The Sturmgeschutz IV (StuG IV) (Sd.Kfz. 167) was a German assault gun variant of the Panzer IV used in the latter part of the Second World War. It was identical in role and concept to the highly successful StuG III assault gun variant of the Panzer III. Both StuG models were given an exclusively tank destroyer role in German formations and tactical planning in the last two years of the war, greatly augmenting the capability of the dwindling tank force available to the German army on the Eastern and Western fronts.
The Sturmgeschütz IV resulted from Krupp's effort to supply an assault gun. As Krupp did not build Panzerkampfwagen IIIs, they used the Panzerkampfwagen IV chassis in combination with a slightly modified Sturmgeschütz III superstructure. The first known proposal for a Sturmgeschütz on the Panzer IV chassis is in Krupp drawing number W1468 dated February 1943. This initial drawing unitized the outdated Sturmgeschutz Ausf. F superstructure on a Panzer IV chassis. This proposal had a sloped front superstructure with a combat weight of 28.26 tons. Krupp abandoned it in February 1943 because it was too heavy. Plans for the StuG IV were halted.
During the Fuhrer Conference of 19 to 22 August 1943, after the Battle of Kursk, Hitler had seen reports of the StuG III outperforming the Panzer IV when used in an infantry support role and tactical defence. Convinced that a tank-hunter version would be superior to the tank version, Hitler planned to switch Panzer IV production to "Panzerjager IV" production as soon as possible. It was to mount the same 7.5 cm L/70 used for the Panther. Another manufacturer, Vomag built a prototype Panzerjäger IV with 7.5 cm L/48 gun and demonstrated it on 20 October 1943. It was later re-designated as Jagdpanzer IV Ausf. F. As the Jagdpanzer IV was already being produced by Vomag, the StuG IV may not have materialized, had it not been for the major disruption of StuG III production, and the scarce supply of the 7.5 cm L/70 gun designated for the Jagdpanzer IV.