Beikirch joined the United States Army in August 1967, just after finishing his second year of college in upstate New York. He was interested in becoming a Green Beret from the very beginning. He completed basic training at Fort Dix, New Jersey, and then went on to Fort Benning, Georgia, for jump school. He completed jump school, passed the Special Forces test and went on to training at Fort Bragg, North Carolina. After finishing phase one special forces training, he completed training to become a combat medic. During his time in the army, Beikirch served with the 3rd, 5th and 10th Special Forces Groups as a Light Weapons and Medical Specialist. He was sent to Vietnam in July 1969.