Redistricting authority:  
U.S. Congressional Districts – Legislative.  The U.S. Congress has given the state Legislatures authority to redistrict congressional seats. The only federal statutory requirement is that congressional districts be single-member districts. The Missouri congressional plan is introduced as a regular bill in the legislature and must be passed by both Houses and signed by the Governor who has veto power over the plan. 

State Legislative Districts – Commission. Within 60 days of census information being
available to the state, the congressional district committees of the 2 major parties meet and
nominate by a majority vote 2 members of their party who are residents in the district, as
nominees for Reapportionment Commissioners. This list of nominees is given to the Governor,
who appoints a commission consisting of one name from each list to form the House
reapportionment commission (18 members in all). This commission has 6 months from the time
all members are appointed to submit a plan, and the plan must be approved by 7/10ths of the
members. If the plan is not in place within 6 months, the commission is disbanded, and the state
Supreme Court appoints a 6-member commission from among state appellate judges who must
file a plan within 90 days of the discharge of the commission.

The Governor then forms the Senate committee, choosing from a list of 10 nominees
submitted by the state committee of each political party (10 nominees for each party). The
Governor chooses 5 from each list to compose the 10-member committee, to reapportion the
senatorial districts. This commission has 6 months from the time all members are appointed to hold hearings and submit a plan, and the plan must be approved by 7of the members. If the plan is not in place within 6 months, the commission is disbanded, and the state Supreme Court appoints a 6-member commission from among state appellate judges who must file a plan within 90 days of the discharge of the commission.