The 25-year-old penned terms with the American outfit after his last team Spidertech folded.
Fairly was with Garmin's development team in 2009 and 2010 when he briefly rode as a stagiaire for the World Tour team.
He quit to join HTC in 2011, but soon moved on to Spidertech after HTC also went under.
“I’m very excited to be joining Garmin-Sharp-Barracuda," the Texan said on the team’s website. "I feel like I’m ‘re-joining’ them, as I grew up in their development team. I was excited when Jonathan (Vaughters) offered me the opportunity to come back."