He was a Robert Wood Johnson Health Policy Fellow from 2012-13, assigned to the U.S. Congress, Congressional Budget Office, (CBO), and served as Assistant Deputy Commander for Healthcare Operations and Strategic Planning at Walter Reed National Military Medical Center (WRNMMC) during its integration. Currently, Tetteh is a Thoracic Staff Surgeon for MedStar Health and WRNMMC and most recently served as Command Surgeon for the National Defense University.