If you wish to enter Taiwan as a tourist or short-term visitor (less than 90 days), you do not need a visa. No extensions or changes of status are permitted. Your U.S. passport must be valid throughout your intended length of stay and you must have a confirmed return or onward air ticket.
If you plan to stay longer than 90 days or plan to work, you need a Taiwan visa prior to traveling. Visit the Taipei Economic and Cultural Representative Office (TECRO)’s website for the most current visa information.
HIV/AIDS restrictions. Taiwan lifted its ban on entry, stay, and residence of foreigners living with HIV on February 4, 2015. Taiwan generally does not ask you about your HIV status unless you are applying for a resident visa which requires a health certificate that will indicate whether you are HIV positive.
Taiwan and the United States both allow dual nationality. If you have Taiwan/U.S. dual nationality, you must enter/exit Taiwan on your Taiwan passport and enter/exit the United States on your U.S. passport.