Trustee , Prev Next Larry Appel, MD, MPH Trustee Director, Welch Center for Prevention, Epidemiology and Clinical Research, The Johns Hopkins University Professor of Medicine Need Help? If you need help finding the right member of our staff for your needs, please reach out to us via the Contact Us page. Horizon Foundation 10221 Wincopin Circle, Suite 200Columbia, MD 21044United States410-715-0311