Francis Brent Mallo, of Loudon, Tenn., was arraigned Friday in 77th District Court.
The sexual assault allegedly occurred in his foster home in Evart. Prior to these sex charges, he was already lodged in the Osceola County Jail on similar, unrelated charges.
The investigation is ongoing, and police say there may be additional victims.
Anyone with information on this investigation is asked to contact Michigan State Police at the Mount Pleasant Post at 989-773-5951.