United Airlines SFO-SGN Ho Chi Minh City Vietnam has fares as low as $728 for travel in April and first week of May. Fares are $100 to $300 higher mid-May til late August when fares drop back down to $740.
Outbound flight is operated by Japan’s ANA via Tokyo and inbound is via two segments on Philippine Airlines to Manila, then Tokyo, then United Airlines from Japan connecting back to SFO.
United Airlines booking SFO-SGN roundtrip
Monday, April 20 – Monday, May 4, 2015
United and United codeshare flights on ANA are United K booking class.
Alternative Routing: Asiana Airlines SFO-SGN via Seoul $766 roundtrip
Fly Asiana Airlines SFO to Seoul and you may find a better 4-segment itinerary. Some Asiana routings allows overnight transit in Seoul at no additional cost. Yesterday, the same dates as the above United itinerary were available on Asiana for $766.
Asiana is not an option for a two-week trip April 20 to May 4 today, but here is a sample itinerary flying Asiana April 13 to May 10 if you want a long duration trip in Southeast Asia for $766. This fare allows you to fly in April and return in September if you want to be an expat abroad.
OneWorld JAL routing SFO-YVR-HND-SGN rt $732
You can even fly Air Canada to Vancouver and fly JAL via Tokyo Haneda to Vietnam for $732 with an online travel agency booking like CheapoAir.com. This itinerary lands you in Tokyo at 7am in the morning on the return with a midnight departure allowing for a full day wandering the city on a transit layover.
There are numerous airlines and different routings for flights from SFO to Vietnam for $730 to $780 with flight departures in April and early May before fares rise by $100 to $300 for summer months.