In the winter of 1942/43, Fretter-Pico led the Fretter-Pico army division (German: "Armeeabteilung Fretter-Pico"), which was temporarily formed from his corps, and then again the XXX. Army Corps. At the beginning of July 1944 he was briefly reassigned to the Führerreserve in order to take over command of the 6th Army in the middle of the month, which was destroyed a little later during the Soviet Jassy-Kishinev operation and then had to be reorganized. Due to the subordination of the Hungarian 2nd and 3rd Army, it was temporarily referred to as the Army Group Fretter-Pico (German: "Armeegruppe Fretter-Pico"). This formation took part in the Battle of Debrecen, from 6 to 29 October 1944. On 23 December 1944 he gave up his command and was z. b. V. of the Army High Command. This put him on 25 March 1945 as an assessor in the court martial in Torgau against the "General der Panzertruppe" Walter Fries. Contrary to Hitler's express order, Fries had given up the city of Warsaw, which had been declared a fortress (German: "Festung"), and had the German troops withdrawn. The trial ended on 30 March 1945 with Fries' acquittal and Fretter-Pico was appointed commander of military district IX, based in Kassel (German: ""), this being his last command. There he was taken prisoner by the US Army on 22 April 1945 being released in mid-1947.