Private First Class Hubbard was a medic with the Medical Company, 38th Infantry Regiment, 2nd Infantry Division. He was taken Prisoner of War while tending his wounded comrades in North Korea on 26 November 1950 and died while a prisoner on 5 February 1951. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Hubbard was awarded the Combat Medical Badge, the Prisoner of War Medal, 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.