T-Mobile claim they have received a four-year racing licence from the International Cycling Union.
Ullrich has claimed he is innocent of any accusations of doping
The German outfit was rocked by a series of doping scandals in the run-up to the Tour de France last month.
But they have reshaped their team after sacking Jan Ullrich and Oscar Sevilla after both riders were linked to the ongoing drugs probe in Spain.
"This is an important step for both our team and the ProTour," said new team manager Bob Stapleton.
"The UCI immediately recognised the value that T-Mobile brings to cycling and respects the team management's commitment to clean and fair sport.
"We are making good progress as a team and are happy for this important validation."
Stapleton, who replaced Olaf Ludwig, called the decision to grant T-Mobile a new licence "a first step in the ongoing restructuring of the team".
T-Mobile fired Ullrich on 21 July.
The 1997 Tour de France winner had been considered a leading contender for this year's race.
But the German was forced out after Spanish media reports said his name turned up on a list of 56 cyclists who had contact with a Spanish doctor charged with doping.
"Now armed with the licence, we can approach contract talks with riders very differently," said sports director Rolf Aldag, a former T-Mobile rider who ended his career last year.
"I'm convinced that we are assembling a strong team, capable of meeting our expectations, and not just on the bike."
According to T-Mobile's Web site, the UCI also extended the licence for the Spanish team Caisse d'Epargne-Illes Balears.