The M44 was a self-propelled howitzer designed as a replacement for the World War II-era M41 which was the main 155-mm SPG fielded by the US in the late 1940s. The M44 featured many common components with the M41 light tank that was in development at the same time, and was characterized by an all-welded hull with the engine and transmission at the front and a fighting compartment which housed the entire crew fitted in the rear. A spade was also fitted to the rear hull for stability when firing. Armament consisted of a 155-mm M45 howitzer which had a maximum range of 14.6 km with an average firing rate of one round per minute, with elevation and traverse being hydraulic. A .50-in Browning machine gun could be fitted for anti-aircraft defense but there was no NBC protection nor amphibious capability. Faults in early production units resulted in the M44 missing out on the Korean War and it was phased out of US Army service in the early 1960s once the M109 was introduced. Export clients included Belgium, Germany, Greece, Italy, Japan, Turkey, and the UK. Turkish units remained in service until the 1990s.

The prototype T99 began development in 1947. It began incorporating elements from the T41E1 light tank resulting in the T99E1, which had a fully enclosed fighting compartment. Mass production of the prototypes began before faults in the fume ventilation system were discovered and this resulted in further modification into the T194 which introduced the open top, entering service as the M44. The sole variant was the M44A1 which introduced a fuel-injected engine. The M44T was a Turkish variant equipped with Rheinmetal L/36 howitzers which greatly expanded range as well as a MTU water-cooled diesel engine.