In 1986, at age 41, Brown was hired as CEO of Christian Health System in St. Louis (seen here at a board seminar that year). Before he was 50 CHS would become a party to one of the early megamergers in not-for-profit healthcare, and he would be the combined system's CEO.
When approached about leading the newly affiliated Barnes and Jewish hospitals in 1992, Brown pressed them to consolidate with Christian Health System. A year later, that's what happened, forming BJC Health System. Missouri Baptist Medical Center and St. Louis Children's Hospital join BJC in 1994.