Korean War Medal of Honor Recipient. He is missing in action (MIA). He served in the United States Army as a Corporal, Acting Machine Gunner in the 11th Airborne Division and was killed in action (KIA) on Hill 171, near Kangong, Korea.

His Medal of Honor was presented to his brother, Charles Baldonado, in the White House by President Barack Obama on March 18, 2014. His Medal of Honor citation reads: Corporal Joe R. Baldonado distinguished himself by acts of gallantry and intrepidity above and beyond the call of duty while serving as an acting machine gunner in 3rd Squad, 2nd Platoon, Company B, 187th Airborne Infantry Regiment, during combat operations against an armed enemy in Kangdong, Korea, on November 25, 1950. On that morning, the enemy launched a strong attack in an effort to seize the hill occupied by Corporal Baldonado and his company. The platoon had expended most of its ammunition in repelling the enemy attack, and the platoon leader decided to commit his 3rd Squad, with its supply of ammunition, in the defensive action. Since there was no time to dig in because of the proximity of the enemy who had advanced to within twenty-five yards of the platoon position, Corporal Baldonado emplaced his weapon in an exposed position and delivered a withering stream of fire on the advancing enemy, causing them to fall back in disorder. The enemy then concentrated all their fire on Corporal Baldonado's gun and attempted to knock it out by rushing the position in small groups and hurling hand grenades. Several times, grenades exploded extremely close to Corporal Baldonado but failed to interrupt his continuous firing. The hostile troops made repeated attempts to storm his position and were driven back each time with appalling casualties. The enemy finally withdrew after making a final assault on Corporal Baldonado's position, during which a grenade landed near his gun, killing him instantly. Corporal Baldonado's extraordinary heroism and selflessness at the cost of his own life, above and beyond the call of duty, are in keeping with the highest traditions of military service and reflect great credit upon himself, his unit, and the United States Army."