On 4 July KG 100 moved to Poltava and participated in the Battle of Kursk to 16 July. It flew in support of the Mius River front near Kharkov and Izium in August. The group was particularly active along the front from Konotop and Zaporozhye. From Kirovograd it flew attacks against Soviet bridgeheads at Kremenchug and Zaporozhye in October in midst of the Battle of the Dnieper. I./KG 100 traded identities with I./KG 4 on 21 October 1943. The group was reformed and KG 100 left the Eastern Front.
