Based on the M26 Pershing heavy tank, the T26E5 was designed as an assault tank to break through enemy defences. Its design is reminiscent of the idea behind the another success and popular tank, M4A3E2 "Jumbo" assault tank, which also had the goal of reinforcing armour to overcome enemy defences, which was very important at the time of 1945, when the T26E5 was produced. The T26E5 received significantly reinforced front armour and equipped with the 90 mm Tank Gun M3 L/53, same as in M26.