A Guide to Colorado Marijuana Laws

marijuana plants

When can I legally use and purchase marijuana in Colorado?

Recreational marijuana use is legal in Colorado under Article 18, Section 16 of the Colorado Constitution.

However, possession of marijuana and marijuana paraphernalia in Colorado is limited to:

  • Adults aged 21 and over, and 
  • People with a valid medical marijuana prescription for treatment of a debilitating illness.

To help you better understand Colorado's marijuana laws, our Colorado criminal defense lawyers discuss the following, below:

close up of man's mouth with a lighted joint in it

1. Who may legally purchase marijuana in Colorado?

Adults aged 21 and older may legally buy or possess up to one ounce of marijuana for their personal use.  All forms of marijuana are legal – including buds (flowers), concentrates and edibles. You are not limited to one form of marijuana at a time, but can mix and match.

Marijuana stores may legally operate in Colorado between the hours of 8am and midnight. However, local ordinances may contain tighter restrictions. Denver, for instance, requires stores to close by 7 PM.

In Colorado, marijuana must not be consumed in plain view of, or in a place open to, the general public. Doing so can – and often will -- result in your receiving a ticket and a fine.

However, you may freely consume marijuana in private so long as it does not endanger another person.

2. Changes to Colorado's marijuana purchasing law effective October 1, 2016

The Colorado Marijuana Enforcement Division has decided that since concentrated cannabis and edibles have more THC than other forms of marijuana, there should be further restrictions on how much you can purchase at one time.

Therefore, as of October 1, 2016, 1 ounce of marijuana flowers = 8 grams of concentrate = 800 mg of edibles. A reputable retail marijuana sales outlet can help you work out the legally acceptable limits should you wish to combine forms during a single purchase.

Concentrated cannabis is sometimes variously known as marijuana concentrate, hash, resin, wax or shatter, among other names.

3. Can I share my marijuana?

People who may legally possess marijuana may also give (but not sell) up to one ounce of weed to another person who is at least 21 years of age.

4. Can I grow marijuana in Colorado?

People who are legally entitled to use or possess marijuana may also grow, transport, possess or process up to six marijuana plants, as long as no more than three of the plants are mature.

The plants must be grown in an enclosed, locked space, not openly or publicly, and must not be made available for sale. The marijuana must also be processed on the premises where the plants were grown.

5. Colorado driving and marijuana

It is a crime to drive in Colorado if:

You are considered under the influence (DUI) in Colorado when:

  • You have consumed one or more drugs, or a combination of alcohol and drugs; and
  • The drugs and/or alcohol make you substantially incapable, either mentally and/or physically, to exercise clear judgment, sufficient physical control, or due care in the safe operation of a vehicle.

You are considered ability impaired (DWAI) in Colorado when:

  • You have consumed one or more drugs or a combination of alcohol and drugs; and
  • The drugs and/or alcohol affects you “to the slightest degree” – meaning you are less able than you ordinarily would have been, either mentally and/or physically, to exercise clear judgment, sufficient physical control, or due care in the safe operation of a vehicle.

Unlike alcohol, Colorado has no strict DUI “per se” legal limit for the amount of THC that can be in your blood when you drive. However, a jury may infer that you drove under the influence of marijuana if a blood test shows 5 nanograms or more of delta 9-tetrahydrocannabinol (THC) per milliliter in your blood. And if you are arrest on suspicion of DUID and you refuse to take a blood test, your refusal can be used as evidence of your guilt. It may also result in suspension of your Colorado driver's license.

A conviction for DUI can cost you over $10,000 in fines and expenses and subject you to jail time – even if you have a prescription for medical marijuana. We recommend, therefore, that you not drive after you have consumed marijuana, even if you think you are perfectly capable of driving safely.

Additionally, Colorado's “open container” law applies to marijuana as well as alcohol. This law makes it illegal to consume or to possess marijuana in an open container in the passenger area of a vehicle. If you are transporting marijuana in a car or other motor vehicle, we recommend you keep it in the trunk or glove compartment, or a sealed retail bag or locked container.

prescription bottle with marijuana buds pouring out of it

6. Who may legally use medical marijuana in Colorado?

Medical marijuana use is governed in Colorado by Article 18, section 14 of the Colorado constitution and by Title 12, Article 43.3. of the Colorado Revised Statutes, known as the “Colorado Medical Marijuana Code.”

You may legally use medical marijuana solely to treat a “debilitating medical condition,” defined as:

  • Cancer, 
  • Glaucoma,
  • Human Immunodeficiency Virus (HIV),
  • Acquired Immune Deficiency Syndrome (AIDS), or
  • A chronic or debilitating disease or medical condition, which causes you to suffer:
    • cachexia (wasting syndrome / severe weight loss); 
    • severe pain; 
    • severe nausea; 
    • seizures (including those characteristic of epilepsy); 
    • persistent muscle spasms (including those characteristic of multiple sclerosis); or
  • Any other medical condition approved by the state health agency, including in response to a patient or physician's petition.

7. Who may purchase medical marijuana?

Marijuana may be legally purchased by medical marijuana patients and their primary care-givers. You are a “primary care-giver” if you are at least 18 and you have significant responsibility for managing the well-being of someone with a debilitating medical condition.

Medical marijuana users and their primary caregivers may collectively possess no more marijuana than is medically necessary to address a debilitating medical condition. However, the following limits are automatically deemed lawful:

  • Up to two ounces of a usable form of marijuana; and
  • Up to six marijuana plants, with three or fewer being mature, flowering plants that are producing a usable form of marijuana.

Medical necessity of amounts greater than these is an affirmative defense to criminal charges. This means that the burden will be on you to prove that such amount was necessary.

8. Special requirements for medical marijuana users under 18 years of age

If a patient is less than 18 years old, he or she may not use medical marijuana unless all of the following conditions have been met:

  1. Two physicians have diagnosed the patient as having a debilitating medical condition;
  2. One of these physicians has explained the possible risks and benefits of medical use of marijuana to the patient and each of the patient's parents residing in Colorado;
  3. The physicians have provided the patient with certain legally required written documentation;
  4. Each of the patient's parents residing in Colorado consents in writing to the state health agency to permit the patient to engage in the medical use of marijuana;
  5. A parent residing in Colorado consents in writing to serve as a patient's primary care-giver;
  6. A parent serving as a primary care-giver completes and submits an application for a medical marijuana registry identification card;
  7. The state health agency approves the patient's application and transmits the patient's registry identification card to the parent designated as a primary care-giver;
  8. The patient and primary care-giver collectively possess no more marijuana than the patient is entitled to possess; and
  9. The primary care-giver controls the acquisition of such marijuana and the dosage and frequency of its use by the patient.

9. Use of marijuana in National Parks and other federal properties

Rocky Mountain National Park

Marijuana use and possession are still crimes under 21 U.S. Code 811, the United States Controlled Substances Act (CSA)

The CSA governs the use of marijuana on federally owned property, including (without limitation):

  • National parks, forests or monuments,
  • Post offices,
  • Courthouses,
  • Airports,
  • Federal housing, 
  • Veterans Administration buildings, and
  • Private facilities (such as ski runs) located on federal land.

Penalties for a first offense for possession of marijuana on federal land can include:

  • Up to 1 year in jail, and 
  • A fine of up to $1,000 on the first offense.

Second and subsequent offenses carry mandatory incarceration and longer maximum sentences and fines.

10. Illegal use of marijuana in Colorado

Colorado's criminal marijuana laws are set forth primarily in 18-18-406, C.R.S., offenses relating to marijuana and marijuana concentrate. They fall into two basic categories:

10.1. Possession of more marijuana than is legally permissible

Possessing, transferring or transporting more than the legally permissible amount of marijuana can be charged as a non-criminal petty offense, a misdemeanor, or a felony, depending on:

  • Whether you possessed the marijuana for personal use or with intent to sell it, and
  • The amount and type of marijuana you possessed.

First-time possession of not more than 2 ounces of marijuana for personal use is a non-criminal petty offense. It can be punished by a fine of up to $100.

At the high end, possessing more than 12 ounces of marijuana buds or more than 3 ounces of marijuana concentrate is a class 4 drug felony. Consequences of a Colorado class 4 drug felony can include:

  • Up to 1 year in jail, and 
  • A fine of up to $100,000.

10.2. Sale of marijuana in Colorado

Selling marijuana is always a crime in Colorado unless you are an authorized seller acting in compliance with Colorado marijuana laws.

Punishment for selling marijuana in Colorado depends on:

  • The amount of marijuana involved, and
  • The age of the person you sold it to.

At the high end, the sale of marijuana is a Colorado class 1 drug felony if the amount involves:

  • More than 2 ½ pounds of marijuana, or 
  • More than 1 pound of marijuana concentrate or you sell concentrate to a minor who is at least 2 years younger than you.

Colorado class 1 drug felonies can be punished by as much as 32 year in prison.

For more information on Colorado marijuana crimes, penalties and defenses, we invite you to browse our articles on specific marijuana crimes.

Call us for help…

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Colorado has some of the most lenient marijuana laws in the country. Yet the Colorado marijuana laws are complex and still developing.

If you or someone you know has been charged with a criminal violation of Colorado's laws on marijuana use, possession or sale, we invite you to contact us for a free consultation.

Our compassionate Colorado drug lawyers have a great deal of experience defending clients accused of violating marijuana and other Colorado drug laws.

To discuss your case confidentially, fill out the form on this page or call us at our Denver home office:

Colorado Legal Defense Group
1400 16th Street
16 Market Square
Denver CO 80202
(720) 955-6112

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