Ind. Code § 22-8-1.1-32.1
Board: Terms. Members of the board shall be appointed for terms of four (4) years, and until their successors are appointed and qualified. Of the members first appointed, the members appointed who are drawn from those who have backgrounds with management shall be appointed to terms so that in every other year the term of one (1) or the other of them ends; and the members who are drawn from those who have backgrounds with labor organizations shall be appointed so that every other year the term of one (1) or the other of them ends. The first chairman of the board shall have a four (4) year term. Vacancies shall be filled in the same manner as the original appointments, except that a vacancy occurring during the term of office shall be filled by appointment of the governor for the unexpired term.
IC 22-8-1.1-32.1