In 2026, for the vast majority of domestic and international flights, it does not matter if your middle name is missing from your ticket, as long as your first and last names match your government-issued ID exactly. TSA and international border authorities primarily look for consistency in the "Given Name" and "Surname" fields. Most airline booking systems are designed to handle names without middle initials or full middle names because many global passports do not format names the same way. However, if you are a member of a Trusted Traveler Program (like Global Entry or TSA PreCheck), your middle name should ideally be on the ticket to ensure your "Known Traveler Number" (KTN) validates correctly. If you discover the omission after booking, there is usually no need to pay a name-change fee; simply ensure your "Secure Flight Passenger Data" (which you enter during check-in) matches your passport's machine-readable zone (MRZ) precisely.