Stephen Thomas has focused his career on understanding how social context shapes attitudes and behaviors of underserved, poorly served, and never-served segments of our society toward participation in health promotion and disease prevention activities. Thomas is particularly interested in how the legacy of the syphilis study at Tuskegee (1932–72) has impacted trust and influenced the willingness of African Americans to participate in medical and public health research.
In 2014, democratic governor O’Malley appointed Thomas to the Maryland Health Care Commission, an independent regulatory agency whose mission is to plan for health system needs, promote informed decision-making, increase accountability, and improve access to quality medical and dental care. In 2019, republican governor Hogan appointed him to a new full term on the commission.