This question already has an answer here:
I read a lot here about resetting ESTA by going outside of US and then returning, but I still want to make sure I get it right. My 90 days will be over in October. I am planning to travel to Dominican Republic in September and then in October enter the US again.
Will it reset my ESTA for another 90 days?
One of my friends did so and he says it works, but I keep reading about an "adjacent islands zone" and am a bit worried.