Filing will open Tuesday, Dec. 12, for city offices on the April 3, 2018, municipal election ballot.
The mayor, four city council seats and the office of city attorney will be on the ballot.
Filing will close at 5 p.m. Tuesday, Jan. 16, 2018.
Mayor Sandy Lucy stated in November that she intends to seek a third term as mayor.
Incumbent council members whose terms will expire next April are Steve Sullentrup, Ward 1; Mark Hidritch, Ward 2; Greg Skornia, Ward 3; and Josh Brinker, Ward 4.
Mark Piontek is the incumbent city attorney. Piontek was first elected city attorney in 1988.
Candidates for mayor must be at least 30 years old and a resident of the city for at least two years preceding his or her election.
Candidates for council seats must be at least 21 years old and be a Washington resident for one year and a resident of their ward for six months.
There is no age restriction for the city attorney. However, he or she must be licensed to practice law in Missouri.