MO Rev Stat § 115.395 (2021)
2021 Missouri Revised Statutes|Title IX - Suffrage and Elections|Chapter 115 - Election Authorities and Conduct of Elections|Section 115.395 - Ballot for each party at primary — candidates, how listed — ballot information, how shown.

Effective - 19 Feb 2014   115.395. Ballot for each party at primary — candidates, how listed — ballot information, how shown. — 1. At each primary election, there shall be as many separate ballots as there are parties entitled to participate in the election.  2. The names of the candidates for each office on each party ballot shall be listed in the order in which they are filed, except that, in the case of candidates who file a declaration of candidacy with the secretary of state prior to 5:00 p.m. on the first day for filing, the secretary of state shall determine by random drawing the order in which such candidates' names shall appear on the ballot. The drawing shall be conducted so that each candidate, or candidate's representative if the candidate filed under subsection 2 of section 115.355, may draw a number at random at the time of filing. The secretary of state shall record the number drawn with the candidate's declaration of candidacy. The names of candidates filing on the first day for filing for each office on each party ballot shall be listed in ascending order of the numbers so drawn. For the purposes of this subsection, the election authority responsible for oversight of the filing of candidates, other than candidates that file with the secretary of state, shall clearly designate where candidates, or a candidate's representative if the candidate filed under subsection 2 of section 115.355, shall form a line to effectuate such filings and determine the order of such filings; except that, in the case of candidates who file a declaration of candidacy with the election authority prior to 5:00 p.m. on the first day for filing, the election authority may determine by random drawing the order in which such candidates' names shall appear on the ballot. If a drawing is conducted pursuant to this subsection, it shall be conducted so that each candidate, or candidate's representative if the candidate filed under subsection 2 of section 115.355, may draw a number at random at the time of filing. If such drawing is conducted, the election authority shall record the number drawn with the candidate's declaration of candidacy. If such drawing is conducted, the names of candidates filing on the first day for filing for each office on each party ballot shall be listed in ascending order of the numbers so drawn.  3. Insofar as applicable, the provisions of sections 115.237 and 115.245 shall apply to each ballot prepared for a primary election, except that the ballot information may be placed in vertical or horizontal rows, no circle shall appear under any party name and no write-in lines shall appear under the name of any office for which a candidate is to be nominated at the primary. At a primary election, write-in votes shall be counted only for persons who can be elected to an office at the primary. ­­-------- (L. 1977 H.B. 101 § 10.180, A.L. 1995 H.B. 484, et al., A.L. 1997 S.B. 132, A.L. 2014 H.B. 1125)  Effective 2-19-14