Tsou is a nationally known consultant on public health and health care reform. Currently, he is an Adjunct Professor of Family Medicine and Community Health at the University of Pennsylvania where he teaches community health at their Center for Public Health Initiatives. He was President of the American Public Health Association in 2005. He served as Health Commissioner of Philadelphia from April 2000 to February 2002. Prior to his appointment, he was the founding Deputy Director for Personal Health Services and Medical Director of the Montgomery County (PA) Health Department from 1991-2000. He has extensive experience in public health and has lectured widely on public health and health disparities.
Nationally, he is a Board Advisor at Physicians for a National Health Program and Healthcare-NOW. He is the Past Chair of the Board of the Asian Pacific Islander American Health Forum. Locally he is on the boards of Physicians for Social Responsibility Pennsylvania, Hepatitis B Foundation, Health Care for All Pennsylvania. His medical degree is from the University of Pennsylvania; his MPH is from the Johns Hopkins School of Hygiene and Public Health, and he has an honorary Doctorate in Medical Sciences from Drexel University.