The 29-year-old was caught in October 2008 when a sample taken during that July's Tour de France was shown to have contained CERA, a variant of banned blood-booster EPO, which is a performance-enhancing drug.
His suspension by the sport's governing body the International Cycling Union (UCI) expired on Saturday.
The German rider had wanted to race in Saturday's Giro del Veneto in Italy for his new Italian team Miche, but said: "Formalities could not be settled in time".
Schumacher, a former Gerolsteiner rider, is now expected to race at the Giro della Romagna in Italy on September 5.