The move erases the Saturday deadline for Armstrong to either send the case to arbitration or accept sanctions from USADA, which would likely include a lifetime ban from cycling and other sports along with stripping the Tour titles he won from 1999-2005.
Armstrong this week sued in U.S. District Court in Austin to block the case from moving forward, arguing that USADA's arbitration process violates his constitutional rights and that the agency doesn't have jurisdiction over the alleged doping violations.
Granted the extension, Armstrong lawyer Tim Herman withdrew a request Wednesday for a temporary restraining order while Judge Sam Sparks reviews the complaint and a request for an injunction.
USADA accused Armstrong in June of performance-enhancing drug use throughout much of his career. Armstrong insists he is innocent and says he never failed a drug test.
Travis Tygart, USADA's chief executive, predicted Armstrong's lawsuit will be dismissed.
"USADA believes this lawsuit, like previous lawsuits aimed at concealing the truth, is without merit and is confident the court will continue to uphold the established rules which are compliant with federal law and were approved by athletes, the U.S. Olympic Committee, and all Olympic sports organizations," Tygart said in a statement.
Johan Bruyneel, the manager on Armstrong's winning teams, who also has been charged, is not covered by the 30-day extension, even though USADA had consolidated their cases, USADA spokeswoman Annie Skinner said.
Bruyneel still faces a Saturday deadline to challenge the charges or be sanctioned, Skinner said. Bruyneel, who manages the RadioShack-Nissan-Trek team, skipped this year's Tour de France because of the investigation.
RadioShack-Nissan-Trek team spokesman Philippe Maertens declined to comment, and said he was "100 per cent sure" that Bruyneel didn't want to comment.
Three former medical staff members and consultants on Armstrong's winning teams received lifetime bans from sport from USADA on Tuesday.
Luis Garcia del Moral was a team doctor; Michele Ferrari a consulting doctor; and Jose (Pepe) Marti a team trainer for Armstrong's U.S. Postal Service and Discovery Channel squads. All had been accused by USADA of participating in a vast doping conspiracy on those teams during part or all of Armstrong's seven Tour victories.
There was no indication that those three co-operated with the USADA investigation before receiving the maximum punishment.
Another team doctor, Pedro Celaya, also has been charged. A USADA statement announcing the penalties against Moral, Ferrari and Marti suggested Celaya chose to send his case to arbitration.