Citation... For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty while serving as a rifleman with the 3d Battalion, 1st Marines, 1st Marine Division, in action against enemy Japanese forces on Okinawa Shima in the Ryukyu Chain 2 May 1945. Dug in with another marine on the point of the perimeter defense after waging a furious assault against a strongly fortified Japanese position, Pfc. Foster and his comrade engaged in a fierce hand grenade duel with infiltrating enemy soldiers. Suddenly an enemy grenade landed beyond reach in the foxhole. Instantly diving on the deadly missile, Pfc. Foster absorbed the exploding charge in his own body, thereby protecting the other marine from serious injury.

Although mortally wounded as a result of his heroic action, he quickly rallied, handed his own remaining 2 grenades to his comrade and said, "Make them count." Stouthearted and indomitable, he had unhesitatingly relinquished his own chance of survival that his fellow marine might carry on the relentless fight against a fanatic enemy, and his dauntless determination, cool decision and valiant spirit of self-sacrifice in the face of certain death reflect the highest credit upon Pfc. Foster and upon the U.S. Naval Service. He gallantly gave his life in the service of his country.