The short answer: there is no fully legal way to fly with cannabis in the US in 2025. Cannabis is still a Schedule I drug under federal law, and every flight crosses federal airspace. That said, TSA says its officers do not search for marijuana, and a few airports have local policies that let adults carry small amounts. The practical outcome depends on where you start, where you land, and how much convenience you're willing to trade for risk.
What "legal" means at 30,000 feet
State legalization stops at the airport curb in most places. Federal law applies in the air and at TSA checkpoints, which are federal screening zones. Carrying cannabis from one legal state to another is still technically interstate trafficking. I've never seen a federal agent at a TSA bin, but the law is the law, and local police make the call when something turns up.
The TSA reality check
TSA's own policy says officers do not search for marijuana or other drugs. If they find it during routine screening, they call local law enforcement. What happens next is up to the airport's city or county. In Los Angeles, airport police allow passengers 21 and older to carry up to 28.5 grams. Denver bans cannabis on airport property, and amnesty boxes sit near checkpoints for disposal. Las Vegas has similar boxes. So the "legal" part is really a patchwork of local rules, not a federal green light.
Convenience is the real variable
Here's where the convenience question bites. If you're flying from LAX to Seattle with a sealed vape cartridge in your carry-on, the odds of a problem are low, and the payoff is not scrambling for a dispensary on arrival. If you're flying from a legal state into a prohibition state, or through a hub with strict airport rules, the same cartridge becomes a liability. I look at three things: origin airport policy, destination possession law, and whether the trip is domestic. International is a hard no. US customs and foreign border agents do not share TSA's hands-off posture.
- Domestic only. Never fly internationally with cannabis, even to Canada or Mexico.
- Check the airport, not just the state. Denver restricts; LAX permits small amounts.
- Stay under the destination state's possession limit, which can be as low as 1 ounce.
- Keep it sealed and odor-proof. Flower smells. Edibles and vape carts travel easier.
Packaging and quantity that reduce friction
Put cannabis in your carry-on, not checked luggage, if you're going to bring it. If a checked bag gets flagged, you're not there to answer questions, and the bag gets pulled. Carry-on keeps you in the conversation. Use original packaging with labels, keep quantities small, and don't mix it with anything else that could trigger a secondary search. A half-empty water bottle or a lithium battery will get your bag opened faster than a sealed gummy pack.
What not to do
Do not mail cannabis. Do not drive it across state lines as a workaround. Do not bring it to a federal facility, a national park, or a military base. Do not assume a medical card travels. Some states honor out-of-state medical cards, most do not, and federal law does not recognize any of them. And do not argue with a TSA officer or local police about state law. The conversation is not the place to litigate Schedule I.
The convenience test
Ask yourself one question: if the cannabis gets found, am I okay with the local outcome? In LAX, that outcome is usually nothing beyond a referral. In Denver, it's confiscation and a possible citation. In a prohibition state, it could be arrest. If the answer is no, buy at your destination. Dispensaries are everywhere in legal states now, and pre-order pickup takes less time than a checkpoint conversation. Convenience is the deciding factor only when the risk is priced in.