Geisinger Medical Center (Danville, Pa.). In 1905, 85-year-old Abigail Geisinger founded Geisinger Medical Center, which grew into the flagship facility of the physician-led Geisinger Health System. The health system includes approximately 30,000 employees, 12 hospital campuses, two research centers and a 551,000-member health plan, cumulatively leveraging a $10.5 billion positive impact on the Pennsylvania and New Jersey economies. The hospital is outfitted with a Level I trauma center, a seven-helicopter Life Flight program and clinical research facilities.