All 26 are accused of evading tests but say there was an administrative error.
The list includes Fabrizio Donato, triple jump bronze medallist at London 2012, and Andrew Howe, who took silver in the long jump at the 2007 World Championships.
They will face trials at the Italian Olympic Committee's anti-doping court, with rulings expected next year.
Five of the 26 athletes have already qualified for next year's Olympic Games in Rio de Janeiro, Brazil.
Italy's Olympic chiefs want 26 of the country's athletes banned for two years over alleged doping offences.