Yes, a 14-year-old can fly alone, but they fall into a specific transitional category that varies by airline policy. Most major carriers, such as American Airlines, United, and Delta, require children aged 5 to 14 to use their mandatory Unaccompanied Minor (UM) service. This service involves a fee (typically $150 per flight) and ensures that a staff member escorts the teen through security, monitors them during the flight, and hands them off only to a pre-authorized adult at the destination. For 14-year-olds, this service is often the final year it is strictly required; once a child turns 15, many airlines allow them to travel as a "Young Passenger," making the UM service optional. It is crucial to check the specific airline's 2026 rules, as some budget carriers do not offer UM services at all and may prohibit anyone under 16 from flying without an adult. Additionally, if the flight is international, a 14-year-old traveling alone will almost always require a notarized Letter of Consent from their parents to pass through immigration without delay.