increasingly steers people caught with small amounts toward probation and treatment rather than prison.

Cannabis Is Legal, Not Just Decriminalized

Colorado voters approved Amendment 64 in 2012, and the state now runs a licensed dispensary system for adult recreational use.¹ If you are 21 or older, you can buy, possess, and use cannabis within the limits set by state law.

How Colorado treats marijuana possession depends on how much you have:

Two ounces or less: legal for adults 21+. Gifting up to two ounces to another adult without payment is also legal.
More than two ounces but not more than six ounces: a level 2 drug misdemeanor.
More than six ounces: a level 1 drug misdemeanor.²

Medical marijuana patients may possess up to two ounces of usable marijuana under the Colorado Constitution, with the possibility of a higher amount when a physician certifies medical necessity.

You can grow your own. Colorado allows up to six plants per person, no more than three flowering at once, capped at twelve total per residence regardless of how many adults live there.² If minors live in the home, the growing area must be independently enclosed and locked.

Public Use and Driving

Consuming cannabis where the public can see you is illegal statewide. Openly consuming two ounces or less in public is a drug petty offense, punishable by a fine of up to $100 and up to 24 hours of community service.²

Driving is where legal use turns into a serious criminal charge. Colorado law creates a legal inference that a driver is impaired when a blood test shows five nanograms or more of active THC per milliliter of whole blood.³ Unlike alcohol’s 0.08 BAC cutoff, that number is a “permissible inference” rather than automatic proof. Prosecutors can still pursue charges below five nanograms if other evidence shows impairment, and drivers above the threshold can technically argue they were not impaired. In practice, testing above five nanograms makes a DUI charge very difficult to fight.

Five Psychedelics Decriminalized Under Proposition 122

In 2022, voters approved Proposition 122, the Natural Medicine Health Act. The law covers five specific compounds: psilocybin, psilocin, dimethyltryptamine (DMT), ibogaine, and mescaline. Peyote cactus is explicitly excluded.⁴

For adults 21 and older, possessing, using, growing, transporting, and sharing these substances without payment are all lawful under state law. The critical phrase is “without remuneration.” Selling remains a crime. You can grow psilocybin mushrooms at home and give them to a friend, but you cannot charge for them outside the regulated system.⁴

Proposition 122 also created licensed “healing centers” where adults can use psilocybin under professional supervision. The state began issuing licenses in January 2025. Those centers currently offer only psilocybin and psilocin services; after June 1, 2026, the Natural Medicine Advisory Board may recommend expanding services to DMT, ibogaine, and mescaline.⁴

Every Other Controlled Substance Is Still Illegal to Possess

Outside cannabis and the five decriminalized psychedelics, possession of a controlled substance is a criminal offense under C.R.S. 18-18-403.5. The penalty depends on the substance and the weight.

Schedule I and II Substances

Possessing up to four grams of a Schedule I or II controlled substance, which covers cocaine, heroin, methamphetamine, MDMA, and prescription opioids taken without authorization, is a level 1 drug misdemeanor. Sentencing runs from six months to 18 months in jail, with fines between $500 and $5,000.⁵ First-time offenders with small amounts are frequently sentenced to probation with mandatory substance abuse treatment rather than jail.

More than four grams jumps to a level 4 drug felony. The presumptive range is six months to one year in prison with fines from $1,000 to $100,000, and aggravating circumstances can push it to one to two years.⁶

Some substances trigger felony treatment regardless of the four-gram line. Any amount of flunitrazepam, ketamine, GHB, or cathinones is charged as a level 4 drug felony.⁵

Schedule III, IV, and V Substances

Possessing any quantity of a Schedule III, IV, or V substance (other than the ketamine, GHB, and cathinones carve-outs) is a level 1 drug misdemeanor with the same six-to-eighteen-month range.⁵ A fourth or subsequent conviction escalates to a level 4 drug felony.

Fentanyl Is Treated More Harshly

Colorado singles out fentanyl, carfentanil, and related synthetic opioids. Legislation passed in 2022 lowered the felony possession threshold for fentanyl-containing substances to one gram, compared with four grams for other Schedule I and II drugs. Selling a dose of fentanyl that results in someone’s death can be charged as a level 1 drug felony, carrying a potential sentence of eight to 32 years in prison.⁶

For simple possession charged as a level 4 fentanyl felony, though, the framework leans toward treatment. Courts can order probation up to two years with a maximum of 180 days in county jail, or straight jail time of up to 180 days; a third or subsequent offense allows up to 364 days. The maximum fine in that posture is $1,000, well below the $100,000 cap that applies to other level 4 drug felonies.⁶

Distribution Is a Separate Question

Decriminalization and lighter possession penalties do not extend to selling or manufacturing. Distribution offenses are structured by weight and substance type, ranging from level 4 drug felonies for small quantities up to level 1 drug felonies (8–32 years) for more than 225 grams of a Schedule I or II substance, more than 112 grams of methamphetamine or heroin, or more than 50 grams of fentanyl.⁷ The gap between possession and distribution is enormous. Possessing three grams of cocaine is a misdemeanor. Selling three grams is a felony.

Paraphernalia and Overdose Immunity

Possessing drug paraphernalia is a drug petty offense with a maximum $100 fine.⁸ Paraphernalia received from an approved syringe exchange or harm reduction organization is not an offense at all. If you voluntarily tell a police officer, EMT, or first responder about a hypodermic needle before they search you or treat you, you cannot be arrested or charged for the needle or any trace residue in it.

Colorado’s Good Samaritan law gives immunity from arrest and prosecution when someone reports a drug or alcohol overdose in good faith. The protection covers both the caller and the person overdosing. You must call 911 or contact law enforcement or a medical provider, stay at the scene until help arrives, and identify yourself and cooperate.⁹

The immunity covers unlawful possession of controlled substances, marijuana possession in any amount, public marijuana consumption, drug paraphernalia, and underage alcohol or marijuana offenses, as long as the charge stems from the same event as the overdose.⁹ It does not shield you from distribution or manufacturing charges, and it does not cover offenses unrelated to the overdose.

Federal Law Has Not Changed

Every substance Colorado has legalized or decriminalized remains illegal under federal law. Cannabis is still a Schedule I controlled substance federally. Psilocybin, DMT, and the other psychedelics covered by Proposition 122 are all federally prohibited. Federal enforcement against individuals for personal possession in Colorado is rare in practice, but the conflict has real consequences: cannabis businesses cannot use standard banking services, federal employees and military personnel face termination for positive drug tests regardless of state law, and possession on federal land inside Colorado, including national parks and national forests, is a federal offense.

1
Ballotpedia. Colorado Amendment 64, Regulation of Marijuana Initiative (2012)
2
FindLaw. Colorado Revised Statutes Title 18 Criminal Code 18-18-406
3
Justia Law. Colorado Code 42-4-1301 – Driving Under the Influence
4
Colorado General Assembly. Proposition 122 Final LC Packet
5
Justia Law. Colorado Code 18-18-403.5 – Unlawful Possession of a Controlled Substance
6
Justia Law. Colorado Code 18-1.3-401.5 – Sentencing for Drug Felonies
7
Justia Law. Colorado Code 18-18-405 – Unlawful Distribution, Manufacturing, Dispensing, or Sale
8
Justia Law. Colorado Code 18-18-428 – Possession of Drug Paraphernalia
9
Justia Law. Colorado Code 18-1-711 – Immunity for Persons Who Suffer or Report an Emergency Drug or Alcohol Overdose Event