Adults 21 and older can legally possess up to 3 ounces of marijuana in Missouri, so the penalties for possession now depend on your age, how much you have, and where you have it. Possession over the limit can bring fines or a criminal charge, and a criminal charge can still leave a drug conviction on your record.
How Did Amendment 3 Change Marijuana Penalties in Missouri?
Amendment 3 made it legal for adults 21 and older to possess up to 3 ounces of marijuana in Missouri, and it took effect on December 8, 2022. Before then, even a small amount could mean a fine and a drug conviction, and misdemeanor defense was often the way to protect a criminal record.
Amendment 3 also changed three other things. Public use is still not allowed. Possession by someone under 21 is generally handled as a civil penalty instead of a crime, though local rules differ. And according to Missouri court reports, many past marijuana offenses were supposed to be expunged automatically.
Possession of Marijuana Is Not Fully Legal in Missouri
Marijuana is not fully legal in Missouri, because the Missouri Constitution sets limits on age, amount, and place. Missouri law regarding marijuana possession considers marijuana a controlled substance, which is still illegal to possess, use, grow, or sell in Missouri outside the exceptions Amendment 3 created for adults 21 and older.
Before Amendment 3, the penalty for first-time possession of 10 grams or less of marijuana was just a fine of $500 and no possibility of jail time. That history matters because a marijuana charge can still affect your criminal record if it was filed before the change or involves more than the legal amount.
Therefore, if you plead guilty to unlawful use of drug paraphernalia or a possession of marijuana charge that is still a crime, you will end up with a drug conviction on your criminal record. Having a drug conviction on your record will make it very difficult to find a job, rent an apartment, or get federal financial aid for college.
What Happens If You Have More Than 3 Ounces?
Having more than 3 ounces can lead to fines or a criminal charge, depending on how much you have. The exact penalty depends on the amount, any prior offenses, and the court where the case is prosecuted.
Read any ticket or summons closely, and do not assume it will be treated as a minor fine. Andrea reviews marijuana tickets and misdemeanor charges to see what the prosecutor can actually prove.
What Happens If You Are Under 21 With Marijuana?
If you are under 21, possession of marijuana is not legal, and a police officer can still give you a ticket. Under Amendment 3, possession of 3 ounces or less by a person under 21 is generally a civil penalty rather than a criminal charge. Local ordinances differ, so the ticket may name a city ordinance instead of state law.
Charges for people under 21 can also be filed as a minor in possession case when alcohol is involved. If you are under 21 and have a ticket, bring it to a free consultation so Andrea can read exactly what you were charged with.
How To Avoid Getting Caught With Marijuana
The best way to avoid getting caught with weed is to restrict yourself to smoking it in your own home, because public use is not allowed. If you smoke pot at home and decide to go out later, you should take a shower and change your clothes before leaving your house, and don’t bring any weed or paraphernalia with you. If you do bring weed or paraphernalia with you in your car, don’t leave it out in the open where a police officer could easily see it.
Of course, if you feel impaired in any way, do not drive, or else you risk getting charged with DUID (Driving Under the Influence of Drugs). Missouri law does not permit using marijuana in a moving vehicle.
Even if you are not impaired, if a police officer pulls you over for a traffic violation and finds a baggy of weed or a one-hitter in your car, the officer may arrest you but will more likely just give you a ticket for possession of marijuana and/or drug paraphernalia and let you go. Whether an officer can search your car because of the smell of marijuana is a question to ask an attorney, because Amendment 3 changed what is legal to carry.
For more helpful tips for avoiding a drug conviction, see my previous blog post “Best & Worst Places to Smoke Weed in Missouri.”
Were Past Marijuana Charges Expunged Automatically?
Many past marijuana convictions were supposed to be expunged automatically after Amendment 3. According to Missouri news reports, courts had until June 8, 2023 for misdemeanors and December 8, 2023 for most felonies, and violent offenses and impaired driving offenses were excluded. Some records were not cleared on time, and the Missouri Independent reported on this in June 2026.
To check your own record, search your name on Case.net, the Missouri Courts online case search. If an old marijuana case still shows up, contact the circuit clerk of the court that handled it.
An Attorney Can Keep Marijuana Charges Off Your Criminal Record
You will need to hire an experienced criminal defense attorney to represent you if you want to keep a marijuana charge off your criminal record. Andrea handles misdemeanor cases and traffic and misdemeanor charges in municipal court and St. Louis area courts.
It is very common for my clients to never have to appear in court. However, the outcome of your case depends on many factors, such as:
- How old are you?
- Do you have any prior drug-related arrests, charges, or convictions?
- Which court is your case being prosecuted in?
- How much marijuana were you caught with?
- Were you cooperative and polite to the police officer?
Most attorneys offer a free consultation and can give you a flat-fee price quote for how much they will charge to represent you, including an estimate of the fines and court costs you will have to pay to the court to get your charges reduced.
Frequently Asked Questions
How Much Marijuana Is Legal to Possess in Missouri?
Adults 21 and older can legally possess up to 3 ounces of marijuana in Missouri. Possession over that amount can bring fines or a criminal charge.
Can You Smoke Marijuana in Public in Missouri?
No, public use of marijuana is not allowed in Missouri, even for adults 21 and older. Use is generally limited to private property, and it is not permitted in a moving vehicle.
Does Missouri Have Automatic Expungement for Marijuana?
Yes, Amendment 3 required courts to expunge many marijuana offenses automatically, with 2023 deadlines for misdemeanors and most felonies. Some cases were missed, so search your name on Case.net and contact the circuit clerk if an old case still appears.
Can You Get a Marijuana Ticket in Missouri if You Are Under 21?
Yes, you can get a marijuana ticket in Missouri if you are under 21, because possession by anyone under 21 is not legal. Possession of 3 ounces or less is generally a civil penalty, and the details depend on the local ordinance on your ticket.
The Bottom Line
Marijuana possession in Missouri is legal for adults 21 and older up to 3 ounces, but being over the limit, under 21, or in public can still lead to a ticket or charge. Andrea handles every call and every case personally. She offers a free consultation with a flat fee price quote up front. Contact St. Louis marijuana lawyer Andrea Storey Rogers at The Rogers Law Firm at (314) 724-5059 or arogers@rogerslawfirmllc.com for a free consultation about your Missouri marijuana or drug paraphernalia charges.
You can also review pricing before you call.
