Medical Cannabis Legal States Map: Reciprocity Rules
38 states and DC run medical cannabis programs. About 13 states plus DC take out-of-state cards. See which states accept them and which do not.
The short answer
There is no national number. Cannabis is still a Schedule I drug under federal law, so every possession limit comes from the state you happen to be standing in. In most adult-use states the cap lands at 1 ounce of flower, or 28 grams, for anyone 21 and older. A few states go higher: New York allows 3 ounces of flower plus 24 grams of concentrate, Missouri allows 3 ounces, Ohio 2.5 ounces, and Minnesota allows 2 ounces in public with up to 2 pounds stored at home.
Treat 1 ounce as the starting point, not the rule. The number that actually applies depends on what the product is, whether you hold a medical card, and whether the cannabis is on your person, in your car, or sitting on a shelf at home.
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Why the numbers differ so much
States wrote these rules at different times, with different regulators, and with different ideas about what a "serving" means. Three measurement styles show up again and again:
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- Flower by weight, in grams or ounces.
- Concentrate by weight, usually somewhere between 5 and 15 grams.
- Edibles and drinks by THC content, commonly 500 to 800 milligrams per package.
That is why a state can hand you a full ounce of flower but only a few grams of wax. The flower cap and the concentrate cap are separate laws, not one converted into the other.
Flower limits in several legal states
- California: 28.5 grams
- Colorado: 1 ounce for adults, 2 ounces for medical patients
- Washington: 1 ounce
- Oregon: 1 ounce in public, 8 ounces at home
- Nevada: 1 ounce
- Arizona: 1 ounce for adults, 2.5 ounces for medical patients
- Illinois: 30 grams
- Michigan: 2.5 ounces in public, 10 ounces at home
- Massachusetts: 1 ounce in public, 10 ounces at home
- Maryland: 1.5 ounces
- New Mexico: 2 ounces
- Connecticut: 1.5 ounces
These figures change. Legislatures raise caps, regulators rewrite them, and ballot measures add new ones, so a number you read last year may already be stale.
Concentrates and edibles sit under their own caps
Concentrate limits are small by comparison because the product is potent. Nevada allows 3.5 grams, roughly an eighth of an ounce, and caps edibles at 800 milligrams of THC. Washington allows 7 grams of concentrate, 16 ounces of solid edibles, and 72 ounces of liquid edibles. California allows 8 grams of concentrate and 800 milligrams of THC in edible form. Illinois runs tighter at 5 grams of concentrate and 500 milligrams of edibles for adult-use customers.
If you buy a mix of flower, vape carts, and gummies in one trip, each category gets counted against its own limit rather than being added together into one total.
Medical patients usually get more room
Medical programs tend to allow larger amounts, and the gap is not small. Oregon medical cardholders can possess 24 ounces where recreational users get 1 ounce in public. Arizona medical patients get 2.5 ounces against 1 ounce for everyone else. Colorado doubles it, 2 ounces versus 1. Michigan and Maine grant medical patients higher in-home storage than adult-use buyers.
Getting those numbers means registering with the state and carrying valid documentation. A dispensary receipt alone does not put you under the medical cap.
Possession, purchase, and storage are three different numbers
The amount you may carry on the street, the amount a dispensary can sell you in one transaction, and the amount you may keep at home are separate rules. Colorado lets you possess an ounce but limits how much concentrate a shop can hand over per visit. Several states cap daily purchases per dispensary, which means walking to a second shop does not multiply your legal total.
Home storage limits are often the most generous. Massachusetts and Michigan both allow 10 ounces at home. Minnesota allows 2 pounds. Oregon allows 8 ounces. Those in-home allowances usually come with plant-count rules attached.
Where people get tripped up
- Federal land. National parks, forests, and military bases follow federal law, where possession is illegal no matter what your state says.
- State lines. Carrying cannabis from one legal state into another is a federal offense. Legal on both ends does not make the trip legal.
- Airports. TSA screens for security, not cannabis, but airport property and airspace fall under federal jurisdiction.
- Your car. An open container or a lit product is a separate violation in nearly every legal state, even if you are under the possession cap.
- Public consumption. Possessing an ounce is fine in most legal states. Smoking it on a sidewalk usually is not.
- Homegrown harvest. In most states, cured flower from your own plants counts toward your possession limit, and a single plant can easily produce more than an ounce.
How to confirm your own state's limit
Check the state cannabis regulator, not a dispensary menu or a forum post. Regulator pages list possession amounts by product type and get updated when the law changes. If you hold a medical card, look at the medical program rules separately, since they sit in a different section than the adult-use ones. And if you travel, look again at the destination, because the number that was legal at home rarely follows you across the border.