Dr. Foley received his Doctor of Medicine degree from UCLA in 1979. He completed neurosurgery residency training at UCLA in 1985.

Following residency, Dr. Foley served in the United States Army Medical Corps as Assistant Chief of Neurosurgery at Brooke Army Medical Center, Chief of Neurosurgery at Tripler Army Medical Center, and Chief of Neurosurgery at Walter Reed Army Medical Center, where he was also the chairman of the neurosurgical residency training program.

In 1992, Dr. Foley left the military and joined Semmes-Murphey Clinic and the Department of Neurosurgery at UTHSC. In addition to a full-time spine surgery practice, he is actively involved in research in minimally invasive spine surgery, image-guided spinal navigation, robotics, spinal biomechanics, clinical outcomes, and disc regeneration. He has over 200 scientific publications to his credit, has lectured at more than 600 scientific meetings and educational workshops, and has been a visiting professor and invited lecturer at numerous universities in the US and abroad. In addition, Dr. Foley has been issued 178 U.S. patents; his inventions include tubular retractors for minimally invasive spinal surgery, methods and devices for image-guided surgery, minimally invasive spinal fixation using screws with percutaneous extenders, bullet-nosed and expanding interbody implants, and methods for deriving and using discogenic cells. In recognition of his accomplishments, Dr. Foley was presented with the American Association of Neurological Surgeons Cushing Award for Technical Excellence and Innovation in Neurosurgery in 2019.