Louis in 2003 to become chief medical officer at Express Scripts, a Fortune 100 Company. After retiring from that position in 2010, he began organizing the St. Louis chapter of Physicians for a National Health Program, which he currently chairs. He volunteers in a variety of safety-net clinics in the St. Louis area, and is also assistant professor of clinical medicine at Washington University in St. Louis. He has had several articles published in national medical journals regarding the health care needs of the uninsured, and the St. Louis Post-Dispatch has printed several of his opinion pieces about single-payer health care. He has also testified multiple times before the Missouri Legislature on health care reform. He resides in Creve Coeur, Mo.