Dr. Luis Garcia del Moral, Dr. Michele Ferrari and Jose "Pepe" Martí were all banned by the USADA, the group announced Tuesday.
"Permanently banning these individuals from sport is a powerful statement that protects the current and next generation of athletes from their influence, and preserves the integrity of future competition," USADA CEO Travis T. Tygart said in a statement.
The three are accused of conducting transfusions and administering other performance enhancing drugs to Armstrong and the rest of his team. The three did not contest the accusations.
The USADA said the three trainers are part of "one of the worst and deepest doping conspiracies the world has ever seen."
Armstrong maintains that he never used performance enhancing drugs during his bicycling career. On Monday, a judge dismissed Armstrong's lawsuit against the USADA, which he filed in response to the investigation.
ABC News contributed to this report.