Prior to his teaching position at Penn State, he was a post-doctoral fellow for the U.S. Department of Energy at Brooke Army Medical Center in Fort Sam Houston in San Antonio, Texas. As a postdoc, he provided analytical expertise to projects in the areas of Military Health and Burn Rehabilitation. Santos-Lozada was born to Puerto Rican parents. He is a population health scientist whose research examines policy implications of demographic trends in the United States and around the globe.