I am a US Citizen and my current 3 month Vietnam tourist visa expires on December 27th. I am currently in Europe for two more weeks before returning to Ho Chi Minh on December 22nd. Is it possible to apply for a new 90 day tourist visa to Vietnam for when I arrive on December 22nd and have that last for 90 days or is it necessary for me to make a Visa run December 26th-27th to get a new visa? Ideally I would like to avoid the Visa run if possible since I will be flying in from Europe anyways.
You can apply for a new tourist VISA and it will just cancel out your current one. This can be done online and you'll be able to pick up your VISA on-arrival at the airport. Typical fee is $25 cash.