As we are currently in 2026, the rules for Turkish transit have stabilized following some changes in late 2023 and 2024. For a pure airside layover (staying within the international transit area of Istanbul Airport), most nationalities, including U.S. and EU citizens, do not need a visa. You can simply walk from gate to gate. However, if your layover is long and you want to exit the airport to visit the city, you must have an e-Visa (if your nationality requires one). In early 2024, Turkey implemented a visa-free regime for tourists from the USA, Canada, and several other nations for stays up to 90 days, meaning as of 2026, U.S. citizens no longer need an e-Visa for short visits or city layovers—you just need a valid passport. If you are of a nationality that still requires an e-Visa, you should apply at least 48 hours in advance at evisa.gov.tr for a fee of around $20–$50. Always check your specific passport requirements, as some "transit" passengers from certain African or Middle Eastern nations may require a "Transit Visa" even for airside stays.