ALL of the justices will be up for reelection in 2020. If they are opposed by someone of the same party, they will appear on the March 2020 primary ballot.
Arkansas County Judges 2018 Procedures Manual
The legislative body of county government is called the quorum court and is composed of 9, 11, 13 or 15 members depending on the population of the county. The quorum court members are called justices of the peace and are elected for two-year terms from districts within the county. These district officials meet each month, more often if necessary, to conduct county business and review ordinances and resolutions for passage. The county judge is the presiding officer over the quorum court without a vote, but with the power of veto. This veto can be overridden with a 3/5ths vote of the total membership of the quorum court.