Evgeny Novikov and Thierry Neuville will contest all 13 rounds of next year's World Rally Championship with M-Sport.
Novikov, 22, and Neuville, 24, join Mads Ostberg and Nasser Al-Attiyah at the team. Novikov finished sixth in this year's championship and also became the youngest man to stand on a WRC podium when he finished third on the road - which became second when Mikko Hirvonen was excluded - in Portugal.
Neuville meanwhile has claimed 11 stage wins across the 20 WRC events he has entered, with his fourth place in this year's Rally France his best result.
M-Sport boss Malcolm Wilson believes both drivers will impress in 2013 despite their young age and relative inexperience.
"Evgeny [Novikov] and Thierry [Neuville] are young, but they have both shown some real maturity this year - combining obvious speed with a determination to finish all of the events and gain as much knowledge of the stages as possible," Wilson said.
"Both have regularly challenged the factory drivers, and their 2012 results were thoroughly deserved. I am confident that both drivers have more to prove and that we will see more impressive performances from them in 2013.
"We have a young team for next year, but this by no means detracts from their ability to produce some strong results.
"All of them, Mads [Ostberg], Evgeny [Novikov] and Thierry [Neuville], proved their worth in 2012 and, with guidance from Nasser [Al-Attiyah], they can all be fantastic ambassadors for M-Sport and the WRC."