Mummert later led the 14th Panzer Reconnaissance Battalion of the reformed 14th Panzer Division, the original having been destroyed in the Battle of Stalingrad. His leadership style often saw him on the frontlines with his infantry and engaged in close combat, and he received several badges in recognition of this; the Panzer Badge and Close Combat Clasp, both in bronze, as well as the Tank Destruction Badge for Individual Combatants. He was given command of the 14th Panzer Division's 103rd Panzer Grenadier Regiment in January 1944. Promoted to "Oberstleutnant" (lieutenant colonel), he was awarded the Oak Leaves to his Knight's Cross. Nine months later, and now an "oberst" (colonel), he briefly led the 14th Panzer Division as its temporary commander. In October 1944, he was awarded the Swords to the Knight's Cross, the 107th recipient of this award.