Calum MacLeod struck 46 at the top of the order while captain Kyle Coetzer's unbeaten 35 off 24 deliveries eased the Scots to their victory target of 134 with seven balls to spare in Dubai.
The United States had earlier been restricted to 133 for seven and that was largely thanks to the efforts of opener Steven Taylor, who smashed four fours and three sixes in his 51-ball 55.
Iain Wardlaw was the pick of the attack with three for 25 in Scotland's penultimate warm-up match before they start their World Twenty20 qualifying campaign against Bermuda at the Sharjah Cricket Stadium on Friday.
Scotland will be hoping to reach next year's World Twenty20 in Bangladesh, with six countries to qualify for the expanded 16-team tournament.
- Sports & Recreation
- Kyle Coetzer