Private First Class Lopez was a member of Company K, 3rd Battalion, 21st Infantry Regiment, 24th Infantry Division. He was listed as Missing in Action when his position near Chochiwon, South Korea was overrun by overwhelming North Korean forces on 11 July 1950. He was presumed dead on 31 December 1953. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Lopez was awarded the Purple Heart, the Combat Infantryman Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.