N.D. Cent. Code § 40-04-01
Any city in this state having a population of not less than five hundred inhabitants may become incorporated as a city under the commission system of government as provided in this section. If one-tenth of the qualified electors of the municipality, based upon the votes cast for the office of governor at the last preceding general election, petition the governing body of the municipality to submit to a vote of the qualified electors the question of whether the city shall become incorporated as a city under the commission system of government, the governing body shall submit the question to the qualified electors, appoint a time when and place or places where the election shall be held, and designate the judges and clerks at the election. The question may not be submitted more than once in every four years.
N.D.C.C. § 40-04-01