The corps was re-formed in May 1942 at the Moscow Armored Training Center, nearly a year after Germany had abandoned the Molotov–Ribbentrop Pact and invaded the Soviet Union. Major General Vasily Koptsov took command of the formation, which included the 96th and 113th Tank Brigades, the 105th Heavy Tank Brigade, the 17th Motor Rifle Brigade, and the 5th Reconnaissance Battalion. The corps was assigned to the 3rd Tank Army on 25 May, and as of 2 June included 150 tanks, comprising 30 KV tanks, 60 T-34 tanks, and 60 T-60 light tanks. The corps concentrated in the Tula area with the rest of the army, conducting intensive training exercises. After Axis forces launched the Case Blue summer offensive in southern Russia in late June, Stavka believed that an attack by Army Group Centre on the Oryol axis was possible, and ordered the army to concentrate in the Yefremov area. On 6 July, the army was ordered to concentrate to the west in the Chern area, moving closer to the front. The relocation was completed by 9 July, and the 15th Tank Corps was positioned in the area of the Agnichnoye State Farm, Dupny, Bolshoy Kon, Gremyachevo, Yasnyy Lug, and Korotky, where it engaged in combat training and created a defensive line in readiness to repulse a German attack. Late that month, the 96th Brigade was transferred to the Bryansk Front, and it was replaced by the 195th Tank Brigade between 10 and 12 August.