SB/SE, one of four operating divisions within the IRS, employs almost 44,000 workers and oversees the compliance programs for all individuals and small businesses. It serves 45 million taxpayers.

Brown is currently chief of staff to IRS Commissioner Mark W. Everson. Replacing Brown as chief of staff to the commissioner will be Evelyn Petschek. Petschek is currently the commissioner of the Tax-Exempt and Government Entities Division.

Brown previously served as SB/SE Division Counsel. He joined the IRS in 1998 as Assistant to the Commissioner. He also participated in advising the agency during the Restructuring and Reform Act of 1998. He worked as an attorney at the Justice Department from 1987 until 1998.

Petschek, who has been with the IRS since 1993, has been commissioner of the Tax-Exempt and Government Entities Division since its inception in 1999. Before joining the IRS, Petschek served in the Treasury Department's Office of Tax Policy as benefits tax counsel. The TEGE function, one of four operating divisions within the IRS, employs 2,400 workers and serves 3 million taxpayers.