Cannabis Laws in Missouri 2026: The Amendment 3 Guide

If you live in Missouri, here’s the short version. As of 2026, cannabis is legal for adults 21 and older. You can carry up to three ounces without a card. You can grow your own with a cheap registration. And the state has erased more than 150,000 old marijuana convictions.

That last part is what makes Missouri interesting. Plenty of states legalized weed. Missouri built the cleanup right into the law.

Let me walk you through where things stand under Amendment 3. What you can do. What you still can’t. And the one provision that other states keep pointing to as a national model.

The Quick Answer

Missouri voters passed Amendment 3 on November 8, 2022, by a 53–47 margin. It changed the state constitution to legalize recreational cannabis. That language now lives in Article XIV, Section 2. The law took effect December 8, 2022. Adult-use sales began February 3, 2023.

Here’s what that means for you in 2026:

• Legal age: 21 and older.
• Possession: Up to 3 ounces of dried, processed cannabis. No medical card required.
• Purchase: Up to 3 ounces per transaction at any licensed dispensary.
• Home grow: Up to 6 flowering plants (plus 6 immature and 6 seedlings) with a registration card.
• Tax: A 6% state excise tax on retail sales, plus optional local taxes.
• Expungement: Automatic clearing of most past non-violent cannabis convictions.

If you’re new to all of this, our first-time cannabis users guide and the cannabis quantities visual guide are good companions to this one. And for the bigger picture, see our cannabis legalization in the United States 2026 overview and the state-by-state cannabis laws 2026 breakdown.

Possession & Purchase: What You Can Carry

Under Article XIV, any adult 21 or older can possess up to three ounces of dried, processed cannabis. (Other product forms count by their equivalent.) You don’t need to register. You don’t need a medical card. Walk into a licensed dispensary with a valid ID. You can buy up to three ounces in a single transaction.

Missouri dispensaries carry the full range. Flower, pre-rolls, concentrates, edibles, topicals, and beverages. Not sure which to pick? Our guide on how to choose between flower, edibles, and concentrates breaks down what each one does and how fast.

A few important boundaries:

• Carrying between the legal limit and twice the limit (3 to 6 ounces) is not a crime. But it can trigger civil penalties.
• The 3-ounce consumer limit is separate from the medical patient limits. Registered patients may hold a 60-day supply (12 ounces). Growers can hold a 90-day supply, with the excess kept in a locked facility.
• You can’t combine your consumer limit and a patient limit to carry more.

One thing people get wrong: THC percentage on the label is a poor guide to how a product will hit you. We dug into why in THC percentage is a terrible way to choose cannabis and why your dispensary labels are mostly wrong. Worth a read before your first trip. So is how to choose the right dispensary.

Home Grow: Yes, With a Registration

This is one of Missouri’s more generous rules. Adults 21 and over can grow cannabis at home. But you need a consumer personal cultivation registration card from the Division of Cannabis Regulation (DCR). It costs $100 a year.

Once registered, you can grow:

• 6 flowering plants
• 6 non-flowering plants 14 inches tall or more
• 6 seedlings under 14 inches

Two registered adults can grow at the same home. That doubles the numbers to 12 / 12 / 12. But that’s the ceiling per address, no matter how many adults live there.

The rules that matter:

• All growing must happen at a private residence in an enclosed, locked space that the public can’t see.
• Any harvested cannabis above your 3-ounce limit must stay locked at that home.
• You can’t grow at a place of business.
• Your card doesn’t override a landlord’s lease or local ordinances.

Thinking about it? Start with our how to grow cannabis at home beginner’s guide. Then read the cannabis growing stages seed to harvest timeline. Weighing your setup? Indoor vs outdoor cannabis growing and the grow tent setup guide will save you money. Renters, read can your landlord ban cannabis first.

Automatic Expungement: The Model Other States Study

Here’s the part that earned Missouri national attention. When Missourians passed Amendment 3, they did something no other state’s voters had done. They approved statewide automatic expungement of non-violent cannabis offenses at the ballot box.

Most states that “expunge” cannabis records make you do the work. You petition the court. You hire a lawyer. You file paperwork. You wait. Amendment 3 flipped that. It put the burden on the state. The constitution ordered circuit courts to review and clear eligible records on a fixed schedule:

• Misdemeanors: cleared by June 8, 2023. That’s six months after the law took effect.
• Most felonies: cleared by December 8, 2023, for people no longer under state supervision.
• People still in prison or on probation could petition to vacate their sentences.

Funding came baked in. A slice of the 6% cannabis sales tax pays for the court work.

The results have been real. By the end of 2023, Missouri courts had cleared more than 100,000 cannabis cases [NORML, 2023]. By mid-2025 that figure passed 150,000 [Greenway, 2025]. And advocates say hundreds of thousands more remain. Many are buried in old paper records that date back roughly a century.

Dan Viets is the Missouri NORML coordinator who helped write Article XIV. He called automatic expungement “one of the most significant parts” of the law. It clears old damage. It also heads off roughly 20,000 cannabis arrests a year going forward [Jaeger, 2022].

It hasn’t been smooth. Some rural counties missed deadlines. Clerks have described spending up to 90 minutes per hand-pulled paper file. But the design is what matters. Automatic. State-funded. Constitutionally required. That’s why reform advocates in other states keep citing Missouri as the template to copy.

Want the backstory on why these records mattered? Our pieces on the war on drugs and the Reagan era and the 1970 Controlled Substances Act trace how we got here.

Microbusiness Licenses: Built for Equity

Amendment 3 also created a license type you won’t find in most states. It’s called the marijuana microbusiness facility. The goal is to open ownership to people who’d normally be shut out of a capital-heavy industry.

A microbusiness comes in two forms. A dispensary facility handles retail. A wholesale facility handles small-scale growing and manufacturing. What sets them apart is who can own them. The constitution requires majority ownership by people who meet at least one equity criterion. For example:

• A net worth under $250,000 and income below a set threshold,
• Living in a ZIP code hit hard by past cannabis enforcement or high poverty,
• Being a veteran with a service-connected disability, or
• Having a past non-violent cannabis offense (or a close family member who does).

Licenses go out by lottery, not a scored contest. They’re spread evenly across Missouri’s congressional districts. The DCR issued its first 48 microbusiness licenses in October 2023 [DHSS, 2023]. That was 32 wholesale and 16 dispensary, with more rounds since.

The program hasn’t been drama-free. Regulators have warned applicants more than once about gaming the eligibility rules. But the intent is clear. Tie legalization to repair, not just revenue.

Public Use, Driving & Taxes

A few rules people violate without realizing it:

Public consumption is illegal. You can’t smoke cannabis in public. Do it and you face a civil fine of up to $100. Use is limited to private property where the owner allows it, or to venues licensed for it. Brush up on cannabis etiquette so you don’t become that person.

Driving under the influence is banned. Amendment 3 legalized possession, not impaired driving. Cannabis DUI laws still apply. THC lingers in your body long after the high fades. So timing matters more than most people think. We covered the science in cannabis and driving: how long to wait and how long THC stays in your system.

Selling to anyone under 21 is illegal. Adult-use means adult.

Taxes. The state charges a 6% excise tax on adult-use sales. Local governments may add their own tax, often up to 3%. So your total at checkout varies by city and county. Medical patients pay a lower rate. The money funds the DCR first. Then it covers expungement costs, veterans’ services, the public defender system, and local governments.

Crossing state lines is still illegal. Cannabis remains federally controlled. So you can’t legally carry Missouri-bought product into Kansas, Illinois, or anywhere else. Not even another legal state. See how to travel with cannabis and interstate cannabis commerce for why.

Frequently Asked Questions

Do I need a medical card to buy cannabis in Missouri? No. Any adult 21 or older can buy from a licensed dispensary with a valid ID. A medical card still has perks. You get higher possession limits and lower taxes. But it’s optional. If you want one, our medical marijuana card state-by-state guide explains the steps.

How much can I legally possess? Up to 3 ounces of dried, processed cannabis as a consumer. Registered medical patients can hold more.

Can I grow my own? Yes, with a $100 annual personal cultivation registration: 6 flowering plants, 6 immature, and 6 seedlings, in a locked private space.

Were old convictions really erased automatically? Yes. More than 150,000 cannabis cases have been expunged through 2025, with the state — not the defendant — initiating most of them. Older paper-record cases are still being worked through.

Can I use cannabis in public? No. Public consumption is prohibited and carries a civil fine up to $100.

Is it legal to drive after using cannabis? No. Cannabis DUI laws still apply regardless of legalization.

How to Actually Choose What Works for You

Legal access is the starting line, not the finish. The harder question is which products do what you want. And that has almost nothing to do with the indica/sativa labels on the menu. We unpack why in indica vs sativa: the myth. Then we offer a better framework in understanding High Families.

The best predictor of your experience isn’t the strain name. It’s how your body responds to a terpene and cannabinoid profile. That’s what tools like the High IQ app help you track. Log what you try. Note how it actually felt. Let your own patterns guide the next trip. As I always say, the goal isn’t to memorize a strain. It’s to know exactly why you’re high.

Key Takeaways

• Cannabis is legal in Missouri for adults 21 and older under Amendment 3 (Article XIV, Section 2).
• You can possess up to 3 ounces and buy that much per transaction. No medical card needed.
• Home grow is legal with a $100 annual registration: 6 flowering plants, 6 immature, and 6 seedlings.
• Missouri’s automatic expungement program has cleared 150,000+ cannabis cases and is studied as a national model.
• Microbusiness licenses reserve ownership for equity applicants through a lottery.
• Public use and impaired driving are still illegal, and a 6% state tax applies at the register.

Sources

• Missouri Department of Health and Senior Services, Division of Cannabis Regulation — Cannabis Regulation and Adult Use FAQs
• Missouri Constitution, Article XIV, Section 2 — Legalization, regulation, and taxation
• NORML — Missouri Legalization and 100,000 Marijuana Convictions Expunged Following Legalization
• Greenway Magazine — More than 150,000 marijuana cases expunged in Missouri
• Marijuana Moment — Missouri Voters Approve Marijuana Legalization Initiative
• The Beacon — Missourians passed Amendment 3. What’s next?
• Wikipedia — 2022 Missouri Amendment 3

This article is for educational purposes only and is not legal advice. Cannabis laws change frequently and enforcement varies by county and municipality. Always verify current rules with the Missouri Division of Cannabis Regulation or a licensed attorney before acting.