Dr. Fidel Castillo is an Assistant Professor of Medicine in the Geriatrics Fellowship at the Department of Medicine and Geriatrics of UIC. He started his medical degree (MD) at the Autonomous University of Costa Rica, and went on to earn his Residency in Internal Medicine in the San Juan City Hospital in Puerto Rico in 2007. He has also completed Subspecialty Fellowships in Geriatrics at UIC in 2009.

Dr. Castillo is ABIM board certified in Internal Medicine. He is actively taking part in community and academic roles such as: board of directives in Urban and Global Health at UIC, Chair of the Geriatric Fellowship evaluation committee, Board Member of the Dementia committee at Jesse Brown VA Hospital and now a board directive member of Medical Organization for Latino Advancement.

Dr. Castillo has various clinical interests in the healthcare of geriatric population and in general public health such as healthcare disparities. His current research investigations underlie frailty syndrome in the elderly, falls and retraining gait interventions in the elder population.