Here's the gist of the MMJ-Friendly California Airports:
LAX (with possibly Ontario, Van Nuys, and Palmdale airports): CA State-issued Identification Card Only
Oakland: State-issued Identification Card OR Immediately Verifiable Valid Medical Marijuana Recommendation
SF: State-issued Identification Card OR Immediately Verifiable Valid Medical Marijuana Recommendation
As a medical marijuana patient with a state-issued ID card (the one issued by your County Department of Public Health) that is in possession of under 8 ounces (or 6 plants, if they don't look at you weird), in your carry-on luggage or on your person only, there is likely little-to-zero trouble that you could get in by going through security in Los Angeles International (LAX), San Francisco International (SFO), or Oakland International Airport (OAK). The general procedure is that you check-in to your flight as normal -- no need to alert the airline or TSA ahead of time -- and then place your items through the scanner. Upon discovery of such contraband, the TSA refers such individual to the state or local police that have jurisdiction at that airport. Most airports -- and all of the airports above -- are governed by state or local police, which enforces state law (and not federal law). California's Proposition 215 in 1996 (and further with SB420 in 2003) operate with the understanding that, in general, medical marijuana patients in the state of California are still subject to arrest like anyone else unless the recommendation has been verified with the state (through the issuance of the state-issued card, per CA Health and Safety Code 11362.71).
However, Oakland and San Francisco are two exceptions to that rule, at least when it comes to airport policy. Oakland International Airport's policy is more clear, thanks to the Alameda County Sheriffs Department, which as long as such individual can establish that he or she is a qualified patient or a primary caregiver based upon the information at hand (including a phone call to the doctor), no person shall be hassled by police, nor report to federal authorities or to the destination city. As for San Francisco International, while I cannot find the written policy, SFPD claimed that any individual that has a medical defense would go through a similar verification procedure as Oakland International. I attempted to test such policy in San Francisco; however, the TSA didn't flag the bag with the medicine in it, and thus the airport police weren't called (yeah, they didn't notice the sack of weed in my bag, and I was literally the only person they were screening at the time).
Other airports in CA aren't so friendly, such as San Jose. Although they'll let any person with an identification card enter the airport with medical marijuana, the state authorities will file a report with federal authorities, which will choose whether or not to pursue legal action (under federal penalties). As a general precaution, this procedure should be expected in any California airport, with obvious exception for the three listed above.
If you're looking for MMJ-friendly airports in other areas besides California, and can establish a medical defense in accordance with the respective state laws, people have found little issue traveling with MMJ out of Washington's Sea-Tac (Seattle) and Montana (pre-2011 law change), and places like Canada allow you to vaporize in airports.
Bottom line -- If you're a California resident, get a state-issued identification card (ranging from $100-150, valid for one year), and you won't be cited, arrested or miss your flight if it's in your carry-on (not checked!) at Los Angeles, San Francisco or Oakland. You will likely not encounter issues on the other side, unless both a drug-sniffing dog points you out (very unlikely, as the dogs you generally see at airports are bomb-sniffing) and it's illegal to possess MMJ in your destination state (or via point). If you travel through SFO or OAK without a verifiable medical marijuana recommendation or identification card, you'll be cited under state law for marijuana possession ($100 fine + court costs), the police will confiscate your stash, and you can prove your defense later in court.
Oakland -- Got Pot? It's Legal to Take It on the Plane in Oakland | Drugs | AlterNet
San Francisco & San Jose -- ASA : Medical marijuana patients can travel with pot from SFO, other Bay Area airports
Los Angeles -- MedicalMarijuanaPolicies
Washington -- Man Gets Out Medical Marijuana At TSA Checkpoint, Gets Through - Toke of the Town
Canada -- Canada: Marijuana Patients Allowed To Vape In Airports, Planes - Toke of the Town
Montana -- Report: Medical Marijuana Now Allowed In Airports - Toke of the Town
Edited by GreenDevil420, 09 May 2012 - 01:12 AM.