Flying with medical marijuana between states that have reciprocal agreements has been legal for awhile now. I even know dozens of people that have flown with medical marijuana from their home state to states that have no medical marijuana program, and for the first half of the trip, it’s perfectly legal. This is because TSA does not enforce marijuana laws.
TSA’s policy is to refer any marijuana cases to local law enforcement. If you are in a medical marijuana state, airport or otherwise, your card protects you. So for instance if you are an Oregon medical marijuana patient flying from Portland, Oregon to say Tennessee, the whole time you are in the airport in Portland, including security, you are legal. The local police that TSA would be calling would look at your card, check your supply, and assuming everything is legit, you would be on your way. Of course, it begs the question ‘what happens when I land in Tennessee?’ If the Portland police or TSA notified the other side, you would likely be greeted by local law enforcement in Tennessee…
States like Arizona recognize out of state cards, so flying from Oregon to Arizona with medical marijuana is perfectly OK. But how does this work with recreational, legal marijuana in the states of Colorado and Washington? Westword recently posed that question to TSA, and here was their response:
“TSA security officers do not search for marijuana or other drugs. In the event a substance that appears to be marijuana is observed during security screening, TSA will refer the matter to a law enforcement officer.
Whether or not marijuana is considered “medical marijuana” under local law is not relevant to TSA screening because TSA is governed by federal law and federal law provides no basis to treat medical marijuana any differently than non-medical marijuana.
Even if an item is generally permitted, it may be subject to additional screening or not allowed through the checkpoint if it triggers an alarm during the screening process, appears to have been tampered with, or poses other security concerns. The final decision rests with TSA on whether to allow any items on the plane.”
So to sum up, ‘the final decision rests with TSA’ which is ‘TSA will refer the matter to a law enforcement officer,’ which will be the local police. Seattle police and Denver police are not going to arrest anyone for personal marijuana possession anymore, so in a roundabout way, the answer is yes, you can fly between Washington State and Colorado with one ounce of marijuana legally. You run the risk of harassment by security, but at the end of the day, what you are doing is not illegal.