Tom Danielson, George Hincapie, Levi Leipheimer, Christian Vande Velde and David Zabriskie all agreed to serve six-month suspensions as part of a plea bargain to provide sworn testimony to the United States Anti-Doping Agency.
USA Cycling praised the cyclists for confessing to their own transgression but said the bans would stand and their results annulled during the period they admitted to cheating.
"As a result of their testimony in the Lance Armstrong investigation, USA Cycling will enforce these sanctions and is currently reviewing the impact of the sanctions on historical results," said Steve Johnson, chief executive of USA Cycling, in a statement.
"More importantly, I would like to personally acknowl-edge the extraordinary courage of these riders who placed their careers on the line in order to come forward with their experiences of past doping practices."
The five riders, all former team-mates of Armstrong, were among 26 people who testified against the seven-time Tour de France winner, who was banned for life and stripped of his titles last month after deciding not to fight doping charges laid against him.
Armstrong has maintained his innocence, with his lawyers describing the USADA investigation as a "witch hunt", despite having been branded a cheat by dozens of people in the sport.
A USADA report, released on Wednesday, said it had "undeniable evidence" that Armstrong was one of the ringleaders of a sophisticated and elaborate doping programme that took him to the top of the cycling world.
"While this is an extremely difficult time for the sport, I believe that riders of today understand that doping is intolerable, that it will be discovered, and that a decision to engage in doping in any form is senseless," Johnson said. "As a result, I am greatly encouraged that the culture of professional cycling has changed and the future of our sport has never been brighter."