I am holding a U.S. passport and have traveled by ground into Laos many times; however, this is my first time flying into Laos. Just wanted to make sure that I can get a visa on arrival or do I need to get a visa from the Laos embassy in advance.

Many thanks.

I think yes. I did exactly that some years back. I don't know the current cost. I suggest bringing exact change in US dollars to pay for the visa.