Evisa:

For United States passport holders coming to Vietnam for tourism purposes, visiting relatives, business activities…and have a stay of less than 3 months
     – Passport is required with at least 6 month of validity from the expected date of entry and at least 2 blank page
– You need to provide a portrait photo (Clear quality photo, Looking straight, without glasses)

Tourist Visa:

For United States passport holders coming to Vietnam for tourism purposes
     – Passport valid for at least 6 months from the date of entry to Vietnam;
– Passport with at least 02 blank pages.

Business Visa 

For United States passport holders coming to Vietnam for business purposes and have a stay of less than 3 months

– There is a valid passport, limited to at least 6 months from the date of entry to Vietnam, and at least 02 pages.
– There is a guarantee company and is operating legally in Vietnam.
– Visa applicants must be recruited / invited to work / work / visit…. legitimate by the guarantee company.

NOTES:
– Travelers who transit through Vietnam airport should check the airlines for Vietnam visa requirements.
– Travelers directly visiting Phu Quoc Island, either by boat or airplane from a country other than Vietnam, and stay for less than 30 days are not required to have Vietnam visa.