Dr. Chapman has practiced in Washington, DC for over 40 years specializing in Internal Medicine and Addiction Medicine. He is board certified in internal medicine and a Fellow of the American Society of Addiction Medicine investigating the complex mix of addiction, undertreated mental illness, infectious diseases (AIDS & hepatitis C), criminal behavior, and chronic diseases in which patients have 20-25-year shorter life expectancies. In January 2019 he was appointed to the National Academy of Science Engineering and Medicine committee “Examination of the Integration of Opioid and Infectious Diseases Prevention Efforts in Select Programs” and currently collaborates with the Howard University School of Pharmacy and College of Medicine as an adjunct assistant professor in the Department of Behavioral Health and Psychiatry.

Dr. Chapman is a nationally recognized leader in efforts to integrate substance use disorder treatment and psychiatry seamlessly into general medical practice. Recognizing the broad social and spiritual needs of his patients, he is a founding member and secretary of the board of directors of the Leadership Council for Healthy Communities (an inter faith 501 c3 with 30+ Metro DC institutions). He has been featured in numerous local and national media including NPR, The Washington Post, EBONY MAGAZINE, Addiction Professional, WUSA in DC, and several international Spanish TV outlets. He was the 2016 National Medical Association “Practitioner of the Year,” Prince George’s County Links, Inc 40th Anniversary 1st awardee for “Excellence in Health and Human Services,” and the Black Mental Health Alliance for Education and Counseling “2019 Phoenix Arising Behavioral Health Provider of the Year Award.”