He is the younger brother of General Peter Schoomaker, USA, who served as the 35th Chief of Staff of the United States Army.

Schoomaker completed his internship and residency in internal medicine at Duke University Medical Center in Durham, North Carolina, from 1976 to 1978, followed by a fellowship in hematology at Duke University Medical Center in 1979.

His military education includes completion of the Combat Care Casualty Course, Medical Management of Chemical Casualty Care Course, AMEDD Officer Advanced Course, Command and General Staff College, and the U.S. Army War College.

He served as Assistant Chief and Program Director, Department of Medicine, Walter Reed Army Medical Center, from 1982 to 1988; Medical Consultant to Headquarters, 7th Medical Command, Heidelberg, Germany, 1988–1990; Deputy Commander for Clinical Services, Landstuhl Army Regional Medical Center, Landstuhl, Germany, 1990–1992; Chief and Program Director, Department of Medicine and Director of Primary Care, Madigan Army Medical Center, Tacoma, Washington, 1992–1995; Director of Medical Education for the Office of The Surgeon General/HQ USAMEDCOM conducting a split operation between Washington, DC, and Fort Sam Houston, Texas, 1995–1997; and Director of Clinical Operations at the HQ USAMEDCOM, February to July 1997.

This article incorporates public domain material from the United States Army