Law career (1987–2000) Steiner was admitted to the
State Bar of California in December 1988. He worked as an associate at Jones, Walker, Waechter, Poitevent, Carrere & Denegre and
Gibson, Dunn & Crutcher. In 1990, Steiner joined Phelps Dunbar. He specialized in corporate, securities, and mergers and acquisitions law. Steiner was named a partner in February 1995 and subsequently started the firm's pro-bono practice where Steiner said they "help people in need, and need people to help." Steiner married Judy and had three children with her.
Waste Management (2000–2016) In November 2000, Steiner became deputy general counsel for
Waste Management, rejecting a job offer from
Enron. In July 2001, he was appointed general counsel and senior vice president, and in April 2003, Steiner was promoted to chief financial officer. He succeeded A. Maurice Myers as chief executive in March 2004. Steiner became president of Waste Management in June 2010. His tenure marked a shift in the company's marketing towards environmental services. Steiner led an offer to acquire
Republic Services, the second largest waste disposal company in the United States, in 2008. Steiner resigned as president in July 2016 and as chief executive in November.
Board memberships Steiner has served on the board of directors of
FedEx since 2009 and as its lead independent director since 2013. He has additionally served on the board of
TE Connectivity. Steiner joined the boards of
Vulcan Materials Company in February 2017 and AMP Robotics in January 2025. ==Postmaster General==