Iowa Code § 182.8: Terms.

The term of office for members of the board shall be three years. The members on the initial board shall determine their terms by lot, so that three members shall serve a one-year term, three members shall serve a two-year term, and three members shall serve a three-year term. A member elected to the initial board shall not serve more than two complete consecutive terms. A member subsequently elected to the board shall not serve more than a certain number of consecutive terms if, and as may be, established by the board.