Bill grew up in Baton Rouge, Louisiana, and attended Louisiana State University (LSU) for undergraduate and medical school. In 1990, Bill joined LSU Medical School teaching medical students and residents at Earl K. Long Hospital, a hospital for the uninsured. 

During this time, he co-founded the Greater Baton Rouge Community Clinic, a clinic providing free dental and health care to the working uninsured. Bill also created a private-public partnership to vaccinate 36,000 greater Baton Rouge area children against Hepatitis B at no cost to the schools or parents. In the wake of Hurricane Katrina, Bill led a group of health care volunteers to convert an abandoned K-Mart building into an emergency health care facility, providing basic health care to hurricane evacuees.

In 2006, Bill was elected to the Louisiana State Senate.

In 2008, he was elected to the United States House of Representatives to represent Louisiana’s Sixth Congressional District.

In 2014, he was elected to the U.S. Senate. He serves on the Finance Committee, the Health, Education, Labor, & Pensions Committee, the Energy and Natural Resources Committee, and the Veterans Affairs committees.