Generally, the United States does not allow "transit without a visa" (TWOV) in the traditional sense found in many other countries. Most international travelers transiting through a U.S. airport to a third country must possess either a valid C-1 transit visa or a B-1/B-2 visitor visa. However, citizens of countries participating in the Visa Waiver Program (VWP) can transit without a formal visa if they have an approved ESTA (Electronic System for Travel Authorization). Unlike many international hubs where you stay "airside," the U.S. requires all transiting passengers to clear Immigration and Customs Enforcement (CBP) at their first port of entry, even if their final destination is outside the U.S. This means you must have the legal right to enter the country. In 2026, ESTA remains the most efficient route for eligible travelers, but it must be obtained at least 72 hours before departure to ensure a smooth connection.