Unless the articles of incorporation provide otherwise, if a vacancy occurs on a board of directors, including a vacancy resulting from an increase in the number of directors:
If the vacant office was held by a director elected by a voting group of shareholders, only the holders of shares of that voting group are entitled to vote to fill the vacancy if it is filled by the shareholders.
A vacancy that will occur at a specific later date, by reason of a resignation effective at a later date under § 47-1A-807 or otherwise, may be filled before the vacancy occurs but the new director may not take office until the vacancy occurs.
SDCL 47-1A-810