Unless Democratic Gov. Jay Nixon vetoes it, Missouri has a new map for the eight congressional districts that go into effect in January 2013.
The state Constitution requires lawmakers to redraw congressional district boundaries every 10 years after the official U.S. Census numbers are released.
Because Missouri didn't grow as quickly as other states, Missouri loses a congressional district, making the redistricting job more difficult.
Candidates for the new districts will be on the November 2012 election ballot.
House and Senate negotiators released their "Grand Compromise" proposal for congressional redistricting late Wednesday afternoon.
The House approved it on a 96-55 vote.
The Senate then passed it on a 27-7 vote, sending the plan to Nixon.