While a couple dozen states and some U.S. territories have legalized the usage of medical marijuana, and 18 states have legalized recreational cannabis usage, all types of usage remain illegal federally. But what does that mean in practice? And can you fly with marijuana?

State vs. Federal Legality

When state and federal laws exist in contradiction, federal law always triumphs, as established by the Supremacy Clause of the U.S. Constitution and many Supreme Court cases, including McCulloch v. Maryland. However, state laws legalizing cannabis usage have yet to be struck down because they violate federal statutes. Instead, the federal government is mostly ignoring addressing the conflicts that the passage of state cannabis laws may raise.

The federal government still classifies marijuana as a Schedule I drug, meaning they consider it to have a high potential for abuse and little to no medical applications. But besides legalizing medical marijuana out of sympathy for the patients it helps, states have plenty of financial incentive to legalize recreational cannabis thanks to hefty taxes they place on dispensaries.

Over the years, various bills to legalize marijuana at the federal level have been introduced, but none have passed. Multiple recently introduced pieces of legislation aim to change this, however.

Can I Fly With Marijuana Between States Where It’s Legal?

Nice loophole! But it’s not quite that easy. Though you may have heard it said that airports are federal property, or that somehow the air itself is “federal airspace,” most airports are actually owned by local or state bodies.

However, many airports receive federal grant funding for maintenance and improvement. This means that the airport’s owners, whether private companies or state governments, have additional obligations to the federal government and may be less lenient when it comes to breaches of federal law.

Is TSA Searching For Pot?

TSA has stated that they conditionally permit travelers bringing medically-compliant cannabis and cannabis products through security. However, if a TSA agent discovers these products in a traveler’s possession, “The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.“

Contradictorily, on the very same page the agency states that “TSA security officers do not search for marijuana or other illegal drugs, but if any illegal substance is discovered during security screening, TSA will refer the matter to a law enforcement officer.”

Are Those ‘Drug Dogs’?

No, the K9 units you see sniffing around at the airport are likely not there to search travelers for marijuana or other illicit substances. While the dogs are certainly capable of detecting cannabis, these units are mainly tasked with explosive detection, so Fido probably won’t snitch on you — he’s got a more important job to do!

To Bring or Not to Bring

Confusing enough yet? Marijuana laws, statutes, and policies have become so convoluted in this kind of situation that it’s nearly impossible to predict how tolerant the application of these rules will be in any individual case.

If you’re planning on taking the risk and bringing cannabis on your next airport trip, you might want to add one more thing to your packing list just in case: a lawyer’s name and contact information.