The best price found from United States to Vietnam is on March 12th, 2019, travelling with ANA. See more options, compare prices and book: search flights.
Vietnam has excellent domestic flight connections, with new routes opening up all the time, and very affordable prices (if you book early). Airlines accept bookings on international credit and debit cards. Note, however, that cancellations are quite common. It’s safest not to rely on a flight from a small regional airport to make an international connection the same day – travel a day early if you can. Vietnam Airlines is the least likely to cancel flights.
Jetstar Airways (www.jetstar.com)
VietJet Air (www.vietjetair.com)
Vietnam Airlines (www.vietnamairlines.com.vn)