The suspension stems from Bell pleading no contest to drunk driving and hit and run charges in August for an incident that took place in California last September.
Bell will serve six months in a California county jail at the end of the season.
The 27-year-old will not be paid during his suspension and will need the approval of both the NHL and the NHLPA in order to be reinstated after consultation with program doctors.
Toronto opens training camp on September 13th. The NHL says that the program doctors will make a "clinical determination" about which training camp activities he'll be allowed to participate in.
The Maple Leafs acquired Bell in June along with goaltender Vesa Toskala in a trade with the San Jose Sharks.