Wis. Stat. § 65.025: Biennial budget procedures.

(1) A city may adopt a biennial budget by implementing the procedures under this section and using the procedures under ss. 65.02 to 65.20. If a city chooses to adopt a biennial budget, it shall adopt such a budget in an odd-numbered year for the next 2 fiscal years that follow immediately the year in which the budget is adopted.

(2) For a city to proceed under this section, the common council shall adopt a resolution or enact an ordinance stating its intent to adopt a biennial budget. Once a resolution is adopted or an ordinance is enacted, such an action takes effect and may not be reconsidered or repealed, except as provided in sub. (3).

(3) A common council that has adopted a biennial budget procedure as provided in this section may return to the use of an annual budget procedure if the common council, by a two-thirds majority vote, adopts a resolution or enacts an ordinance stating its intent to adopt an annual budget.

(4) A common council or a committee authorized by the common council may, at any time, decrease appropriation amounts in a biennial budget.

(5) In October or November of an even-numbered year, the common council may change any appropriation or revenue amount in relation to the 2nd year of the biennial budget by a simple majority vote of the members-elect, as defined in s. 59.001 (2m).