BIG NEW: 1 year tourist visa for USA passport
From now on (26/08/2016), Vietnam tourist visa for all USA citizen to Vietnam will be automatically and mandatory converted into a 1 year tourist multiple entries visa with maximum 90 days duration allowed of each visit. It means you will have to do visa run (or in-country visa extension) each 90 days if you plan to stay Vietnam long term.
Circular No.190/2012/TT-BTC
AMENDING AND SUPPLEMENTING THE CIRCULAR NO.66/2009/TT-BTC, OF MARCH 30, 2009 OF THE MINISTRY OF FINANCE STIPULATING THE REGIME ON COLLECTION, REMITTANCE, MANAGEMENT AND USE OF FEES ON PASSPORTS, VISAS AND PAPERS ON ENTRY, EXIT, TRANSIT AND RESIDENCE IN VIETNAM
Xinvisavietnam.com is legitimate website, and one of the most well known in-country visa providers for ensuring appropriate paperwork and authorizations services for tourist and expats who are in or wish to enter Vietnam