In 2026, the gender listed on your boarding pass must match the gender on your government-issued ID for security verification. This is a requirement of the TSA's "Secure Flight" program, which uses your full name, date of birth, and gender to cross-reference passenger lists with watchlists. While a discrepancy might not always prevent you from passing through the initial document check, it can lead to delays or "secondary screening" at the gate if the airline's manifest doesn't sync with your ID. For transgender or non-binary travelers, the TSA has updated its protocols to be more inclusive; many airlines and the TSA now accept "X" gender markers. If your ID says "X" but your ticket says "M" or "F," you should contact the airline to have it corrected before arrival. The goal is to ensure that the person standing at the checkpoint is the same person who purchased the ticket, and matching biographical data—including gender—is a key part of that identity authentication process.