Mass production began in September 1941, at Omsk Aircraft Factory Number 166, with the first aircraft reaching combat units in March 1942. Modifications were made based on combat experience, and Plant Number 166 built a total of 80 aircraft. The AM-37 engine was abandoned to concentrate efforts on the AM-38F for the Il-2, which required Tupolev to redesign the aircraft for an available engine. Modifications of this bomber to the ASh-82 engine as well as improving the general design for simpler manufacturing took well into 1943 with production restarting in late 1943. Wartime production of the new variant was about 800 aircraft (up to June 1945) with an overall production of 2460 aircraft until 1952, the majority of them built by aircraft factory number 23 in Moscow.
