Our Providers & Staff


David L. Siegel, M.D.

Dr. Siegel of Baltimore completed electrical engineering training at Columbia University and went on to graduate from the University of Maryland Medical School in 1979. He completed a residency in internal medicine and a fellowship in gastroenterology jointly at the Baltimore City Hospital and Johns Hopkins Hospital. Dr. Siegel is the chairman of the Greenbelt Endoscopy Center.


James Y. Wang, M.D.

Dr. Wang was born in Silver Spring, Maryland and grew up in Michigan. He attended the University of Michigan where he received a degree in economics. From there he went on to complete medical school in 1996 and an internal medicine residency at the University of Maryland. Having left behind Michigan’s invigorating winters for Maryland’s milder climate, he is very excited to be remaining here as a member of Bowie Internal Medicine Associates. Dr. Wang has a strong interest in preventative medicine, with a particular interest in diabetes and cardiovascular disease.


Ritu M. Sachdev, M.D.

Dr. Sachdev received her medical degree from Maulana Azad Medical College in Delhi University in 1999. She completed her internal medicine residency at Tufts University and her fellowship in gastroenterology at Baylor College of Medicine. Following training, she worked in private practice in Annapolis for three years.

Dr. Sachdev is board certified in Gastroenterology/Hepatology and Internal Medicine. She is a member of American College of Gastreoenterology and American Gastroenterology Association. Dr. Sachdev has special interests in multiple areas of gastroenterology, including inflammatory bowel disease, reflux, Barrett’s esophagus and colorectal cancer screening.

Dr. Sachdev joined Bowie Internal Medicine in 2012 as a gastroenterologist. She brings with her a compassionate approach to patient care, and a special focus in women’s health and preventive medicine in gastroenterology.


Lizy Thomas, M.D.

Prior to joining Bowie Internal Medicine, Dr. Thomas worked as an internist in the Washington, D.C. area for 15 years.

Dr. Thomas completed her internal medicine residency at Harbor Hospital Center, Baltimore, a major affiliate of the University of Maryland in 1999. Dr. Thomas is board certified in internal medicine, and is a member of The American College of Physicians. Her special interests are women’s health and diabetes.


Janet M. Beebe, C.R.N.P.

Mrs. Beebe is a native of Washington State. She received her Bachelor’s of Science in Nursing from the University of Washington in Seattle in 1984. Mrs. Beebe is a 1999 graduate of the University of Maryland’s School of Nursing where she obtained a Masters of Science in Adult Primary Care and Mental Health Nursing and is now a C.R.N.P. (certified nurse practitioner) for our practice.


Jo Alderman Greenberg, C.R.N.P.

Jo Greenberg, CRNP, is an experienced medical professional who earned a Bachelor of Science in Psychology from Virginia Tech and a Bachelor of Science in Nursing from the Medical College of Virginia. In 1997, she received her Master’s degree in Nursing from The Johns Hopkins University. Her strong interests in preventive care and cardiology led her to Bowie Internal Medicine Associates. Before joining us, Jo served patients in a family practice in Hunt Valley. Jo is married and has three daughters. When not treating patients, she enjoys spending time with family and friends, fitness, reading, and watching the Ravens and the Virginia Tech Hokies play football.



Stephanie McConkey, Office Manager

Stephanie McConkey was born in Durham, North Carolina and spent her early childhood there until moving to Bowie Maryland with her family. She graduated from high school in 1983. Then she went on to study business at Prince George’s Community College. Before coming to Bowie Internal Medicine in 2008, she worked for Dr. William Rosson of New Carrollton, Maryland for 18 years. Stephanie is married and has 3 children. She enjoyed being involved in her two older children’s sporting activities from the time they were 5 through high school age. Now she is enjoying her younger daughter who is involved in cheerleading and soccer.