Dr. Horberg is the director of HIV/AIDS nationally for KP, serving nearly 80,000 members with HIV, as well as Clinical Lead for HIV/AIDS and STI, creating clinical multidisciplinary guidelines to improve such care in KP. He has chaired the KP HIV, Liver Disease, STI, and LGBTQ Health Conference since 2003, bringing together clinical and research staff to ensure best practices.

Dr. Horberg leads HIV, STI, and Infection Prevention for MAPMG. He directs LGBTQI+ care and led creation of Pride Medical and Gender Pathways clinics within KPMAS. In his role as medical director for KPMAS Community Health and chief medical officer for KPMAS Maryland and Virginia Medicaid, he works to improve health equity and care access for underserved populations in the region.