US airline trade group Airlines 4 American confirms that it has “approved a new international standard that will allow for ‘unspecified’ and ‘undisclosed’ in addition to ‘male’ or ‘female.’”
Effective June 1, 2019 this accommodates passengers who have an ‘X’ on their IDs for gender. This is currently an option for state IDs from Arkansas, California, Colorado, Minnesota, Oregon and Washington, D.C.
Delta is not a part of the major airline lobby shop, they stopped paying dues when want they wanted from the government diverged from that of some of their peers. However they also confirm that they’re “planning to offer a non-binary gender option during the booking process.”
I don’t expect this all to be ready across the board on June 1 since carriers have to separately update their booking platforms.
This strikes me as a matter of respect rather than functionality (it’s awkward to force people into a box that their state government doesn’t require). I’m unaware of any reported issues with TSA declining to permit passengers whose IDs show a gender that differs from what’s in the secure flight data of their reservation from passing through a security checkpoint. Apparently the data field just requires a single chacter but cannot be left blank.
Update: United says they’re mere weeks away from rolling this out, and offers additional details:
As part of our commitment to inclusion, we want to ensure all of our customers feel comfortable and welcome no matter how they self-identify, which is why we will begin offering our customers the ability to select the gender with which they most closely identify during the booking process. Beginning in the coming weeks, customers will be able to identify themselves as M(ale), F(emale), U(undisclosed), or X(unspecified), corresponding to what is indicated on their passports or ID. Also, customers who do not identify with a gender will have the option of selecting “Mx.” as a title. We are excited to share this next step as we continue to break down barriers to promote inclusion.