Dr. Mendelson was born and raised in Wilmington, Delaware. He attended Cornell University, where he graduated Magna Cum Laude with Bachelor in Arts in Biological Sciences. He completed medical school at Thomas Jefferson University in Philadelphia, where he earned his M.D. and graduated Magna Cum Laude. He then went on to the Hospital of the University of Pennsylvania and completed his residency in internal medicine. After residency, he completed his fellowship training in Gastroenterology and Hepatology at the Johns Hopkins Hospital. He currently resides in Allentown with his wife and two children. He enjoys long distance running, routing for the Philadelphia Eagles, and spending quality time with his family.