Dr. Kostic is a native of Pennsylvania, and a 1994 graduate of Jefferson Medical College. After medical school, he spent over 13 years on active duty with the US Navy, completing his residency training in emergency medicine at Naval Medical Center, San Diego, and his fellowship in medical toxicology at the Rocky Mountain Poison and Drug Center in Denver in 2003. While in Virginia with the Navy, he served as both Medical Director and Associate Medical Director of the Virginia Poison Center. He joined the Wisconsin Poison Center in 2007 as its Associate Medical Director, He is currently a Professor of Emergency Medicine with the Medical College of Wisconsin.
He has served as the President of the American Academy of Clinical Toxicology since October of 2018.