Hann joined the National Institutes of Health (NIH) in 1991 as a program officer and chief of the Interpersonal and Family Processes Program within the National Institute of Mental Health (NIMH) Behavioral, Cognitive, and Social Sciences Research Branch.[1] She has since held a variety of leadership roles both within NIMH and the NIH Office of Extramural Research (OER), including senior policy advisor in OER and director of the Office of Science Policy, Planning and Communications at NIMH.