- T-28 Model 1934 (German designation: T-28A) – main production model with the same machine gun turrets, and similar main turret, with the KT-28 76.2 mm gun, as the T-35 heavy tank. During the production minor changes were introduced, such as the addition of a grille above the rear fan in 1935, two hatches replacing the larger one on the turret and the addition of a ball mount for the rear machine gun in 1936.
- T-28 Model 1938 (T-28B) – version with the improved L-10 76.2 mm gun (from 16.5 to 26 calibres). Some older tanks were also backfitted with spare L-10 guns. The rod antenna replaced the horseshoe in early 1939.
