In the private sector, Dr. Do is a practicing cardiologist and the director of the American Executive Health System, a multi-specialty medical group in Virginia. He is a current board member for the INOVA Signature Partner Account Care Organization, one of the largest ACO in the Northern Virginia area. Dr. Do had served in the U.S. Army with the rank of major. While in U.S. Army, he served multiple leadership roles at the Malcolm Grow Medical Center as director of the Coronary Care Unit, director of the Non-invasive Labs, and later as the director for the Pacemaker Implantation Services. He had also served as the vice-president of the Vietnamese American Medical Association. Dr. Do graduated with honor with a degree in chemistry at the University of California, Berkeley.