Emerging talent Brandon McNulty will make the step up to the WorldTour for 2020, aged just 21.
The American has been tipped as a future general classification star and has already showed himself in some big races.
McNulty, a junior world time trial champion, makes the move from his current US Continental team Rally Cycling to UAE Team Emirates on a three-year deal.
General manager of UAE Team Emirates, Joxean Matxin, said: “Brandon is a world-class talent, with two key qualities that few riders his age possess – the ability to combine both climbing and time trialling at a high level.
“Throughout his career, he had demonstrated steady growth and a remarkable consistency in reaching his objectives.
“Many teams wanted to sign Brandon and we are very pleased to have secured the opportunity to welcome him into our team.”
McNulty, from Phoenix, Arizona, might be best remembered for the heart-breaking end to a solo attack at the 2018 Dubai Tour.
Then 19, McNulty had made it into the breakaway on stage four and rode away solo on the penultimate climb only to face the wall of the Hatta Dam climb to the line, which hits 17 per cent gradient.
McNulty cramped on the climb and was caught by the peloton in the final 20 metres, denying him what would have been the biggest victory of his career.
But he has been building a strong palmarès for such a young rider, winning the Giro di Sicilia this year and taking seventh overall at the 2018 Tour of California.
McNulty said: “My initial feelings about joining the WorldTour are pure excitement. I’ve been patient with my development over the last few years and now I can say that I feel I am ready to make the jump and I’m excited for the challenges to come. I’d like to thank my current team.
“I chose UAE Team Emirates because their interest in long-term development in me as a rider and also the team. There’s obviously already a very strong crop of young riders on the team already, which is exciting for the future.
“My main goal is to become the best rider that I can be. If I can do that then I think some nice results will come.”