For working Siberians, something equivalent to a Science Diet Performance is in order. For Siberians that go for walks and hikes, a Maintenance formula is usually best. Consult your breeder and veterinarian for advice. One other thing worth mentioning here is how long to feed puppy food. Some research indicates that feeding puppy food for too long can increase the incidence of hip dysplasia in dogs that are susceptible to it.
Some breeders start feeding adult food very soon.
Even though the Siberian is not fully mature until 18 months, most people gradually switch to adult dog food at the 8-10 month time frame. Again, this is something to discuss with your breeder and veterinarian. Housing Siberian Huskies are happiest when they can share in family activities. The best arrangement is one in which the dog can come in and out of the house of its own free-will, through a dog door. If a dog door is not possible, then training the dog to go to an outside door to be let out is also very easy to do.