The apportionment of seats in the House of Representatives was based on the 1980 United States census.

The Republicans maintained control of the Senate, while the Democrats maintained control of the House of Representatives – albeit with both majorities slightly reduced from the 98th Congress.

Senators are popularly elected statewide every six years, with one-third beginning new six-year terms with each Congress, In this Congress, Class 3 meant their term ended with this Congress, facing re-election in 1986; Class 1 meant their term began in the last Congress, facing re-election in 1988; and Class 2 meant their term began in this Congress, facing re-election in 1990.

Lists of committees and their party leaders for members of the House and Senate committees can be found through the Official Congressional Directory at the bottom of this article.

The directory after the pages of terms of service lists committees of the Senate, House (Standing with Subcommittees, Select and Special) and Joint and, after that, House/Senate committee assignments.