Ariz. Rev. Stat. § 10-3811 – Vacancy on board

A. Unless the articles of incorporation or bylaws provide otherwise, and except as provided in subsections B and C of this section, if a vacancy occurs on a board of directors, including a vacancy resulting from an increase in the number of directors, either:
1. 1. The members, if any, may fill the vacancy.
2. 2. The board of directors may fill the vacancy.
3. 3. If the directors remaining in office constitute fewer than a quorum of the board of directors, they may fill the vacancy by the affirmative vote of a majority of all the directors remaining in office.
B. Unless the articles of incorporation or bylaws provide otherwise, if the vacant office was held by a director elected by a class, chapter, region or other organizational or geographic unit or grouping, only members of the class, chapter, region, unit or grouping are entitled to vote to fill the vacancy if it is filled by the members.
C. Unless the articles of incorporation or bylaws provide otherwise, if a vacant office was held by an appointed director, only the person who appointed the director may fill the vacancy.
D. If a vacant office was held by a designated director, the vacancy shall be filled as provided in the articles of incorporation or bylaws. In the absence of an applicable article or bylaw provision, the vacancy may not be filled by the board.
E. A vacancy that will occur at a specific later date by reason of a resignation effective at a later date under section 10-3807, subsection B or otherwise may be filled before the vacancy occurs, but the new director may not take office until the vacancy occurs.
F. If at any time by reason of death or resignation or other cause a corporation has no directors in office, any officer or any member may call a special meeting of members.