The United States Anti-Doping Agency, the organisation whose investigation into the US Postal Service team led to Lance Armstrong's belated confession, on Thursday announced Klier had accepted the suspension following use of blood transfusions, erythropoietin (EPO), human growth hormone and cortisone from 1999 to 2006.
From 2001 to 2008, Klier rode for Team Telekom alongside Jan Ullrich, who recently admitted to doping.
The 37-year-old Klier retired in May before becoming a team director with Garmin-Sharp.
His period of ineligibility began on August 12, and all results prior to July 21, 2005 have been removed from the record books. Klier apologised for his indiscretions and insisted he stopped doping prior to joining the Garmin-Sharp team in 2011.
The team is run by Jonathan Vaughters, a former doper, ex-team-mate of Armstrong and now fervent anti-doping campaigner, and is renowned for welcoming reformed drug cheats.
In a statement issued by Slipstream Sports, the parent company of the Garmin-Sharp team, Klier said: "I have been involved in professional cycling for 17 years, and for those 17 years cycling has been my life.
"Some of my best memories and moments happened on my bike, and some of my worst too.
"Along the road to the top of the sport, many years ago, I chose the wrong path, and I have been very sorry for it ever since.
"I accept responsibility for the mistakes I made in my past and the punishment that comes along with them."
Slipstream Sports added in a statement: "We support Andreas for telling the truth about his past, a past that pre-dates Slipstream Sports by years, and accepting the consequences that come along with it.
"Nothing can erase what happened in cycling's history, but we can learn from it.
"We can look at the crop of young athletes coming up not just on our team but on other teams and have confidence that the future of the sport is here.
"Cycling has never been cleaner and we will work, every day, to help it continue to progress."