He is a nurse practitioner in the Division of Infectious Diseases at Johns Hopkins Medicine providing HIV and PrEP services. He is a leader in Pre-Exposure Prophylaxis (PrEP) working with the Baltimore City Health Department to implement a city-wide initiative to increase access and retention of PrEP services in men who have sex with men. Dr. Farley leads The Johns Hopkins HIV Prevention Trials Network (HPTN) within the School of Medicine and the Founder of the REACH Initiative of Johns Hopkins University School of Nursing. He is currently the President of the Association of Nurses in AIDS Care (ANAC), the world's largest HIV focused nursing organization.