Max Sieben Baucus (born December 11, 1941) is the senior United States Senator from Montana and a member of the Democratic Party. First elected to the Senate in 1978, as of 2010 he is the longest-serving Senator from Montana, and the fifth longest-serving U.S. Senator currently in office.
As the current chairman of the Senate Committee on Finance, Baucus has played an influential role in the debate over health care reform in the United States. He is also chairman of the Joint Committee on Taxation, and a member of the Senate Committee on Agriculture, Nutrition and Forestry and Senate Committee on Environment and Public Works, and is chairman of the Subcommittee on Transportation and Infrastructure.
Before his election to the Senate, Baucus was a member of the United States House of Representatives from 1975 to 1978, representing Montana's (now defunct) 1st congressional district. He previously served in the Montana House of Representatives from 1973 to 1974.