Due to the fact that it used a casemate rather than a turret for holding the gun, the T28 seemed more like a self-propelled gun than a tank, and it was officially known as a self-propelled gun, the T95 Gun Motor Carriage, in 1945, and it was treated as so in every way - except that it fired directly at its target rather than a ballistic arc. However, in June 1946, the T95 GMC was redesignated as the T28 super heavy tank again. Many argue that it was neither, but a tank destroyer, like the Jagdpanzer.
The two T28s built underwent trials at the Aberdeen Proving Grounds and at Fort Knox unti 1947. One T28 was heavily damaged by an engine failure in 1947, and the other was sold for scrap. The T28 never went into service. The reason was twofold; there were similar heavy tanks with a near-identical gun and extremely heavy turrets, namely the T29 and the T30, and by the time the T95 would be ready, the Second World War was already over.
In 1974 the sole remaining T28 was discovered abandoned at a back field of Fort Belvoir, Virginia. It is unknown how it had survived the previous 27 years, but it was repaired and put on display in the Patton Museum of Cavalry and Armor in Kentucky. It was then prepared for its journey to a new home at Fort Benning, Georgia.